Merge branch 'gp/branch'
[git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "delta.h"
9 #include "xdiff-interface.h"
10 #include "color.h"
11 #include "attr.h"
12
13 #ifdef NO_FAST_WORKING_DIRECTORY
14 #define FAST_WORKING_DIRECTORY 0
15 #else
16 #define FAST_WORKING_DIRECTORY 1
17 #endif
18
19 static int diff_detect_rename_default;
20 static int diff_rename_limit_default = -1;
21 static int diff_use_color_default;
22
23 static char diff_colors[][COLOR_MAXLEN] = {
24         "\033[m",       /* reset */
25         "",             /* PLAIN (normal) */
26         "\033[1m",      /* METAINFO (bold) */
27         "\033[36m",     /* FRAGINFO (cyan) */
28         "\033[31m",     /* OLD (red) */
29         "\033[32m",     /* NEW (green) */
30         "\033[33m",     /* COMMIT (yellow) */
31         "\033[41m",     /* WHITESPACE (red background) */
32 };
33
34 static int parse_diff_color_slot(const char *var, int ofs)
35 {
36         if (!strcasecmp(var+ofs, "plain"))
37                 return DIFF_PLAIN;
38         if (!strcasecmp(var+ofs, "meta"))
39                 return DIFF_METAINFO;
40         if (!strcasecmp(var+ofs, "frag"))
41                 return DIFF_FRAGINFO;
42         if (!strcasecmp(var+ofs, "old"))
43                 return DIFF_FILE_OLD;
44         if (!strcasecmp(var+ofs, "new"))
45                 return DIFF_FILE_NEW;
46         if (!strcasecmp(var+ofs, "commit"))
47                 return DIFF_COMMIT;
48         if (!strcasecmp(var+ofs, "whitespace"))
49                 return DIFF_WHITESPACE;
50         die("bad config variable '%s'", var);
51 }
52
53 static struct ll_diff_driver {
54         const char *name;
55         struct ll_diff_driver *next;
56         char *cmd;
57 } *user_diff, **user_diff_tail;
58
59 /*
60  * Currently there is only "diff.<drivername>.command" variable;
61  * because there are "diff.color.<slot>" variables, we are parsing
62  * this in a bit convoluted way to allow low level diff driver
63  * called "color".
64  */
65 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
66 {
67         const char *name;
68         int namelen;
69         struct ll_diff_driver *drv;
70
71         name = var + 5;
72         namelen = ep - name;
73         for (drv = user_diff; drv; drv = drv->next)
74                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
75                         break;
76         if (!drv) {
77                 char *namebuf;
78                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
79                 namebuf = xmalloc(namelen + 1);
80                 memcpy(namebuf, name, namelen);
81                 namebuf[namelen] = 0;
82                 drv->name = namebuf;
83                 drv->next = NULL;
84                 if (!user_diff_tail)
85                         user_diff_tail = &user_diff;
86                 *user_diff_tail = drv;
87                 user_diff_tail = &(drv->next);
88         }
89
90         if (!value)
91                 return error("%s: lacks value", var);
92         drv->cmd = strdup(value);
93         return 0;
94 }
95
96 /*
97  * These are to give UI layer defaults.
98  * The core-level commands such as git-diff-files should
99  * never be affected by the setting of diff.renames
100  * the user happens to have in the configuration file.
101  */
102 int git_diff_ui_config(const char *var, const char *value)
103 {
104         if (!strcmp(var, "diff.renamelimit")) {
105                 diff_rename_limit_default = git_config_int(var, value);
106                 return 0;
107         }
108         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
109                 diff_use_color_default = git_config_colorbool(var, value);
110                 return 0;
111         }
112         if (!strcmp(var, "diff.renames")) {
113                 if (!value)
114                         diff_detect_rename_default = DIFF_DETECT_RENAME;
115                 else if (!strcasecmp(value, "copies") ||
116                          !strcasecmp(value, "copy"))
117                         diff_detect_rename_default = DIFF_DETECT_COPY;
118                 else if (git_config_bool(var,value))
119                         diff_detect_rename_default = DIFF_DETECT_RENAME;
120                 return 0;
121         }
122         if (!prefixcmp(var, "diff.")) {
123                 const char *ep = strrchr(var, '.');
124
125                 if (ep != var + 4 && !strcmp(ep, ".command"))
126                         return parse_lldiff_command(var, ep, value);
127         }
128         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
129                 int slot = parse_diff_color_slot(var, 11);
130                 color_parse(value, var, diff_colors[slot]);
131                 return 0;
132         }
133
134         return git_default_config(var, value);
135 }
136
137 static char *quote_one(const char *str)
138 {
139         int needlen;
140         char *xp;
141
142         if (!str)
143                 return NULL;
144         needlen = quote_c_style(str, NULL, NULL, 0);
145         if (!needlen)
146                 return xstrdup(str);
147         xp = xmalloc(needlen + 1);
148         quote_c_style(str, xp, NULL, 0);
149         return xp;
150 }
151
152 static char *quote_two(const char *one, const char *two)
153 {
154         int need_one = quote_c_style(one, NULL, NULL, 1);
155         int need_two = quote_c_style(two, NULL, NULL, 1);
156         char *xp;
157
158         if (need_one + need_two) {
159                 if (!need_one) need_one = strlen(one);
160                 if (!need_two) need_one = strlen(two);
161
162                 xp = xmalloc(need_one + need_two + 3);
163                 xp[0] = '"';
164                 quote_c_style(one, xp + 1, NULL, 1);
165                 quote_c_style(two, xp + need_one + 1, NULL, 1);
166                 strcpy(xp + need_one + need_two + 1, "\"");
167                 return xp;
168         }
169         need_one = strlen(one);
170         need_two = strlen(two);
171         xp = xmalloc(need_one + need_two + 1);
172         strcpy(xp, one);
173         strcpy(xp + need_one, two);
174         return xp;
175 }
176
177 static const char *external_diff(void)
178 {
179         static const char *external_diff_cmd = NULL;
180         static int done_preparing = 0;
181
182         if (done_preparing)
183                 return external_diff_cmd;
184         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
185         done_preparing = 1;
186         return external_diff_cmd;
187 }
188
189 static struct diff_tempfile {
190         const char *name; /* filename external diff should read from */
191         char hex[41];
192         char mode[10];
193         char tmp_path[PATH_MAX];
194 } diff_temp[2];
195
196 static int count_lines(const char *data, int size)
197 {
198         int count, ch, completely_empty = 1, nl_just_seen = 0;
199         count = 0;
200         while (0 < size--) {
201                 ch = *data++;
202                 if (ch == '\n') {
203                         count++;
204                         nl_just_seen = 1;
205                         completely_empty = 0;
206                 }
207                 else {
208                         nl_just_seen = 0;
209                         completely_empty = 0;
210                 }
211         }
212         if (completely_empty)
213                 return 0;
214         if (!nl_just_seen)
215                 count++; /* no trailing newline */
216         return count;
217 }
218
219 static void print_line_count(int count)
220 {
221         switch (count) {
222         case 0:
223                 printf("0,0");
224                 break;
225         case 1:
226                 printf("1");
227                 break;
228         default:
229                 printf("1,%d", count);
230                 break;
231         }
232 }
233
234 static void copy_file(int prefix, const char *data, int size,
235                 const char *set, const char *reset)
236 {
237         int ch, nl_just_seen = 1;
238         while (0 < size--) {
239                 ch = *data++;
240                 if (nl_just_seen) {
241                         fputs(set, stdout);
242                         putchar(prefix);
243                 }
244                 if (ch == '\n') {
245                         nl_just_seen = 1;
246                         fputs(reset, stdout);
247                 } else
248                         nl_just_seen = 0;
249                 putchar(ch);
250         }
251         if (!nl_just_seen)
252                 printf("%s\n\\ No newline at end of file\n", reset);
253 }
254
255 static void emit_rewrite_diff(const char *name_a,
256                               const char *name_b,
257                               struct diff_filespec *one,
258                               struct diff_filespec *two,
259                               int color_diff)
260 {
261         int lc_a, lc_b;
262         const char *name_a_tab, *name_b_tab;
263         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
264         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
265         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
266         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
267         const char *reset = diff_get_color(color_diff, DIFF_RESET);
268
269         name_a += (*name_a == '/');
270         name_b += (*name_b == '/');
271         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
272         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
273
274         diff_populate_filespec(one, 0);
275         diff_populate_filespec(two, 0);
276         lc_a = count_lines(one->data, one->size);
277         lc_b = count_lines(two->data, two->size);
278         printf("%s--- a/%s%s%s\n%s+++ b/%s%s%s\n%s@@ -",
279                metainfo, name_a, name_a_tab, reset,
280                metainfo, name_b, name_b_tab, reset, fraginfo);
281         print_line_count(lc_a);
282         printf(" +");
283         print_line_count(lc_b);
284         printf(" @@%s\n", reset);
285         if (lc_a)
286                 copy_file('-', one->data, one->size, old, reset);
287         if (lc_b)
288                 copy_file('+', two->data, two->size, new, reset);
289 }
290
291 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
292 {
293         if (!DIFF_FILE_VALID(one)) {
294                 mf->ptr = (char *)""; /* does not matter */
295                 mf->size = 0;
296                 return 0;
297         }
298         else if (diff_populate_filespec(one, 0))
299                 return -1;
300         mf->ptr = one->data;
301         mf->size = one->size;
302         return 0;
303 }
304
305 struct diff_words_buffer {
306         mmfile_t text;
307         long alloc;
308         long current; /* output pointer */
309         int suppressed_newline;
310 };
311
312 static void diff_words_append(char *line, unsigned long len,
313                 struct diff_words_buffer *buffer)
314 {
315         if (buffer->text.size + len > buffer->alloc) {
316                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
317                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
318         }
319         line++;
320         len--;
321         memcpy(buffer->text.ptr + buffer->text.size, line, len);
322         buffer->text.size += len;
323 }
324
325 struct diff_words_data {
326         struct xdiff_emit_state xm;
327         struct diff_words_buffer minus, plus;
328 };
329
330 static void print_word(struct diff_words_buffer *buffer, int len, int color,
331                 int suppress_newline)
332 {
333         const char *ptr;
334         int eol = 0;
335
336         if (len == 0)
337                 return;
338
339         ptr  = buffer->text.ptr + buffer->current;
340         buffer->current += len;
341
342         if (ptr[len - 1] == '\n') {
343                 eol = 1;
344                 len--;
345         }
346
347         fputs(diff_get_color(1, color), stdout);
348         fwrite(ptr, len, 1, stdout);
349         fputs(diff_get_color(1, DIFF_RESET), stdout);
350
351         if (eol) {
352                 if (suppress_newline)
353                         buffer->suppressed_newline = 1;
354                 else
355                         putchar('\n');
356         }
357 }
358
359 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
360 {
361         struct diff_words_data *diff_words = priv;
362
363         if (diff_words->minus.suppressed_newline) {
364                 if (line[0] != '+')
365                         putchar('\n');
366                 diff_words->minus.suppressed_newline = 0;
367         }
368
369         len--;
370         switch (line[0]) {
371                 case '-':
372                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
373                         break;
374                 case '+':
375                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
376                         break;
377                 case ' ':
378                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
379                         diff_words->minus.current += len;
380                         break;
381         }
382 }
383
384 /* this executes the word diff on the accumulated buffers */
385 static void diff_words_show(struct diff_words_data *diff_words)
386 {
387         xpparam_t xpp;
388         xdemitconf_t xecfg;
389         xdemitcb_t ecb;
390         mmfile_t minus, plus;
391         int i;
392
393         minus.size = diff_words->minus.text.size;
394         minus.ptr = xmalloc(minus.size);
395         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
396         for (i = 0; i < minus.size; i++)
397                 if (isspace(minus.ptr[i]))
398                         minus.ptr[i] = '\n';
399         diff_words->minus.current = 0;
400
401         plus.size = diff_words->plus.text.size;
402         plus.ptr = xmalloc(plus.size);
403         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
404         for (i = 0; i < plus.size; i++)
405                 if (isspace(plus.ptr[i]))
406                         plus.ptr[i] = '\n';
407         diff_words->plus.current = 0;
408
409         xpp.flags = XDF_NEED_MINIMAL;
410         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
411         xecfg.flags = 0;
412         ecb.outf = xdiff_outf;
413         ecb.priv = diff_words;
414         diff_words->xm.consume = fn_out_diff_words_aux;
415         xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
416
417         free(minus.ptr);
418         free(plus.ptr);
419         diff_words->minus.text.size = diff_words->plus.text.size = 0;
420
421         if (diff_words->minus.suppressed_newline) {
422                 putchar('\n');
423                 diff_words->minus.suppressed_newline = 0;
424         }
425 }
426
427 struct emit_callback {
428         struct xdiff_emit_state xm;
429         int nparents, color_diff;
430         const char **label_path;
431         struct diff_words_data *diff_words;
432         int *found_changesp;
433 };
434
435 static void free_diff_words_data(struct emit_callback *ecbdata)
436 {
437         if (ecbdata->diff_words) {
438                 /* flush buffers */
439                 if (ecbdata->diff_words->minus.text.size ||
440                                 ecbdata->diff_words->plus.text.size)
441                         diff_words_show(ecbdata->diff_words);
442
443                 if (ecbdata->diff_words->minus.text.ptr)
444                         free (ecbdata->diff_words->minus.text.ptr);
445                 if (ecbdata->diff_words->plus.text.ptr)
446                         free (ecbdata->diff_words->plus.text.ptr);
447                 free(ecbdata->diff_words);
448                 ecbdata->diff_words = NULL;
449         }
450 }
451
452 const char *diff_get_color(int diff_use_color, enum color_diff ix)
453 {
454         if (diff_use_color)
455                 return diff_colors[ix];
456         return "";
457 }
458
459 static void emit_line(const char *set, const char *reset, const char *line, int len)
460 {
461         if (len > 0 && line[len-1] == '\n')
462                 len--;
463         fputs(set, stdout);
464         fwrite(line, len, 1, stdout);
465         puts(reset);
466 }
467
468 static void emit_line_with_ws(int nparents,
469                 const char *set, const char *reset, const char *ws,
470                 const char *line, int len)
471 {
472         int col0 = nparents;
473         int last_tab_in_indent = -1;
474         int last_space_in_indent = -1;
475         int i;
476         int tail = len;
477         int need_highlight_leading_space = 0;
478         /* The line is a newly added line.  Does it have funny leading
479          * whitespaces?  In indent, SP should never precede a TAB.
480          */
481         for (i = col0; i < len; i++) {
482                 if (line[i] == '\t') {
483                         last_tab_in_indent = i;
484                         if (0 <= last_space_in_indent)
485                                 need_highlight_leading_space = 1;
486                 }
487                 else if (line[i] == ' ')
488                         last_space_in_indent = i;
489                 else
490                         break;
491         }
492         fputs(set, stdout);
493         fwrite(line, col0, 1, stdout);
494         fputs(reset, stdout);
495         if (((i == len) || line[i] == '\n') && i != col0) {
496                 /* The whole line was indent */
497                 emit_line(ws, reset, line + col0, len - col0);
498                 return;
499         }
500         i = col0;
501         if (need_highlight_leading_space) {
502                 while (i < last_tab_in_indent) {
503                         if (line[i] == ' ') {
504                                 fputs(ws, stdout);
505                                 putchar(' ');
506                                 fputs(reset, stdout);
507                         }
508                         else
509                                 putchar(line[i]);
510                         i++;
511                 }
512         }
513         tail = len - 1;
514         if (line[tail] == '\n' && i < tail)
515                 tail--;
516         while (i < tail) {
517                 if (!isspace(line[tail]))
518                         break;
519                 tail--;
520         }
521         if ((i < tail && line[tail + 1] != '\n')) {
522                 /* This has whitespace between tail+1..len */
523                 fputs(set, stdout);
524                 fwrite(line + i, tail - i + 1, 1, stdout);
525                 fputs(reset, stdout);
526                 emit_line(ws, reset, line + tail + 1, len - tail - 1);
527         }
528         else
529                 emit_line(set, reset, line + i, len - i);
530 }
531
532 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
533 {
534         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
535         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
536
537         if (!*ws)
538                 emit_line(set, reset, line, len);
539         else
540                 emit_line_with_ws(ecbdata->nparents, set, reset, ws,
541                                 line, len);
542 }
543
544 static void fn_out_consume(void *priv, char *line, unsigned long len)
545 {
546         int i;
547         int color;
548         struct emit_callback *ecbdata = priv;
549         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
550         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
551
552         *(ecbdata->found_changesp) = 1;
553
554         if (ecbdata->label_path[0]) {
555                 const char *name_a_tab, *name_b_tab;
556
557                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
558                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
559
560                 printf("%s--- %s%s%s\n",
561                        set, ecbdata->label_path[0], reset, name_a_tab);
562                 printf("%s+++ %s%s%s\n",
563                        set, ecbdata->label_path[1], reset, name_b_tab);
564                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
565         }
566
567         /* This is not really necessary for now because
568          * this codepath only deals with two-way diffs.
569          */
570         for (i = 0; i < len && line[i] == '@'; i++)
571                 ;
572         if (2 <= i && i < len && line[i] == ' ') {
573                 ecbdata->nparents = i - 1;
574                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
575                           reset, line, len);
576                 return;
577         }
578
579         if (len < ecbdata->nparents) {
580                 set = reset;
581                 emit_line(reset, reset, line, len);
582                 return;
583         }
584
585         color = DIFF_PLAIN;
586         if (ecbdata->diff_words && ecbdata->nparents != 1)
587                 /* fall back to normal diff */
588                 free_diff_words_data(ecbdata);
589         if (ecbdata->diff_words) {
590                 if (line[0] == '-') {
591                         diff_words_append(line, len,
592                                           &ecbdata->diff_words->minus);
593                         return;
594                 } else if (line[0] == '+') {
595                         diff_words_append(line, len,
596                                           &ecbdata->diff_words->plus);
597                         return;
598                 }
599                 if (ecbdata->diff_words->minus.text.size ||
600                     ecbdata->diff_words->plus.text.size)
601                         diff_words_show(ecbdata->diff_words);
602                 line++;
603                 len--;
604                 emit_line(set, reset, line, len);
605                 return;
606         }
607         for (i = 0; i < ecbdata->nparents && len; i++) {
608                 if (line[i] == '-')
609                         color = DIFF_FILE_OLD;
610                 else if (line[i] == '+')
611                         color = DIFF_FILE_NEW;
612         }
613
614         if (color != DIFF_FILE_NEW) {
615                 emit_line(diff_get_color(ecbdata->color_diff, color),
616                           reset, line, len);
617                 return;
618         }
619         emit_add_line(reset, ecbdata, line, len);
620 }
621
622 static char *pprint_rename(const char *a, const char *b)
623 {
624         const char *old = a;
625         const char *new = b;
626         char *name = NULL;
627         int pfx_length, sfx_length;
628         int len_a = strlen(a);
629         int len_b = strlen(b);
630         int qlen_a = quote_c_style(a, NULL, NULL, 0);
631         int qlen_b = quote_c_style(b, NULL, NULL, 0);
632
633         if (qlen_a || qlen_b) {
634                 if (qlen_a) len_a = qlen_a;
635                 if (qlen_b) len_b = qlen_b;
636                 name = xmalloc( len_a + len_b + 5 );
637                 if (qlen_a)
638                         quote_c_style(a, name, NULL, 0);
639                 else
640                         memcpy(name, a, len_a);
641                 memcpy(name + len_a, " => ", 4);
642                 if (qlen_b)
643                         quote_c_style(b, name + len_a + 4, NULL, 0);
644                 else
645                         memcpy(name + len_a + 4, b, len_b + 1);
646                 return name;
647         }
648
649         /* Find common prefix */
650         pfx_length = 0;
651         while (*old && *new && *old == *new) {
652                 if (*old == '/')
653                         pfx_length = old - a + 1;
654                 old++;
655                 new++;
656         }
657
658         /* Find common suffix */
659         old = a + len_a;
660         new = b + len_b;
661         sfx_length = 0;
662         while (a <= old && b <= new && *old == *new) {
663                 if (*old == '/')
664                         sfx_length = len_a - (old - a);
665                 old--;
666                 new--;
667         }
668
669         /*
670          * pfx{mid-a => mid-b}sfx
671          * {pfx-a => pfx-b}sfx
672          * pfx{sfx-a => sfx-b}
673          * name-a => name-b
674          */
675         if (pfx_length + sfx_length) {
676                 int a_midlen = len_a - pfx_length - sfx_length;
677                 int b_midlen = len_b - pfx_length - sfx_length;
678                 if (a_midlen < 0) a_midlen = 0;
679                 if (b_midlen < 0) b_midlen = 0;
680
681                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
682                 sprintf(name, "%.*s{%.*s => %.*s}%s",
683                         pfx_length, a,
684                         a_midlen, a + pfx_length,
685                         b_midlen, b + pfx_length,
686                         a + len_a - sfx_length);
687         }
688         else {
689                 name = xmalloc(len_a + len_b + 5);
690                 sprintf(name, "%s => %s", a, b);
691         }
692         return name;
693 }
694
695 struct diffstat_t {
696         struct xdiff_emit_state xm;
697
698         int nr;
699         int alloc;
700         struct diffstat_file {
701                 char *name;
702                 unsigned is_unmerged:1;
703                 unsigned is_binary:1;
704                 unsigned is_renamed:1;
705                 unsigned int added, deleted;
706         } **files;
707 };
708
709 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
710                                           const char *name_a,
711                                           const char *name_b)
712 {
713         struct diffstat_file *x;
714         x = xcalloc(sizeof (*x), 1);
715         if (diffstat->nr == diffstat->alloc) {
716                 diffstat->alloc = alloc_nr(diffstat->alloc);
717                 diffstat->files = xrealloc(diffstat->files,
718                                 diffstat->alloc * sizeof(x));
719         }
720         diffstat->files[diffstat->nr++] = x;
721         if (name_b) {
722                 x->name = pprint_rename(name_a, name_b);
723                 x->is_renamed = 1;
724         }
725         else
726                 x->name = xstrdup(name_a);
727         return x;
728 }
729
730 static void diffstat_consume(void *priv, char *line, unsigned long len)
731 {
732         struct diffstat_t *diffstat = priv;
733         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
734
735         if (line[0] == '+')
736                 x->added++;
737         else if (line[0] == '-')
738                 x->deleted++;
739 }
740
741 const char mime_boundary_leader[] = "------------";
742
743 static int scale_linear(int it, int width, int max_change)
744 {
745         /*
746          * make sure that at least one '-' is printed if there were deletions,
747          * and likewise for '+'.
748          */
749         if (max_change < 2)
750                 return it;
751         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
752 }
753
754 static void show_name(const char *prefix, const char *name, int len,
755                       const char *reset, const char *set)
756 {
757         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
758 }
759
760 static void show_graph(char ch, int cnt, const char *set, const char *reset)
761 {
762         if (cnt <= 0)
763                 return;
764         printf("%s", set);
765         while (cnt--)
766                 putchar(ch);
767         printf("%s", reset);
768 }
769
770 static void show_stats(struct diffstat_t* data, struct diff_options *options)
771 {
772         int i, len, add, del, total, adds = 0, dels = 0;
773         int max_change = 0, max_len = 0;
774         int total_files = data->nr;
775         int width, name_width;
776         const char *reset, *set, *add_c, *del_c;
777
778         if (data->nr == 0)
779                 return;
780
781         width = options->stat_width ? options->stat_width : 80;
782         name_width = options->stat_name_width ? options->stat_name_width : 50;
783
784         /* Sanity: give at least 5 columns to the graph,
785          * but leave at least 10 columns for the name.
786          */
787         if (width < name_width + 15) {
788                 if (name_width <= 25)
789                         width = name_width + 15;
790                 else
791                         name_width = width - 15;
792         }
793
794         /* Find the longest filename and max number of changes */
795         reset = diff_get_color(options->color_diff, DIFF_RESET);
796         set = diff_get_color(options->color_diff, DIFF_PLAIN);
797         add_c = diff_get_color(options->color_diff, DIFF_FILE_NEW);
798         del_c = diff_get_color(options->color_diff, DIFF_FILE_OLD);
799
800         for (i = 0; i < data->nr; i++) {
801                 struct diffstat_file *file = data->files[i];
802                 int change = file->added + file->deleted;
803
804                 if (!file->is_renamed) {  /* renames are already quoted by pprint_rename */
805                         len = quote_c_style(file->name, NULL, NULL, 0);
806                         if (len) {
807                                 char *qname = xmalloc(len + 1);
808                                 quote_c_style(file->name, qname, NULL, 0);
809                                 free(file->name);
810                                 file->name = qname;
811                         }
812                 }
813
814                 len = strlen(file->name);
815                 if (max_len < len)
816                         max_len = len;
817
818                 if (file->is_binary || file->is_unmerged)
819                         continue;
820                 if (max_change < change)
821                         max_change = change;
822         }
823
824         /* Compute the width of the graph part;
825          * 10 is for one blank at the beginning of the line plus
826          * " | count " between the name and the graph.
827          *
828          * From here on, name_width is the width of the name area,
829          * and width is the width of the graph area.
830          */
831         name_width = (name_width < max_len) ? name_width : max_len;
832         if (width < (name_width + 10) + max_change)
833                 width = width - (name_width + 10);
834         else
835                 width = max_change;
836
837         for (i = 0; i < data->nr; i++) {
838                 const char *prefix = "";
839                 char *name = data->files[i]->name;
840                 int added = data->files[i]->added;
841                 int deleted = data->files[i]->deleted;
842                 int name_len;
843
844                 /*
845                  * "scale" the filename
846                  */
847                 len = name_width;
848                 name_len = strlen(name);
849                 if (name_width < name_len) {
850                         char *slash;
851                         prefix = "...";
852                         len -= 3;
853                         name += name_len - len;
854                         slash = strchr(name, '/');
855                         if (slash)
856                                 name = slash;
857                 }
858
859                 if (data->files[i]->is_binary) {
860                         show_name(prefix, name, len, reset, set);
861                         printf("  Bin ");
862                         printf("%s%d%s", del_c, deleted, reset);
863                         printf(" -> ");
864                         printf("%s%d%s", add_c, added, reset);
865                         printf(" bytes");
866                         printf("\n");
867                         goto free_diffstat_file;
868                 }
869                 else if (data->files[i]->is_unmerged) {
870                         show_name(prefix, name, len, reset, set);
871                         printf("  Unmerged\n");
872                         goto free_diffstat_file;
873                 }
874                 else if (!data->files[i]->is_renamed &&
875                          (added + deleted == 0)) {
876                         total_files--;
877                         goto free_diffstat_file;
878                 }
879
880                 /*
881                  * scale the add/delete
882                  */
883                 add = added;
884                 del = deleted;
885                 total = add + del;
886                 adds += add;
887                 dels += del;
888
889                 if (width <= max_change) {
890                         add = scale_linear(add, width, max_change);
891                         del = scale_linear(del, width, max_change);
892                         total = add + del;
893                 }
894                 show_name(prefix, name, len, reset, set);
895                 printf("%5d ", added + deleted);
896                 show_graph('+', add, add_c, reset);
897                 show_graph('-', del, del_c, reset);
898                 putchar('\n');
899         free_diffstat_file:
900                 free(data->files[i]->name);
901                 free(data->files[i]);
902         }
903         free(data->files);
904         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
905                set, total_files, adds, dels, reset);
906 }
907
908 static void show_shortstats(struct diffstat_t* data)
909 {
910         int i, adds = 0, dels = 0, total_files = data->nr;
911
912         if (data->nr == 0)
913                 return;
914
915         for (i = 0; i < data->nr; i++) {
916                 if (!data->files[i]->is_binary &&
917                     !data->files[i]->is_unmerged) {
918                         int added = data->files[i]->added;
919                         int deleted= data->files[i]->deleted;
920                         if (!data->files[i]->is_renamed &&
921                             (added + deleted == 0)) {
922                                 total_files--;
923                         } else {
924                                 adds += added;
925                                 dels += deleted;
926                         }
927                 }
928                 free(data->files[i]->name);
929                 free(data->files[i]);
930         }
931         free(data->files);
932
933         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
934                total_files, adds, dels);
935 }
936
937 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
938 {
939         int i;
940
941         for (i = 0; i < data->nr; i++) {
942                 struct diffstat_file *file = data->files[i];
943
944                 if (file->is_binary)
945                         printf("-\t-\t");
946                 else
947                         printf("%d\t%d\t", file->added, file->deleted);
948                 if (options->line_termination && !file->is_renamed &&
949                     quote_c_style(file->name, NULL, NULL, 0))
950                         quote_c_style(file->name, NULL, stdout, 0);
951                 else
952                         fputs(file->name, stdout);
953                 putchar(options->line_termination);
954         }
955 }
956
957 struct checkdiff_t {
958         struct xdiff_emit_state xm;
959         const char *filename;
960         int lineno, color_diff;
961 };
962
963 static void checkdiff_consume(void *priv, char *line, unsigned long len)
964 {
965         struct checkdiff_t *data = priv;
966         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
967         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
968         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
969
970         if (line[0] == '+') {
971                 int i, spaces = 0, space_before_tab = 0, white_space_at_end = 0;
972
973                 /* check space before tab */
974                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
975                         if (line[i] == ' ')
976                                 spaces++;
977                 if (line[i - 1] == '\t' && spaces)
978                         space_before_tab = 1;
979
980                 /* check white space at line end */
981                 if (line[len - 1] == '\n')
982                         len--;
983                 if (isspace(line[len - 1]))
984                         white_space_at_end = 1;
985
986                 if (space_before_tab || white_space_at_end) {
987                         printf("%s:%d: %s", data->filename, data->lineno, ws);
988                         if (space_before_tab) {
989                                 printf("space before tab");
990                                 if (white_space_at_end)
991                                         putchar(',');
992                         }
993                         if (white_space_at_end)
994                                 printf("white space at end");
995                         printf(":%s ", reset);
996                         emit_line_with_ws(1, set, reset, ws, line, len);
997                 }
998
999                 data->lineno++;
1000         } else if (line[0] == ' ')
1001                 data->lineno++;
1002         else if (line[0] == '@') {
1003                 char *plus = strchr(line, '+');
1004                 if (plus)
1005                         data->lineno = strtol(plus, NULL, 10);
1006                 else
1007                         die("invalid diff");
1008         }
1009 }
1010
1011 static unsigned char *deflate_it(char *data,
1012                                  unsigned long size,
1013                                  unsigned long *result_size)
1014 {
1015         int bound;
1016         unsigned char *deflated;
1017         z_stream stream;
1018
1019         memset(&stream, 0, sizeof(stream));
1020         deflateInit(&stream, zlib_compression_level);
1021         bound = deflateBound(&stream, size);
1022         deflated = xmalloc(bound);
1023         stream.next_out = deflated;
1024         stream.avail_out = bound;
1025
1026         stream.next_in = (unsigned char *)data;
1027         stream.avail_in = size;
1028         while (deflate(&stream, Z_FINISH) == Z_OK)
1029                 ; /* nothing */
1030         deflateEnd(&stream);
1031         *result_size = stream.total_out;
1032         return deflated;
1033 }
1034
1035 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
1036 {
1037         void *cp;
1038         void *delta;
1039         void *deflated;
1040         void *data;
1041         unsigned long orig_size;
1042         unsigned long delta_size;
1043         unsigned long deflate_size;
1044         unsigned long data_size;
1045
1046         /* We could do deflated delta, or we could do just deflated two,
1047          * whichever is smaller.
1048          */
1049         delta = NULL;
1050         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1051         if (one->size && two->size) {
1052                 delta = diff_delta(one->ptr, one->size,
1053                                    two->ptr, two->size,
1054                                    &delta_size, deflate_size);
1055                 if (delta) {
1056                         void *to_free = delta;
1057                         orig_size = delta_size;
1058                         delta = deflate_it(delta, delta_size, &delta_size);
1059                         free(to_free);
1060                 }
1061         }
1062
1063         if (delta && delta_size < deflate_size) {
1064                 printf("delta %lu\n", orig_size);
1065                 free(deflated);
1066                 data = delta;
1067                 data_size = delta_size;
1068         }
1069         else {
1070                 printf("literal %lu\n", two->size);
1071                 free(delta);
1072                 data = deflated;
1073                 data_size = deflate_size;
1074         }
1075
1076         /* emit data encoded in base85 */
1077         cp = data;
1078         while (data_size) {
1079                 int bytes = (52 < data_size) ? 52 : data_size;
1080                 char line[70];
1081                 data_size -= bytes;
1082                 if (bytes <= 26)
1083                         line[0] = bytes + 'A' - 1;
1084                 else
1085                         line[0] = bytes - 26 + 'a' - 1;
1086                 encode_85(line + 1, cp, bytes);
1087                 cp = (char *) cp + bytes;
1088                 puts(line);
1089         }
1090         printf("\n");
1091         free(data);
1092 }
1093
1094 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1095 {
1096         printf("GIT binary patch\n");
1097         emit_binary_diff_body(one, two);
1098         emit_binary_diff_body(two, one);
1099 }
1100
1101 static void setup_diff_attr_check(struct git_attr_check *check)
1102 {
1103         static struct git_attr *attr_diff;
1104
1105         if (!attr_diff)
1106                 attr_diff = git_attr("diff", 4);
1107         check->attr = attr_diff;
1108 }
1109
1110 static int file_is_binary(struct diff_filespec *one)
1111 {
1112         struct git_attr_check attr_diff_check;
1113
1114         setup_diff_attr_check(&attr_diff_check);
1115         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1116                 const char *value = attr_diff_check.value;
1117                 if (ATTR_TRUE(value))
1118                         return 0;
1119                 else if (ATTR_FALSE(value))
1120                         return 1;
1121         }
1122
1123         if (!one->data) {
1124                 if (!DIFF_FILE_VALID(one))
1125                         return 0;
1126                 diff_populate_filespec(one, 0);
1127         }
1128         return buffer_is_binary(one->data, one->size);
1129 }
1130
1131 static void builtin_diff(const char *name_a,
1132                          const char *name_b,
1133                          struct diff_filespec *one,
1134                          struct diff_filespec *two,
1135                          const char *xfrm_msg,
1136                          struct diff_options *o,
1137                          int complete_rewrite)
1138 {
1139         mmfile_t mf1, mf2;
1140         const char *lbl[2];
1141         char *a_one, *b_two;
1142         const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
1143         const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
1144
1145         a_one = quote_two("a/", name_a + (*name_a == '/'));
1146         b_two = quote_two("b/", name_b + (*name_b == '/'));
1147         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1148         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1149         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1150         if (lbl[0][0] == '/') {
1151                 /* /dev/null */
1152                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1153                 if (xfrm_msg && xfrm_msg[0])
1154                         printf("%s%s%s\n", set, xfrm_msg, reset);
1155         }
1156         else if (lbl[1][0] == '/') {
1157                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1158                 if (xfrm_msg && xfrm_msg[0])
1159                         printf("%s%s%s\n", set, xfrm_msg, reset);
1160         }
1161         else {
1162                 if (one->mode != two->mode) {
1163                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1164                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1165                 }
1166                 if (xfrm_msg && xfrm_msg[0])
1167                         printf("%s%s%s\n", set, xfrm_msg, reset);
1168                 /*
1169                  * we do not run diff between different kind
1170                  * of objects.
1171                  */
1172                 if ((one->mode ^ two->mode) & S_IFMT)
1173                         goto free_ab_and_return;
1174                 if (complete_rewrite) {
1175                         emit_rewrite_diff(name_a, name_b, one, two,
1176                                         o->color_diff);
1177                         o->found_changes = 1;
1178                         goto free_ab_and_return;
1179                 }
1180         }
1181
1182         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1183                 die("unable to read files to diff");
1184
1185         if (!o->text && (file_is_binary(one) || file_is_binary(two))) {
1186                 /* Quite common confusing case */
1187                 if (mf1.size == mf2.size &&
1188                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1189                         goto free_ab_and_return;
1190                 if (o->binary)
1191                         emit_binary_diff(&mf1, &mf2);
1192                 else
1193                         printf("Binary files %s and %s differ\n",
1194                                lbl[0], lbl[1]);
1195                 o->found_changes = 1;
1196         }
1197         else {
1198                 /* Crazy xdl interfaces.. */
1199                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1200                 xpparam_t xpp;
1201                 xdemitconf_t xecfg;
1202                 xdemitcb_t ecb;
1203                 struct emit_callback ecbdata;
1204
1205                 memset(&ecbdata, 0, sizeof(ecbdata));
1206                 ecbdata.label_path = lbl;
1207                 ecbdata.color_diff = o->color_diff;
1208                 ecbdata.found_changesp = &o->found_changes;
1209                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1210                 xecfg.ctxlen = o->context;
1211                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1212                 if (!diffopts)
1213                         ;
1214                 else if (!prefixcmp(diffopts, "--unified="))
1215                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1216                 else if (!prefixcmp(diffopts, "-u"))
1217                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1218                 ecb.outf = xdiff_outf;
1219                 ecb.priv = &ecbdata;
1220                 ecbdata.xm.consume = fn_out_consume;
1221                 if (o->color_diff_words)
1222                         ecbdata.diff_words =
1223                                 xcalloc(1, sizeof(struct diff_words_data));
1224                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1225                 if (o->color_diff_words)
1226                         free_diff_words_data(&ecbdata);
1227         }
1228
1229  free_ab_and_return:
1230         diff_free_filespec_data(one);
1231         diff_free_filespec_data(two);
1232         free(a_one);
1233         free(b_two);
1234         return;
1235 }
1236
1237 static void builtin_diffstat(const char *name_a, const char *name_b,
1238                              struct diff_filespec *one,
1239                              struct diff_filespec *two,
1240                              struct diffstat_t *diffstat,
1241                              struct diff_options *o,
1242                              int complete_rewrite)
1243 {
1244         mmfile_t mf1, mf2;
1245         struct diffstat_file *data;
1246
1247         data = diffstat_add(diffstat, name_a, name_b);
1248
1249         if (!one || !two) {
1250                 data->is_unmerged = 1;
1251                 return;
1252         }
1253         if (complete_rewrite) {
1254                 diff_populate_filespec(one, 0);
1255                 diff_populate_filespec(two, 0);
1256                 data->deleted = count_lines(one->data, one->size);
1257                 data->added = count_lines(two->data, two->size);
1258                 goto free_and_return;
1259         }
1260         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1261                 die("unable to read files to diff");
1262
1263         if (file_is_binary(one) || file_is_binary(two)) {
1264                 data->is_binary = 1;
1265                 data->added = mf2.size;
1266                 data->deleted = mf1.size;
1267         } else {
1268                 /* Crazy xdl interfaces.. */
1269                 xpparam_t xpp;
1270                 xdemitconf_t xecfg;
1271                 xdemitcb_t ecb;
1272
1273                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1274                 xecfg.ctxlen = 0;
1275                 xecfg.flags = 0;
1276                 ecb.outf = xdiff_outf;
1277                 ecb.priv = diffstat;
1278                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1279         }
1280
1281  free_and_return:
1282         diff_free_filespec_data(one);
1283         diff_free_filespec_data(two);
1284 }
1285
1286 static void builtin_checkdiff(const char *name_a, const char *name_b,
1287                              struct diff_filespec *one,
1288                              struct diff_filespec *two, struct diff_options *o)
1289 {
1290         mmfile_t mf1, mf2;
1291         struct checkdiff_t data;
1292
1293         if (!two)
1294                 return;
1295
1296         memset(&data, 0, sizeof(data));
1297         data.xm.consume = checkdiff_consume;
1298         data.filename = name_b ? name_b : name_a;
1299         data.lineno = 0;
1300         data.color_diff = o->color_diff;
1301
1302         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1303                 die("unable to read files to diff");
1304
1305         if (file_is_binary(two))
1306                 goto free_and_return;
1307         else {
1308                 /* Crazy xdl interfaces.. */
1309                 xpparam_t xpp;
1310                 xdemitconf_t xecfg;
1311                 xdemitcb_t ecb;
1312
1313                 xpp.flags = XDF_NEED_MINIMAL;
1314                 xecfg.ctxlen = 0;
1315                 xecfg.flags = 0;
1316                 ecb.outf = xdiff_outf;
1317                 ecb.priv = &data;
1318                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1319         }
1320  free_and_return:
1321         diff_free_filespec_data(one);
1322         diff_free_filespec_data(two);
1323 }
1324
1325 struct diff_filespec *alloc_filespec(const char *path)
1326 {
1327         int namelen = strlen(path);
1328         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1329
1330         memset(spec, 0, sizeof(*spec));
1331         spec->path = (char *)(spec + 1);
1332         memcpy(spec->path, path, namelen+1);
1333         return spec;
1334 }
1335
1336 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1337                    unsigned short mode)
1338 {
1339         if (mode) {
1340                 spec->mode = canon_mode(mode);
1341                 hashcpy(spec->sha1, sha1);
1342                 spec->sha1_valid = !is_null_sha1(sha1);
1343         }
1344 }
1345
1346 /*
1347  * Given a name and sha1 pair, if the index tells us the file in
1348  * the work tree has that object contents, return true, so that
1349  * prepare_temp_file() does not have to inflate and extract.
1350  */
1351 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1352 {
1353         struct cache_entry *ce;
1354         struct stat st;
1355         int pos, len;
1356
1357         /* We do not read the cache ourselves here, because the
1358          * benchmark with my previous version that always reads cache
1359          * shows that it makes things worse for diff-tree comparing
1360          * two linux-2.6 kernel trees in an already checked out work
1361          * tree.  This is because most diff-tree comparisons deal with
1362          * only a small number of files, while reading the cache is
1363          * expensive for a large project, and its cost outweighs the
1364          * savings we get by not inflating the object to a temporary
1365          * file.  Practically, this code only helps when we are used
1366          * by diff-cache --cached, which does read the cache before
1367          * calling us.
1368          */
1369         if (!active_cache)
1370                 return 0;
1371
1372         /* We want to avoid the working directory if our caller
1373          * doesn't need the data in a normal file, this system
1374          * is rather slow with its stat/open/mmap/close syscalls,
1375          * and the object is contained in a pack file.  The pack
1376          * is probably already open and will be faster to obtain
1377          * the data through than the working directory.  Loose
1378          * objects however would tend to be slower as they need
1379          * to be individually opened and inflated.
1380          */
1381         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1382                 return 0;
1383
1384         len = strlen(name);
1385         pos = cache_name_pos(name, len);
1386         if (pos < 0)
1387                 return 0;
1388         ce = active_cache[pos];
1389         if ((lstat(name, &st) < 0) ||
1390             !S_ISREG(st.st_mode) || /* careful! */
1391             ce_match_stat(ce, &st, 0) ||
1392             hashcmp(sha1, ce->sha1))
1393                 return 0;
1394         /* we return 1 only when we can stat, it is a regular file,
1395          * stat information matches, and sha1 recorded in the cache
1396          * matches.  I.e. we know the file in the work tree really is
1397          * the same as the <name, sha1> pair.
1398          */
1399         return 1;
1400 }
1401
1402 static int populate_from_stdin(struct diff_filespec *s)
1403 {
1404 #define INCREMENT 1024
1405         char *buf;
1406         unsigned long size;
1407         ssize_t got;
1408
1409         size = 0;
1410         buf = NULL;
1411         while (1) {
1412                 buf = xrealloc(buf, size + INCREMENT);
1413                 got = xread(0, buf + size, INCREMENT);
1414                 if (!got)
1415                         break; /* EOF */
1416                 if (got < 0)
1417                         return error("error while reading from stdin %s",
1418                                      strerror(errno));
1419                 size += got;
1420         }
1421         s->should_munmap = 0;
1422         s->data = buf;
1423         s->size = size;
1424         s->should_free = 1;
1425         return 0;
1426 }
1427
1428 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1429 {
1430         int len;
1431         char *data = xmalloc(100);
1432         len = snprintf(data, 100,
1433                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1434         s->data = data;
1435         s->size = len;
1436         s->should_free = 1;
1437         if (size_only) {
1438                 s->data = NULL;
1439                 free(data);
1440         }
1441         return 0;
1442 }
1443
1444 /*
1445  * While doing rename detection and pickaxe operation, we may need to
1446  * grab the data for the blob (or file) for our own in-core comparison.
1447  * diff_filespec has data and size fields for this purpose.
1448  */
1449 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1450 {
1451         int err = 0;
1452         if (!DIFF_FILE_VALID(s))
1453                 die("internal error: asking to populate invalid file.");
1454         if (S_ISDIR(s->mode))
1455                 return -1;
1456
1457         if (s->data)
1458                 return 0;
1459
1460         if (size_only && 0 < s->size)
1461                 return 0;
1462
1463         if (S_ISGITLINK(s->mode))
1464                 return diff_populate_gitlink(s, size_only);
1465
1466         if (!s->sha1_valid ||
1467             reuse_worktree_file(s->path, s->sha1, 0)) {
1468                 struct stat st;
1469                 int fd;
1470                 char *buf;
1471                 unsigned long size;
1472
1473                 if (!strcmp(s->path, "-"))
1474                         return populate_from_stdin(s);
1475
1476                 if (lstat(s->path, &st) < 0) {
1477                         if (errno == ENOENT) {
1478                         err_empty:
1479                                 err = -1;
1480                         empty:
1481                                 s->data = (char *)"";
1482                                 s->size = 0;
1483                                 return err;
1484                         }
1485                 }
1486                 s->size = xsize_t(st.st_size);
1487                 if (!s->size)
1488                         goto empty;
1489                 if (size_only)
1490                         return 0;
1491                 if (S_ISLNK(st.st_mode)) {
1492                         int ret;
1493                         s->data = xmalloc(s->size);
1494                         s->should_free = 1;
1495                         ret = readlink(s->path, s->data, s->size);
1496                         if (ret < 0) {
1497                                 free(s->data);
1498                                 goto err_empty;
1499                         }
1500                         return 0;
1501                 }
1502                 fd = open(s->path, O_RDONLY);
1503                 if (fd < 0)
1504                         goto err_empty;
1505                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1506                 close(fd);
1507                 s->should_munmap = 1;
1508
1509                 /*
1510                  * Convert from working tree format to canonical git format
1511                  */
1512                 size = s->size;
1513                 buf = convert_to_git(s->path, s->data, &size);
1514                 if (buf) {
1515                         munmap(s->data, s->size);
1516                         s->should_munmap = 0;
1517                         s->data = buf;
1518                         s->size = size;
1519                         s->should_free = 1;
1520                 }
1521         }
1522         else {
1523                 enum object_type type;
1524                 if (size_only)
1525                         type = sha1_object_info(s->sha1, &s->size);
1526                 else {
1527                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1528                         s->should_free = 1;
1529                 }
1530         }
1531         return 0;
1532 }
1533
1534 void diff_free_filespec_data(struct diff_filespec *s)
1535 {
1536         if (s->should_free)
1537                 free(s->data);
1538         else if (s->should_munmap)
1539                 munmap(s->data, s->size);
1540
1541         if (s->should_free || s->should_munmap) {
1542                 s->should_free = s->should_munmap = 0;
1543                 s->data = NULL;
1544         }
1545         free(s->cnt_data);
1546         s->cnt_data = NULL;
1547 }
1548
1549 static void prep_temp_blob(struct diff_tempfile *temp,
1550                            void *blob,
1551                            unsigned long size,
1552                            const unsigned char *sha1,
1553                            int mode)
1554 {
1555         int fd;
1556
1557         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1558         if (fd < 0)
1559                 die("unable to create temp-file");
1560         if (write_in_full(fd, blob, size) != size)
1561                 die("unable to write temp-file");
1562         close(fd);
1563         temp->name = temp->tmp_path;
1564         strcpy(temp->hex, sha1_to_hex(sha1));
1565         temp->hex[40] = 0;
1566         sprintf(temp->mode, "%06o", mode);
1567 }
1568
1569 static void prepare_temp_file(const char *name,
1570                               struct diff_tempfile *temp,
1571                               struct diff_filespec *one)
1572 {
1573         if (!DIFF_FILE_VALID(one)) {
1574         not_a_valid_file:
1575                 /* A '-' entry produces this for file-2, and
1576                  * a '+' entry produces this for file-1.
1577                  */
1578                 temp->name = "/dev/null";
1579                 strcpy(temp->hex, ".");
1580                 strcpy(temp->mode, ".");
1581                 return;
1582         }
1583
1584         if (!one->sha1_valid ||
1585             reuse_worktree_file(name, one->sha1, 1)) {
1586                 struct stat st;
1587                 if (lstat(name, &st) < 0) {
1588                         if (errno == ENOENT)
1589                                 goto not_a_valid_file;
1590                         die("stat(%s): %s", name, strerror(errno));
1591                 }
1592                 if (S_ISLNK(st.st_mode)) {
1593                         int ret;
1594                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1595                         size_t sz = xsize_t(st.st_size);
1596                         if (sizeof(buf) <= st.st_size)
1597                                 die("symlink too long: %s", name);
1598                         ret = readlink(name, buf, sz);
1599                         if (ret < 0)
1600                                 die("readlink(%s)", name);
1601                         prep_temp_blob(temp, buf, sz,
1602                                        (one->sha1_valid ?
1603                                         one->sha1 : null_sha1),
1604                                        (one->sha1_valid ?
1605                                         one->mode : S_IFLNK));
1606                 }
1607                 else {
1608                         /* we can borrow from the file in the work tree */
1609                         temp->name = name;
1610                         if (!one->sha1_valid)
1611                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1612                         else
1613                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1614                         /* Even though we may sometimes borrow the
1615                          * contents from the work tree, we always want
1616                          * one->mode.  mode is trustworthy even when
1617                          * !(one->sha1_valid), as long as
1618                          * DIFF_FILE_VALID(one).
1619                          */
1620                         sprintf(temp->mode, "%06o", one->mode);
1621                 }
1622                 return;
1623         }
1624         else {
1625                 if (diff_populate_filespec(one, 0))
1626                         die("cannot read data blob for %s", one->path);
1627                 prep_temp_blob(temp, one->data, one->size,
1628                                one->sha1, one->mode);
1629         }
1630 }
1631
1632 static void remove_tempfile(void)
1633 {
1634         int i;
1635
1636         for (i = 0; i < 2; i++)
1637                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1638                         unlink(diff_temp[i].name);
1639                         diff_temp[i].name = NULL;
1640                 }
1641 }
1642
1643 static void remove_tempfile_on_signal(int signo)
1644 {
1645         remove_tempfile();
1646         signal(SIGINT, SIG_DFL);
1647         raise(signo);
1648 }
1649
1650 static int spawn_prog(const char *pgm, const char **arg)
1651 {
1652         pid_t pid;
1653         int status;
1654
1655         fflush(NULL);
1656         pid = fork();
1657         if (pid < 0)
1658                 die("unable to fork");
1659         if (!pid) {
1660                 execvp(pgm, (char *const*) arg);
1661                 exit(255);
1662         }
1663
1664         while (waitpid(pid, &status, 0) < 0) {
1665                 if (errno == EINTR)
1666                         continue;
1667                 return -1;
1668         }
1669
1670         /* Earlier we did not check the exit status because
1671          * diff exits non-zero if files are different, and
1672          * we are not interested in knowing that.  It was a
1673          * mistake which made it harder to quit a diff-*
1674          * session that uses the git-apply-patch-script as
1675          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1676          * should also exit non-zero only when it wants to
1677          * abort the entire diff-* session.
1678          */
1679         if (WIFEXITED(status) && !WEXITSTATUS(status))
1680                 return 0;
1681         return -1;
1682 }
1683
1684 /* An external diff command takes:
1685  *
1686  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1687  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1688  *
1689  */
1690 static void run_external_diff(const char *pgm,
1691                               const char *name,
1692                               const char *other,
1693                               struct diff_filespec *one,
1694                               struct diff_filespec *two,
1695                               const char *xfrm_msg,
1696                               int complete_rewrite)
1697 {
1698         const char *spawn_arg[10];
1699         struct diff_tempfile *temp = diff_temp;
1700         int retval;
1701         static int atexit_asked = 0;
1702         const char *othername;
1703         const char **arg = &spawn_arg[0];
1704
1705         othername = (other? other : name);
1706         if (one && two) {
1707                 prepare_temp_file(name, &temp[0], one);
1708                 prepare_temp_file(othername, &temp[1], two);
1709                 if (! atexit_asked &&
1710                     (temp[0].name == temp[0].tmp_path ||
1711                      temp[1].name == temp[1].tmp_path)) {
1712                         atexit_asked = 1;
1713                         atexit(remove_tempfile);
1714                 }
1715                 signal(SIGINT, remove_tempfile_on_signal);
1716         }
1717
1718         if (one && two) {
1719                 *arg++ = pgm;
1720                 *arg++ = name;
1721                 *arg++ = temp[0].name;
1722                 *arg++ = temp[0].hex;
1723                 *arg++ = temp[0].mode;
1724                 *arg++ = temp[1].name;
1725                 *arg++ = temp[1].hex;
1726                 *arg++ = temp[1].mode;
1727                 if (other) {
1728                         *arg++ = other;
1729                         *arg++ = xfrm_msg;
1730                 }
1731         } else {
1732                 *arg++ = pgm;
1733                 *arg++ = name;
1734         }
1735         *arg = NULL;
1736         retval = spawn_prog(pgm, spawn_arg);
1737         remove_tempfile();
1738         if (retval) {
1739                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1740                 exit(1);
1741         }
1742 }
1743
1744 static const char *external_diff_attr(const char *name)
1745 {
1746         struct git_attr_check attr_diff_check;
1747
1748         setup_diff_attr_check(&attr_diff_check);
1749         if (!git_checkattr(name, 1, &attr_diff_check)) {
1750                 const char *value = attr_diff_check.value;
1751                 if (!ATTR_TRUE(value) &&
1752                     !ATTR_FALSE(value) &&
1753                     !ATTR_UNSET(value)) {
1754                         struct ll_diff_driver *drv;
1755
1756                         if (!user_diff_tail) {
1757                                 user_diff_tail = &user_diff;
1758                                 git_config(git_diff_ui_config);
1759                         }
1760                         for (drv = user_diff; drv; drv = drv->next)
1761                                 if (!strcmp(drv->name, value))
1762                                         return drv->cmd;
1763                 }
1764         }
1765         return NULL;
1766 }
1767
1768 static void run_diff_cmd(const char *pgm,
1769                          const char *name,
1770                          const char *other,
1771                          struct diff_filespec *one,
1772                          struct diff_filespec *two,
1773                          const char *xfrm_msg,
1774                          struct diff_options *o,
1775                          int complete_rewrite)
1776 {
1777         if (!o->allow_external)
1778                 pgm = NULL;
1779         else {
1780                 const char *cmd = external_diff_attr(name);
1781                 if (cmd)
1782                         pgm = cmd;
1783         }
1784
1785         if (pgm) {
1786                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1787                                   complete_rewrite);
1788                 return;
1789         }
1790         if (one && two)
1791                 builtin_diff(name, other ? other : name,
1792                              one, two, xfrm_msg, o, complete_rewrite);
1793         else
1794                 printf("* Unmerged path %s\n", name);
1795 }
1796
1797 static void diff_fill_sha1_info(struct diff_filespec *one)
1798 {
1799         if (DIFF_FILE_VALID(one)) {
1800                 if (!one->sha1_valid) {
1801                         struct stat st;
1802                         if (!strcmp(one->path, "-")) {
1803                                 hashcpy(one->sha1, null_sha1);
1804                                 return;
1805                         }
1806                         if (lstat(one->path, &st) < 0)
1807                                 die("stat %s", one->path);
1808                         if (index_path(one->sha1, one->path, &st, 0))
1809                                 die("cannot hash %s\n", one->path);
1810                 }
1811         }
1812         else
1813                 hashclr(one->sha1);
1814 }
1815
1816 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1817 {
1818         const char *pgm = external_diff();
1819         char msg[PATH_MAX*2+300], *xfrm_msg;
1820         struct diff_filespec *one;
1821         struct diff_filespec *two;
1822         const char *name;
1823         const char *other;
1824         char *name_munged, *other_munged;
1825         int complete_rewrite = 0;
1826         int len;
1827
1828         if (DIFF_PAIR_UNMERGED(p)) {
1829                 /* unmerged */
1830                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1831                 return;
1832         }
1833
1834         name = p->one->path;
1835         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1836         name_munged = quote_one(name);
1837         other_munged = quote_one(other);
1838         one = p->one; two = p->two;
1839
1840         diff_fill_sha1_info(one);
1841         diff_fill_sha1_info(two);
1842
1843         len = 0;
1844         switch (p->status) {
1845         case DIFF_STATUS_COPIED:
1846                 len += snprintf(msg + len, sizeof(msg) - len,
1847                                 "similarity index %d%%\n"
1848                                 "copy from %s\n"
1849                                 "copy to %s\n",
1850                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1851                                 name_munged, other_munged);
1852                 break;
1853         case DIFF_STATUS_RENAMED:
1854                 len += snprintf(msg + len, sizeof(msg) - len,
1855                                 "similarity index %d%%\n"
1856                                 "rename from %s\n"
1857                                 "rename to %s\n",
1858                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1859                                 name_munged, other_munged);
1860                 break;
1861         case DIFF_STATUS_MODIFIED:
1862                 if (p->score) {
1863                         len += snprintf(msg + len, sizeof(msg) - len,
1864                                         "dissimilarity index %d%%\n",
1865                                         (int)(0.5 + p->score *
1866                                               100.0/MAX_SCORE));
1867                         complete_rewrite = 1;
1868                         break;
1869                 }
1870                 /* fallthru */
1871         default:
1872                 /* nothing */
1873                 ;
1874         }
1875
1876         if (hashcmp(one->sha1, two->sha1)) {
1877                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1878
1879                 if (o->binary) {
1880                         mmfile_t mf;
1881                         if ((!fill_mmfile(&mf, one) && file_is_binary(one)) ||
1882                             (!fill_mmfile(&mf, two) && file_is_binary(two)))
1883                                 abbrev = 40;
1884                 }
1885                 len += snprintf(msg + len, sizeof(msg) - len,
1886                                 "index %.*s..%.*s",
1887                                 abbrev, sha1_to_hex(one->sha1),
1888                                 abbrev, sha1_to_hex(two->sha1));
1889                 if (one->mode == two->mode)
1890                         len += snprintf(msg + len, sizeof(msg) - len,
1891                                         " %06o", one->mode);
1892                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1893         }
1894
1895         if (len)
1896                 msg[--len] = 0;
1897         xfrm_msg = len ? msg : NULL;
1898
1899         if (!pgm &&
1900             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1901             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1902                 /* a filepair that changes between file and symlink
1903                  * needs to be split into deletion and creation.
1904                  */
1905                 struct diff_filespec *null = alloc_filespec(two->path);
1906                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1907                 free(null);
1908                 null = alloc_filespec(one->path);
1909                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1910                 free(null);
1911         }
1912         else
1913                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1914                              complete_rewrite);
1915
1916         free(name_munged);
1917         free(other_munged);
1918 }
1919
1920 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1921                          struct diffstat_t *diffstat)
1922 {
1923         const char *name;
1924         const char *other;
1925         int complete_rewrite = 0;
1926
1927         if (DIFF_PAIR_UNMERGED(p)) {
1928                 /* unmerged */
1929                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1930                 return;
1931         }
1932
1933         name = p->one->path;
1934         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1935
1936         diff_fill_sha1_info(p->one);
1937         diff_fill_sha1_info(p->two);
1938
1939         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1940                 complete_rewrite = 1;
1941         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1942 }
1943
1944 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1945 {
1946         const char *name;
1947         const char *other;
1948
1949         if (DIFF_PAIR_UNMERGED(p)) {
1950                 /* unmerged */
1951                 return;
1952         }
1953
1954         name = p->one->path;
1955         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1956
1957         diff_fill_sha1_info(p->one);
1958         diff_fill_sha1_info(p->two);
1959
1960         builtin_checkdiff(name, other, p->one, p->two, o);
1961 }
1962
1963 void diff_setup(struct diff_options *options)
1964 {
1965         memset(options, 0, sizeof(*options));
1966         options->line_termination = '\n';
1967         options->break_opt = -1;
1968         options->rename_limit = -1;
1969         options->context = 3;
1970         options->msg_sep = "";
1971
1972         options->change = diff_change;
1973         options->add_remove = diff_addremove;
1974         options->color_diff = diff_use_color_default;
1975         options->detect_rename = diff_detect_rename_default;
1976 }
1977
1978 int diff_setup_done(struct diff_options *options)
1979 {
1980         int count = 0;
1981
1982         if (options->output_format & DIFF_FORMAT_NAME)
1983                 count++;
1984         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
1985                 count++;
1986         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
1987                 count++;
1988         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
1989                 count++;
1990         if (count > 1)
1991                 die("--name-only, --name-status, --check and -s are mutually exclusive");
1992
1993         if (options->find_copies_harder)
1994                 options->detect_rename = DIFF_DETECT_COPY;
1995
1996         if (options->output_format & (DIFF_FORMAT_NAME |
1997                                       DIFF_FORMAT_NAME_STATUS |
1998                                       DIFF_FORMAT_CHECKDIFF |
1999                                       DIFF_FORMAT_NO_OUTPUT))
2000                 options->output_format &= ~(DIFF_FORMAT_RAW |
2001                                             DIFF_FORMAT_NUMSTAT |
2002                                             DIFF_FORMAT_DIFFSTAT |
2003                                             DIFF_FORMAT_SHORTSTAT |
2004                                             DIFF_FORMAT_SUMMARY |
2005                                             DIFF_FORMAT_PATCH);
2006
2007         /*
2008          * These cases always need recursive; we do not drop caller-supplied
2009          * recursive bits for other formats here.
2010          */
2011         if (options->output_format & (DIFF_FORMAT_PATCH |
2012                                       DIFF_FORMAT_NUMSTAT |
2013                                       DIFF_FORMAT_DIFFSTAT |
2014                                       DIFF_FORMAT_SHORTSTAT |
2015                                       DIFF_FORMAT_SUMMARY |
2016                                       DIFF_FORMAT_CHECKDIFF))
2017                 options->recursive = 1;
2018         /*
2019          * Also pickaxe would not work very well if you do not say recursive
2020          */
2021         if (options->pickaxe)
2022                 options->recursive = 1;
2023
2024         if (options->detect_rename && options->rename_limit < 0)
2025                 options->rename_limit = diff_rename_limit_default;
2026         if (options->setup & DIFF_SETUP_USE_CACHE) {
2027                 if (!active_cache)
2028                         /* read-cache does not die even when it fails
2029                          * so it is safe for us to do this here.  Also
2030                          * it does not smudge active_cache or active_nr
2031                          * when it fails, so we do not have to worry about
2032                          * cleaning it up ourselves either.
2033                          */
2034                         read_cache();
2035         }
2036         if (options->abbrev <= 0 || 40 < options->abbrev)
2037                 options->abbrev = 40; /* full */
2038
2039         /*
2040          * It does not make sense to show the first hit we happened
2041          * to have found.  It does not make sense not to return with
2042          * exit code in such a case either.
2043          */
2044         if (options->quiet) {
2045                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2046                 options->exit_with_status = 1;
2047         }
2048
2049         /*
2050          * If we postprocess in diffcore, we cannot simply return
2051          * upon the first hit.  We need to run diff as usual.
2052          */
2053         if (options->pickaxe || options->filter)
2054                 options->quiet = 0;
2055
2056         return 0;
2057 }
2058
2059 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2060 {
2061         char c, *eq;
2062         int len;
2063
2064         if (*arg != '-')
2065                 return 0;
2066         c = *++arg;
2067         if (!c)
2068                 return 0;
2069         if (c == arg_short) {
2070                 c = *++arg;
2071                 if (!c)
2072                         return 1;
2073                 if (val && isdigit(c)) {
2074                         char *end;
2075                         int n = strtoul(arg, &end, 10);
2076                         if (*end)
2077                                 return 0;
2078                         *val = n;
2079                         return 1;
2080                 }
2081                 return 0;
2082         }
2083         if (c != '-')
2084                 return 0;
2085         arg++;
2086         eq = strchr(arg, '=');
2087         if (eq)
2088                 len = eq - arg;
2089         else
2090                 len = strlen(arg);
2091         if (!len || strncmp(arg, arg_long, len))
2092                 return 0;
2093         if (eq) {
2094                 int n;
2095                 char *end;
2096                 if (!isdigit(*++eq))
2097                         return 0;
2098                 n = strtoul(eq, &end, 10);
2099                 if (*end)
2100                         return 0;
2101                 *val = n;
2102         }
2103         return 1;
2104 }
2105
2106 static int diff_scoreopt_parse(const char *opt);
2107
2108 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2109 {
2110         const char *arg = av[0];
2111         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2112                 options->output_format |= DIFF_FORMAT_PATCH;
2113         else if (opt_arg(arg, 'U', "unified", &options->context))
2114                 options->output_format |= DIFF_FORMAT_PATCH;
2115         else if (!strcmp(arg, "--raw"))
2116                 options->output_format |= DIFF_FORMAT_RAW;
2117         else if (!strcmp(arg, "--patch-with-raw")) {
2118                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2119         }
2120         else if (!strcmp(arg, "--numstat")) {
2121                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2122         }
2123         else if (!strcmp(arg, "--shortstat")) {
2124                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2125         }
2126         else if (!prefixcmp(arg, "--stat")) {
2127                 char *end;
2128                 int width = options->stat_width;
2129                 int name_width = options->stat_name_width;
2130                 arg += 6;
2131                 end = (char *)arg;
2132
2133                 switch (*arg) {
2134                 case '-':
2135                         if (!prefixcmp(arg, "-width="))
2136                                 width = strtoul(arg + 7, &end, 10);
2137                         else if (!prefixcmp(arg, "-name-width="))
2138                                 name_width = strtoul(arg + 12, &end, 10);
2139                         break;
2140                 case '=':
2141                         width = strtoul(arg+1, &end, 10);
2142                         if (*end == ',')
2143                                 name_width = strtoul(end+1, &end, 10);
2144                 }
2145
2146                 /* Important! This checks all the error cases! */
2147                 if (*end)
2148                         return 0;
2149                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2150                 options->stat_name_width = name_width;
2151                 options->stat_width = width;
2152         }
2153         else if (!strcmp(arg, "--check"))
2154                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2155         else if (!strcmp(arg, "--summary"))
2156                 options->output_format |= DIFF_FORMAT_SUMMARY;
2157         else if (!strcmp(arg, "--patch-with-stat")) {
2158                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2159         }
2160         else if (!strcmp(arg, "-z"))
2161                 options->line_termination = 0;
2162         else if (!prefixcmp(arg, "-l"))
2163                 options->rename_limit = strtoul(arg+2, NULL, 10);
2164         else if (!strcmp(arg, "--full-index"))
2165                 options->full_index = 1;
2166         else if (!strcmp(arg, "--binary")) {
2167                 options->output_format |= DIFF_FORMAT_PATCH;
2168                 options->binary = 1;
2169         }
2170         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
2171                 options->text = 1;
2172         }
2173         else if (!strcmp(arg, "--name-only"))
2174                 options->output_format |= DIFF_FORMAT_NAME;
2175         else if (!strcmp(arg, "--name-status"))
2176                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2177         else if (!strcmp(arg, "-R"))
2178                 options->reverse_diff = 1;
2179         else if (!prefixcmp(arg, "-S"))
2180                 options->pickaxe = arg + 2;
2181         else if (!strcmp(arg, "-s")) {
2182                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2183         }
2184         else if (!prefixcmp(arg, "-O"))
2185                 options->orderfile = arg + 2;
2186         else if (!prefixcmp(arg, "--diff-filter="))
2187                 options->filter = arg + 14;
2188         else if (!strcmp(arg, "--pickaxe-all"))
2189                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2190         else if (!strcmp(arg, "--pickaxe-regex"))
2191                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2192         else if (!prefixcmp(arg, "-B")) {
2193                 if ((options->break_opt =
2194                      diff_scoreopt_parse(arg)) == -1)
2195                         return -1;
2196         }
2197         else if (!prefixcmp(arg, "-M")) {
2198                 if ((options->rename_score =
2199                      diff_scoreopt_parse(arg)) == -1)
2200                         return -1;
2201                 options->detect_rename = DIFF_DETECT_RENAME;
2202         }
2203         else if (!prefixcmp(arg, "-C")) {
2204                 if (options->detect_rename == DIFF_DETECT_COPY)
2205                         options->find_copies_harder = 1;
2206                 if ((options->rename_score =
2207                      diff_scoreopt_parse(arg)) == -1)
2208                         return -1;
2209                 options->detect_rename = DIFF_DETECT_COPY;
2210         }
2211         else if (!strcmp(arg, "--find-copies-harder"))
2212                 options->find_copies_harder = 1;
2213         else if (!strcmp(arg, "--abbrev"))
2214                 options->abbrev = DEFAULT_ABBREV;
2215         else if (!prefixcmp(arg, "--abbrev=")) {
2216                 options->abbrev = strtoul(arg + 9, NULL, 10);
2217                 if (options->abbrev < MINIMUM_ABBREV)
2218                         options->abbrev = MINIMUM_ABBREV;
2219                 else if (40 < options->abbrev)
2220                         options->abbrev = 40;
2221         }
2222         else if (!strcmp(arg, "--color"))
2223                 options->color_diff = 1;
2224         else if (!strcmp(arg, "--no-color"))
2225                 options->color_diff = 0;
2226         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2227                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2228         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2229                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2230         else if (!strcmp(arg, "--ignore-space-at-eol"))
2231                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2232         else if (!strcmp(arg, "--color-words"))
2233                 options->color_diff = options->color_diff_words = 1;
2234         else if (!strcmp(arg, "--no-renames"))
2235                 options->detect_rename = 0;
2236         else if (!strcmp(arg, "--exit-code"))
2237                 options->exit_with_status = 1;
2238         else if (!strcmp(arg, "--quiet"))
2239                 options->quiet = 1;
2240         else
2241                 return 0;
2242         return 1;
2243 }
2244
2245 static int parse_num(const char **cp_p)
2246 {
2247         unsigned long num, scale;
2248         int ch, dot;
2249         const char *cp = *cp_p;
2250
2251         num = 0;
2252         scale = 1;
2253         dot = 0;
2254         for(;;) {
2255                 ch = *cp;
2256                 if ( !dot && ch == '.' ) {
2257                         scale = 1;
2258                         dot = 1;
2259                 } else if ( ch == '%' ) {
2260                         scale = dot ? scale*100 : 100;
2261                         cp++;   /* % is always at the end */
2262                         break;
2263                 } else if ( ch >= '0' && ch <= '9' ) {
2264                         if ( scale < 100000 ) {
2265                                 scale *= 10;
2266                                 num = (num*10) + (ch-'0');
2267                         }
2268                 } else {
2269                         break;
2270                 }
2271                 cp++;
2272         }
2273         *cp_p = cp;
2274
2275         /* user says num divided by scale and we say internally that
2276          * is MAX_SCORE * num / scale.
2277          */
2278         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2279 }
2280
2281 static int diff_scoreopt_parse(const char *opt)
2282 {
2283         int opt1, opt2, cmd;
2284
2285         if (*opt++ != '-')
2286                 return -1;
2287         cmd = *opt++;
2288         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2289                 return -1; /* that is not a -M, -C nor -B option */
2290
2291         opt1 = parse_num(&opt);
2292         if (cmd != 'B')
2293                 opt2 = 0;
2294         else {
2295                 if (*opt == 0)
2296                         opt2 = 0;
2297                 else if (*opt != '/')
2298                         return -1; /* we expect -B80/99 or -B80 */
2299                 else {
2300                         opt++;
2301                         opt2 = parse_num(&opt);
2302                 }
2303         }
2304         if (*opt != 0)
2305                 return -1;
2306         return opt1 | (opt2 << 16);
2307 }
2308
2309 struct diff_queue_struct diff_queued_diff;
2310
2311 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2312 {
2313         if (queue->alloc <= queue->nr) {
2314                 queue->alloc = alloc_nr(queue->alloc);
2315                 queue->queue = xrealloc(queue->queue,
2316                                         sizeof(dp) * queue->alloc);
2317         }
2318         queue->queue[queue->nr++] = dp;
2319 }
2320
2321 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2322                                  struct diff_filespec *one,
2323                                  struct diff_filespec *two)
2324 {
2325         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2326         dp->one = one;
2327         dp->two = two;
2328         if (queue)
2329                 diff_q(queue, dp);
2330         return dp;
2331 }
2332
2333 void diff_free_filepair(struct diff_filepair *p)
2334 {
2335         diff_free_filespec_data(p->one);
2336         diff_free_filespec_data(p->two);
2337         free(p->one);
2338         free(p->two);
2339         free(p);
2340 }
2341
2342 /* This is different from find_unique_abbrev() in that
2343  * it stuffs the result with dots for alignment.
2344  */
2345 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2346 {
2347         int abblen;
2348         const char *abbrev;
2349         if (len == 40)
2350                 return sha1_to_hex(sha1);
2351
2352         abbrev = find_unique_abbrev(sha1, len);
2353         if (!abbrev)
2354                 return sha1_to_hex(sha1);
2355         abblen = strlen(abbrev);
2356         if (abblen < 37) {
2357                 static char hex[41];
2358                 if (len < abblen && abblen <= len + 2)
2359                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2360                 else
2361                         sprintf(hex, "%s...", abbrev);
2362                 return hex;
2363         }
2364         return sha1_to_hex(sha1);
2365 }
2366
2367 static void diff_flush_raw(struct diff_filepair *p,
2368                            struct diff_options *options)
2369 {
2370         int two_paths;
2371         char status[10];
2372         int abbrev = options->abbrev;
2373         const char *path_one, *path_two;
2374         int inter_name_termination = '\t';
2375         int line_termination = options->line_termination;
2376
2377         if (!line_termination)
2378                 inter_name_termination = 0;
2379
2380         path_one = p->one->path;
2381         path_two = p->two->path;
2382         if (line_termination) {
2383                 path_one = quote_one(path_one);
2384                 path_two = quote_one(path_two);
2385         }
2386
2387         if (p->score)
2388                 sprintf(status, "%c%03d", p->status,
2389                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
2390         else {
2391                 status[0] = p->status;
2392                 status[1] = 0;
2393         }
2394         switch (p->status) {
2395         case DIFF_STATUS_COPIED:
2396         case DIFF_STATUS_RENAMED:
2397                 two_paths = 1;
2398                 break;
2399         case DIFF_STATUS_ADDED:
2400         case DIFF_STATUS_DELETED:
2401                 two_paths = 0;
2402                 break;
2403         default:
2404                 two_paths = 0;
2405                 break;
2406         }
2407         if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
2408                 printf(":%06o %06o %s ",
2409                        p->one->mode, p->two->mode,
2410                        diff_unique_abbrev(p->one->sha1, abbrev));
2411                 printf("%s ",
2412                        diff_unique_abbrev(p->two->sha1, abbrev));
2413         }
2414         printf("%s%c%s", status, inter_name_termination, path_one);
2415         if (two_paths)
2416                 printf("%c%s", inter_name_termination, path_two);
2417         putchar(line_termination);
2418         if (path_one != p->one->path)
2419                 free((void*)path_one);
2420         if (path_two != p->two->path)
2421                 free((void*)path_two);
2422 }
2423
2424 static void diff_flush_name(struct diff_filepair *p, struct diff_options *opt)
2425 {
2426         char *path = p->two->path;
2427
2428         if (opt->line_termination)
2429                 path = quote_one(p->two->path);
2430         printf("%s%c", path, opt->line_termination);
2431         if (p->two->path != path)
2432                 free(path);
2433 }
2434
2435 int diff_unmodified_pair(struct diff_filepair *p)
2436 {
2437         /* This function is written stricter than necessary to support
2438          * the currently implemented transformers, but the idea is to
2439          * let transformers to produce diff_filepairs any way they want,
2440          * and filter and clean them up here before producing the output.
2441          */
2442         struct diff_filespec *one, *two;
2443
2444         if (DIFF_PAIR_UNMERGED(p))
2445                 return 0; /* unmerged is interesting */
2446
2447         one = p->one;
2448         two = p->two;
2449
2450         /* deletion, addition, mode or type change
2451          * and rename are all interesting.
2452          */
2453         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2454             DIFF_PAIR_MODE_CHANGED(p) ||
2455             strcmp(one->path, two->path))
2456                 return 0;
2457
2458         /* both are valid and point at the same path.  that is, we are
2459          * dealing with a change.
2460          */
2461         if (one->sha1_valid && two->sha1_valid &&
2462             !hashcmp(one->sha1, two->sha1))
2463                 return 1; /* no change */
2464         if (!one->sha1_valid && !two->sha1_valid)
2465                 return 1; /* both look at the same file on the filesystem. */
2466         return 0;
2467 }
2468
2469 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2470 {
2471         if (diff_unmodified_pair(p))
2472                 return;
2473
2474         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2475             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2476                 return; /* no tree diffs in patch format */
2477
2478         run_diff(p, o);
2479 }
2480
2481 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2482                             struct diffstat_t *diffstat)
2483 {
2484         if (diff_unmodified_pair(p))
2485                 return;
2486
2487         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2488             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2489                 return; /* no tree diffs in patch format */
2490
2491         run_diffstat(p, o, diffstat);
2492 }
2493
2494 static void diff_flush_checkdiff(struct diff_filepair *p,
2495                 struct diff_options *o)
2496 {
2497         if (diff_unmodified_pair(p))
2498                 return;
2499
2500         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2501             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2502                 return; /* no tree diffs in patch format */
2503
2504         run_checkdiff(p, o);
2505 }
2506
2507 int diff_queue_is_empty(void)
2508 {
2509         struct diff_queue_struct *q = &diff_queued_diff;
2510         int i;
2511         for (i = 0; i < q->nr; i++)
2512                 if (!diff_unmodified_pair(q->queue[i]))
2513                         return 0;
2514         return 1;
2515 }
2516
2517 #if DIFF_DEBUG
2518 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2519 {
2520         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2521                 x, one ? one : "",
2522                 s->path,
2523                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2524                 s->mode,
2525                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2526         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2527                 x, one ? one : "",
2528                 s->size, s->xfrm_flags);
2529 }
2530
2531 void diff_debug_filepair(const struct diff_filepair *p, int i)
2532 {
2533         diff_debug_filespec(p->one, i, "one");
2534         diff_debug_filespec(p->two, i, "two");
2535         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2536                 p->score, p->status ? p->status : '?',
2537                 p->source_stays, p->broken_pair);
2538 }
2539
2540 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2541 {
2542         int i;
2543         if (msg)
2544                 fprintf(stderr, "%s\n", msg);
2545         fprintf(stderr, "q->nr = %d\n", q->nr);
2546         for (i = 0; i < q->nr; i++) {
2547                 struct diff_filepair *p = q->queue[i];
2548                 diff_debug_filepair(p, i);
2549         }
2550 }
2551 #endif
2552
2553 static void diff_resolve_rename_copy(void)
2554 {
2555         int i, j;
2556         struct diff_filepair *p, *pp;
2557         struct diff_queue_struct *q = &diff_queued_diff;
2558
2559         diff_debug_queue("resolve-rename-copy", q);
2560
2561         for (i = 0; i < q->nr; i++) {
2562                 p = q->queue[i];
2563                 p->status = 0; /* undecided */
2564                 if (DIFF_PAIR_UNMERGED(p))
2565                         p->status = DIFF_STATUS_UNMERGED;
2566                 else if (!DIFF_FILE_VALID(p->one))
2567                         p->status = DIFF_STATUS_ADDED;
2568                 else if (!DIFF_FILE_VALID(p->two))
2569                         p->status = DIFF_STATUS_DELETED;
2570                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2571                         p->status = DIFF_STATUS_TYPE_CHANGED;
2572
2573                 /* from this point on, we are dealing with a pair
2574                  * whose both sides are valid and of the same type, i.e.
2575                  * either in-place edit or rename/copy edit.
2576                  */
2577                 else if (DIFF_PAIR_RENAME(p)) {
2578                         if (p->source_stays) {
2579                                 p->status = DIFF_STATUS_COPIED;
2580                                 continue;
2581                         }
2582                         /* See if there is some other filepair that
2583                          * copies from the same source as us.  If so
2584                          * we are a copy.  Otherwise we are either a
2585                          * copy if the path stays, or a rename if it
2586                          * does not, but we already handled "stays" case.
2587                          */
2588                         for (j = i + 1; j < q->nr; j++) {
2589                                 pp = q->queue[j];
2590                                 if (strcmp(pp->one->path, p->one->path))
2591                                         continue; /* not us */
2592                                 if (!DIFF_PAIR_RENAME(pp))
2593                                         continue; /* not a rename/copy */
2594                                 /* pp is a rename/copy from the same source */
2595                                 p->status = DIFF_STATUS_COPIED;
2596                                 break;
2597                         }
2598                         if (!p->status)
2599                                 p->status = DIFF_STATUS_RENAMED;
2600                 }
2601                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2602                          p->one->mode != p->two->mode ||
2603                          is_null_sha1(p->one->sha1))
2604                         p->status = DIFF_STATUS_MODIFIED;
2605                 else {
2606                         /* This is a "no-change" entry and should not
2607                          * happen anymore, but prepare for broken callers.
2608                          */
2609                         error("feeding unmodified %s to diffcore",
2610                               p->one->path);
2611                         p->status = DIFF_STATUS_UNKNOWN;
2612                 }
2613         }
2614         diff_debug_queue("resolve-rename-copy done", q);
2615 }
2616
2617 static int check_pair_status(struct diff_filepair *p)
2618 {
2619         switch (p->status) {
2620         case DIFF_STATUS_UNKNOWN:
2621                 return 0;
2622         case 0:
2623                 die("internal error in diff-resolve-rename-copy");
2624         default:
2625                 return 1;
2626         }
2627 }
2628
2629 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2630 {
2631         int fmt = opt->output_format;
2632
2633         if (fmt & DIFF_FORMAT_CHECKDIFF)
2634                 diff_flush_checkdiff(p, opt);
2635         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2636                 diff_flush_raw(p, opt);
2637         else if (fmt & DIFF_FORMAT_NAME)
2638                 diff_flush_name(p, opt);
2639 }
2640
2641 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2642 {
2643         char *name = quote_one(fs->path);
2644         if (fs->mode)
2645                 printf(" %s mode %06o %s\n", newdelete, fs->mode, name);
2646         else
2647                 printf(" %s %s\n", newdelete, name);
2648         free(name);
2649 }
2650
2651
2652 static void show_mode_change(struct diff_filepair *p, int show_name)
2653 {
2654         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2655                 if (show_name) {
2656                         char *name = quote_one(p->two->path);
2657                         printf(" mode change %06o => %06o %s\n",
2658                                p->one->mode, p->two->mode, name);
2659                         free(name);
2660                 }
2661                 else
2662                         printf(" mode change %06o => %06o\n",
2663                                p->one->mode, p->two->mode);
2664         }
2665 }
2666
2667 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2668 {
2669         char *names = pprint_rename(p->one->path, p->two->path);
2670
2671         printf(" %s %s (%d%%)\n", renamecopy, names,
2672                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2673         free(names);
2674         show_mode_change(p, 0);
2675 }
2676
2677 static void diff_summary(struct diff_filepair *p)
2678 {
2679         switch(p->status) {
2680         case DIFF_STATUS_DELETED:
2681                 show_file_mode_name("delete", p->one);
2682                 break;
2683         case DIFF_STATUS_ADDED:
2684                 show_file_mode_name("create", p->two);
2685                 break;
2686         case DIFF_STATUS_COPIED:
2687                 show_rename_copy("copy", p);
2688                 break;
2689         case DIFF_STATUS_RENAMED:
2690                 show_rename_copy("rename", p);
2691                 break;
2692         default:
2693                 if (p->score) {
2694                         char *name = quote_one(p->two->path);
2695                         printf(" rewrite %s (%d%%)\n", name,
2696                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2697                         free(name);
2698                         show_mode_change(p, 0);
2699                 } else  show_mode_change(p, 1);
2700                 break;
2701         }
2702 }
2703
2704 struct patch_id_t {
2705         struct xdiff_emit_state xm;
2706         SHA_CTX *ctx;
2707         int patchlen;
2708 };
2709
2710 static int remove_space(char *line, int len)
2711 {
2712         int i;
2713         char *dst = line;
2714         unsigned char c;
2715
2716         for (i = 0; i < len; i++)
2717                 if (!isspace((c = line[i])))
2718                         *dst++ = c;
2719
2720         return dst - line;
2721 }
2722
2723 static void patch_id_consume(void *priv, char *line, unsigned long len)
2724 {
2725         struct patch_id_t *data = priv;
2726         int new_len;
2727
2728         /* Ignore line numbers when computing the SHA1 of the patch */
2729         if (!prefixcmp(line, "@@ -"))
2730                 return;
2731
2732         new_len = remove_space(line, len);
2733
2734         SHA1_Update(data->ctx, line, new_len);
2735         data->patchlen += new_len;
2736 }
2737
2738 /* returns 0 upon success, and writes result into sha1 */
2739 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2740 {
2741         struct diff_queue_struct *q = &diff_queued_diff;
2742         int i;
2743         SHA_CTX ctx;
2744         struct patch_id_t data;
2745         char buffer[PATH_MAX * 4 + 20];
2746
2747         SHA1_Init(&ctx);
2748         memset(&data, 0, sizeof(struct patch_id_t));
2749         data.ctx = &ctx;
2750         data.xm.consume = patch_id_consume;
2751
2752         for (i = 0; i < q->nr; i++) {
2753                 xpparam_t xpp;
2754                 xdemitconf_t xecfg;
2755                 xdemitcb_t ecb;
2756                 mmfile_t mf1, mf2;
2757                 struct diff_filepair *p = q->queue[i];
2758                 int len1, len2;
2759
2760                 if (p->status == 0)
2761                         return error("internal diff status error");
2762                 if (p->status == DIFF_STATUS_UNKNOWN)
2763                         continue;
2764                 if (diff_unmodified_pair(p))
2765                         continue;
2766                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2767                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2768                         continue;
2769                 if (DIFF_PAIR_UNMERGED(p))
2770                         continue;
2771
2772                 diff_fill_sha1_info(p->one);
2773                 diff_fill_sha1_info(p->two);
2774                 if (fill_mmfile(&mf1, p->one) < 0 ||
2775                                 fill_mmfile(&mf2, p->two) < 0)
2776                         return error("unable to read files to diff");
2777
2778                 /* Maybe hash p->two? into the patch id? */
2779                 if (file_is_binary(p->two))
2780                         continue;
2781
2782                 len1 = remove_space(p->one->path, strlen(p->one->path));
2783                 len2 = remove_space(p->two->path, strlen(p->two->path));
2784                 if (p->one->mode == 0)
2785                         len1 = snprintf(buffer, sizeof(buffer),
2786                                         "diff--gita/%.*sb/%.*s"
2787                                         "newfilemode%06o"
2788                                         "---/dev/null"
2789                                         "+++b/%.*s",
2790                                         len1, p->one->path,
2791                                         len2, p->two->path,
2792                                         p->two->mode,
2793                                         len2, p->two->path);
2794                 else if (p->two->mode == 0)
2795                         len1 = snprintf(buffer, sizeof(buffer),
2796                                         "diff--gita/%.*sb/%.*s"
2797                                         "deletedfilemode%06o"
2798                                         "---a/%.*s"
2799                                         "+++/dev/null",
2800                                         len1, p->one->path,
2801                                         len2, p->two->path,
2802                                         p->one->mode,
2803                                         len1, p->one->path);
2804                 else
2805                         len1 = snprintf(buffer, sizeof(buffer),
2806                                         "diff--gita/%.*sb/%.*s"
2807                                         "---a/%.*s"
2808                                         "+++b/%.*s",
2809                                         len1, p->one->path,
2810                                         len2, p->two->path,
2811                                         len1, p->one->path,
2812                                         len2, p->two->path);
2813                 SHA1_Update(&ctx, buffer, len1);
2814
2815                 xpp.flags = XDF_NEED_MINIMAL;
2816                 xecfg.ctxlen = 3;
2817                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2818                 ecb.outf = xdiff_outf;
2819                 ecb.priv = &data;
2820                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2821         }
2822
2823         SHA1_Final(sha1, &ctx);
2824         return 0;
2825 }
2826
2827 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2828 {
2829         struct diff_queue_struct *q = &diff_queued_diff;
2830         int i;
2831         int result = diff_get_patch_id(options, sha1);
2832
2833         for (i = 0; i < q->nr; i++)
2834                 diff_free_filepair(q->queue[i]);
2835
2836         free(q->queue);
2837         q->queue = NULL;
2838         q->nr = q->alloc = 0;
2839
2840         return result;
2841 }
2842
2843 static int is_summary_empty(const struct diff_queue_struct *q)
2844 {
2845         int i;
2846
2847         for (i = 0; i < q->nr; i++) {
2848                 const struct diff_filepair *p = q->queue[i];
2849
2850                 switch (p->status) {
2851                 case DIFF_STATUS_DELETED:
2852                 case DIFF_STATUS_ADDED:
2853                 case DIFF_STATUS_COPIED:
2854                 case DIFF_STATUS_RENAMED:
2855                         return 0;
2856                 default:
2857                         if (p->score)
2858                                 return 0;
2859                         if (p->one->mode && p->two->mode &&
2860                             p->one->mode != p->two->mode)
2861                                 return 0;
2862                         break;
2863                 }
2864         }
2865         return 1;
2866 }
2867
2868 void diff_flush(struct diff_options *options)
2869 {
2870         struct diff_queue_struct *q = &diff_queued_diff;
2871         int i, output_format = options->output_format;
2872         int separator = 0;
2873
2874         /*
2875          * Order: raw, stat, summary, patch
2876          * or:    name/name-status/checkdiff (other bits clear)
2877          */
2878         if (!q->nr)
2879                 goto free_queue;
2880
2881         if (output_format & (DIFF_FORMAT_RAW |
2882                              DIFF_FORMAT_NAME |
2883                              DIFF_FORMAT_NAME_STATUS |
2884                              DIFF_FORMAT_CHECKDIFF)) {
2885                 for (i = 0; i < q->nr; i++) {
2886                         struct diff_filepair *p = q->queue[i];
2887                         if (check_pair_status(p))
2888                                 flush_one_pair(p, options);
2889                 }
2890                 separator++;
2891         }
2892
2893         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2894                 struct diffstat_t diffstat;
2895
2896                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2897                 diffstat.xm.consume = diffstat_consume;
2898                 for (i = 0; i < q->nr; i++) {
2899                         struct diff_filepair *p = q->queue[i];
2900                         if (check_pair_status(p))
2901                                 diff_flush_stat(p, options, &diffstat);
2902                 }
2903                 if (output_format & DIFF_FORMAT_NUMSTAT)
2904                         show_numstat(&diffstat, options);
2905                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2906                         show_stats(&diffstat, options);
2907                 else if (output_format & DIFF_FORMAT_SHORTSTAT)
2908                         show_shortstats(&diffstat);
2909                 separator++;
2910         }
2911
2912         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2913                 for (i = 0; i < q->nr; i++)
2914                         diff_summary(q->queue[i]);
2915                 separator++;
2916         }
2917
2918         if (output_format & DIFF_FORMAT_PATCH) {
2919                 if (separator) {
2920                         if (options->stat_sep) {
2921                                 /* attach patch instead of inline */
2922                                 fputs(options->stat_sep, stdout);
2923                         } else {
2924                                 putchar(options->line_termination);
2925                         }
2926                 }
2927
2928                 for (i = 0; i < q->nr; i++) {
2929                         struct diff_filepair *p = q->queue[i];
2930                         if (check_pair_status(p))
2931                                 diff_flush_patch(p, options);
2932                 }
2933         }
2934
2935         if (output_format & DIFF_FORMAT_CALLBACK)
2936                 options->format_callback(q, options, options->format_callback_data);
2937
2938         for (i = 0; i < q->nr; i++)
2939                 diff_free_filepair(q->queue[i]);
2940 free_queue:
2941         free(q->queue);
2942         q->queue = NULL;
2943         q->nr = q->alloc = 0;
2944 }
2945
2946 static void diffcore_apply_filter(const char *filter)
2947 {
2948         int i;
2949         struct diff_queue_struct *q = &diff_queued_diff;
2950         struct diff_queue_struct outq;
2951         outq.queue = NULL;
2952         outq.nr = outq.alloc = 0;
2953
2954         if (!filter)
2955                 return;
2956
2957         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2958                 int found;
2959                 for (i = found = 0; !found && i < q->nr; i++) {
2960                         struct diff_filepair *p = q->queue[i];
2961                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2962                              ((p->score &&
2963                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2964                               (!p->score &&
2965                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2966                             ((p->status != DIFF_STATUS_MODIFIED) &&
2967                              strchr(filter, p->status)))
2968                                 found++;
2969                 }
2970                 if (found)
2971                         return;
2972
2973                 /* otherwise we will clear the whole queue
2974                  * by copying the empty outq at the end of this
2975                  * function, but first clear the current entries
2976                  * in the queue.
2977                  */
2978                 for (i = 0; i < q->nr; i++)
2979                         diff_free_filepair(q->queue[i]);
2980         }
2981         else {
2982                 /* Only the matching ones */
2983                 for (i = 0; i < q->nr; i++) {
2984                         struct diff_filepair *p = q->queue[i];
2985
2986                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2987                              ((p->score &&
2988                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2989                               (!p->score &&
2990                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2991                             ((p->status != DIFF_STATUS_MODIFIED) &&
2992                              strchr(filter, p->status)))
2993                                 diff_q(&outq, p);
2994                         else
2995                                 diff_free_filepair(p);
2996                 }
2997         }
2998         free(q->queue);
2999         *q = outq;
3000 }
3001
3002 void diffcore_std(struct diff_options *options)
3003 {
3004         if (options->quiet)
3005                 return;
3006         if (options->break_opt != -1)
3007                 diffcore_break(options->break_opt);
3008         if (options->detect_rename)
3009                 diffcore_rename(options);
3010         if (options->break_opt != -1)
3011                 diffcore_merge_broken();
3012         if (options->pickaxe)
3013                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3014         if (options->orderfile)
3015                 diffcore_order(options->orderfile);
3016         diff_resolve_rename_copy();
3017         diffcore_apply_filter(options->filter);
3018
3019         options->has_changes = !!diff_queued_diff.nr;
3020 }
3021
3022
3023 void diff_addremove(struct diff_options *options,
3024                     int addremove, unsigned mode,
3025                     const unsigned char *sha1,
3026                     const char *base, const char *path)
3027 {
3028         char concatpath[PATH_MAX];
3029         struct diff_filespec *one, *two;
3030
3031         /* This may look odd, but it is a preparation for
3032          * feeding "there are unchanged files which should
3033          * not produce diffs, but when you are doing copy
3034          * detection you would need them, so here they are"
3035          * entries to the diff-core.  They will be prefixed
3036          * with something like '=' or '*' (I haven't decided
3037          * which but should not make any difference).
3038          * Feeding the same new and old to diff_change()
3039          * also has the same effect.
3040          * Before the final output happens, they are pruned after
3041          * merged into rename/copy pairs as appropriate.
3042          */
3043         if (options->reverse_diff)
3044                 addremove = (addremove == '+' ? '-' :
3045                              addremove == '-' ? '+' : addremove);
3046
3047         if (!path) path = "";
3048         sprintf(concatpath, "%s%s", base, path);
3049         one = alloc_filespec(concatpath);
3050         two = alloc_filespec(concatpath);
3051
3052         if (addremove != '+')
3053                 fill_filespec(one, sha1, mode);
3054         if (addremove != '-')
3055                 fill_filespec(two, sha1, mode);
3056
3057         diff_queue(&diff_queued_diff, one, two);
3058         options->has_changes = 1;
3059 }
3060
3061 void diff_change(struct diff_options *options,
3062                  unsigned old_mode, unsigned new_mode,
3063                  const unsigned char *old_sha1,
3064                  const unsigned char *new_sha1,
3065                  const char *base, const char *path)
3066 {
3067         char concatpath[PATH_MAX];
3068         struct diff_filespec *one, *two;
3069
3070         if (options->reverse_diff) {
3071                 unsigned tmp;
3072                 const unsigned char *tmp_c;
3073                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3074                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3075         }
3076         if (!path) path = "";
3077         sprintf(concatpath, "%s%s", base, path);
3078         one = alloc_filespec(concatpath);
3079         two = alloc_filespec(concatpath);
3080         fill_filespec(one, old_sha1, old_mode);
3081         fill_filespec(two, new_sha1, new_mode);
3082
3083         diff_queue(&diff_queued_diff, one, two);
3084         options->has_changes = 1;
3085 }
3086
3087 void diff_unmerge(struct diff_options *options,
3088                   const char *path,
3089                   unsigned mode, const unsigned char *sha1)
3090 {
3091         struct diff_filespec *one, *two;
3092         one = alloc_filespec(path);
3093         two = alloc_filespec(path);
3094         fill_filespec(one, sha1, mode);
3095         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3096 }