Expose subprojects as special files to "git diff" machinery
[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
12 #ifdef NO_FAST_WORKING_DIRECTORY
13 #define FAST_WORKING_DIRECTORY 0
14 #else
15 #define FAST_WORKING_DIRECTORY 1
16 #endif
17
18 static int use_size_cache;
19
20 static int diff_detect_rename_default;
21 static int diff_rename_limit_default = -1;
22 static int diff_use_color_default;
23
24 static char diff_colors[][COLOR_MAXLEN] = {
25         "\033[m",       /* reset */
26         "",             /* PLAIN (normal) */
27         "\033[1m",      /* METAINFO (bold) */
28         "\033[36m",     /* FRAGINFO (cyan) */
29         "\033[31m",     /* OLD (red) */
30         "\033[32m",     /* NEW (green) */
31         "\033[33m",     /* COMMIT (yellow) */
32         "\033[41m",     /* WHITESPACE (red background) */
33 };
34
35 static int parse_diff_color_slot(const char *var, int ofs)
36 {
37         if (!strcasecmp(var+ofs, "plain"))
38                 return DIFF_PLAIN;
39         if (!strcasecmp(var+ofs, "meta"))
40                 return DIFF_METAINFO;
41         if (!strcasecmp(var+ofs, "frag"))
42                 return DIFF_FRAGINFO;
43         if (!strcasecmp(var+ofs, "old"))
44                 return DIFF_FILE_OLD;
45         if (!strcasecmp(var+ofs, "new"))
46                 return DIFF_FILE_NEW;
47         if (!strcasecmp(var+ofs, "commit"))
48                 return DIFF_COMMIT;
49         if (!strcasecmp(var+ofs, "whitespace"))
50                 return DIFF_WHITESPACE;
51         die("bad config variable '%s'", var);
52 }
53
54 /*
55  * These are to give UI layer defaults.
56  * The core-level commands such as git-diff-files should
57  * never be affected by the setting of diff.renames
58  * the user happens to have in the configuration file.
59  */
60 int git_diff_ui_config(const char *var, const char *value)
61 {
62         if (!strcmp(var, "diff.renamelimit")) {
63                 diff_rename_limit_default = git_config_int(var, value);
64                 return 0;
65         }
66         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
67                 diff_use_color_default = git_config_colorbool(var, value);
68                 return 0;
69         }
70         if (!strcmp(var, "diff.renames")) {
71                 if (!value)
72                         diff_detect_rename_default = DIFF_DETECT_RENAME;
73                 else if (!strcasecmp(value, "copies") ||
74                          !strcasecmp(value, "copy"))
75                         diff_detect_rename_default = DIFF_DETECT_COPY;
76                 else if (git_config_bool(var,value))
77                         diff_detect_rename_default = DIFF_DETECT_RENAME;
78                 return 0;
79         }
80         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
81                 int slot = parse_diff_color_slot(var, 11);
82                 color_parse(value, var, diff_colors[slot]);
83                 return 0;
84         }
85         return git_default_config(var, value);
86 }
87
88 static char *quote_one(const char *str)
89 {
90         int needlen;
91         char *xp;
92
93         if (!str)
94                 return NULL;
95         needlen = quote_c_style(str, NULL, NULL, 0);
96         if (!needlen)
97                 return xstrdup(str);
98         xp = xmalloc(needlen + 1);
99         quote_c_style(str, xp, NULL, 0);
100         return xp;
101 }
102
103 static char *quote_two(const char *one, const char *two)
104 {
105         int need_one = quote_c_style(one, NULL, NULL, 1);
106         int need_two = quote_c_style(two, NULL, NULL, 1);
107         char *xp;
108
109         if (need_one + need_two) {
110                 if (!need_one) need_one = strlen(one);
111                 if (!need_two) need_one = strlen(two);
112
113                 xp = xmalloc(need_one + need_two + 3);
114                 xp[0] = '"';
115                 quote_c_style(one, xp + 1, NULL, 1);
116                 quote_c_style(two, xp + need_one + 1, NULL, 1);
117                 strcpy(xp + need_one + need_two + 1, "\"");
118                 return xp;
119         }
120         need_one = strlen(one);
121         need_two = strlen(two);
122         xp = xmalloc(need_one + need_two + 1);
123         strcpy(xp, one);
124         strcpy(xp + need_one, two);
125         return xp;
126 }
127
128 static const char *external_diff(void)
129 {
130         static const char *external_diff_cmd = NULL;
131         static int done_preparing = 0;
132
133         if (done_preparing)
134                 return external_diff_cmd;
135         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
136         done_preparing = 1;
137         return external_diff_cmd;
138 }
139
140 #define TEMPFILE_PATH_LEN               50
141
142 static struct diff_tempfile {
143         const char *name; /* filename external diff should read from */
144         char hex[41];
145         char mode[10];
146         char tmp_path[TEMPFILE_PATH_LEN];
147 } diff_temp[2];
148
149 static int count_lines(const char *data, int size)
150 {
151         int count, ch, completely_empty = 1, nl_just_seen = 0;
152         count = 0;
153         while (0 < size--) {
154                 ch = *data++;
155                 if (ch == '\n') {
156                         count++;
157                         nl_just_seen = 1;
158                         completely_empty = 0;
159                 }
160                 else {
161                         nl_just_seen = 0;
162                         completely_empty = 0;
163                 }
164         }
165         if (completely_empty)
166                 return 0;
167         if (!nl_just_seen)
168                 count++; /* no trailing newline */
169         return count;
170 }
171
172 static void print_line_count(int count)
173 {
174         switch (count) {
175         case 0:
176                 printf("0,0");
177                 break;
178         case 1:
179                 printf("1");
180                 break;
181         default:
182                 printf("1,%d", count);
183                 break;
184         }
185 }
186
187 static void copy_file(int prefix, const char *data, int size,
188                 const char *set, const char *reset)
189 {
190         int ch, nl_just_seen = 1;
191         while (0 < size--) {
192                 ch = *data++;
193                 if (nl_just_seen) {
194                         fputs(set, stdout);
195                         putchar(prefix);
196                 }
197                 if (ch == '\n') {
198                         nl_just_seen = 1;
199                         fputs(reset, stdout);
200                 } else
201                         nl_just_seen = 0;
202                 putchar(ch);
203         }
204         if (!nl_just_seen)
205                 printf("%s\n\\ No newline at end of file\n", reset);
206 }
207
208 static void emit_rewrite_diff(const char *name_a,
209                               const char *name_b,
210                               struct diff_filespec *one,
211                               struct diff_filespec *two,
212                               int color_diff)
213 {
214         int lc_a, lc_b;
215         const char *name_a_tab, *name_b_tab;
216         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
217         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
218         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
219         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
220         const char *reset = diff_get_color(color_diff, DIFF_RESET);
221
222         name_a += (*name_a == '/');
223         name_b += (*name_b == '/');
224         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
225         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
226
227         diff_populate_filespec(one, 0);
228         diff_populate_filespec(two, 0);
229         lc_a = count_lines(one->data, one->size);
230         lc_b = count_lines(two->data, two->size);
231         printf("%s--- a/%s%s%s\n%s+++ b/%s%s%s\n%s@@ -",
232                metainfo, name_a, name_a_tab, reset,
233                metainfo, name_b, name_b_tab, reset, fraginfo);
234         print_line_count(lc_a);
235         printf(" +");
236         print_line_count(lc_b);
237         printf(" @@%s\n", reset);
238         if (lc_a)
239                 copy_file('-', one->data, one->size, old, reset);
240         if (lc_b)
241                 copy_file('+', two->data, two->size, new, reset);
242 }
243
244 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
245 {
246         if (!DIFF_FILE_VALID(one)) {
247                 mf->ptr = (char *)""; /* does not matter */
248                 mf->size = 0;
249                 return 0;
250         }
251         else if (diff_populate_filespec(one, 0))
252                 return -1;
253         mf->ptr = one->data;
254         mf->size = one->size;
255         return 0;
256 }
257
258 struct diff_words_buffer {
259         mmfile_t text;
260         long alloc;
261         long current; /* output pointer */
262         int suppressed_newline;
263 };
264
265 static void diff_words_append(char *line, unsigned long len,
266                 struct diff_words_buffer *buffer)
267 {
268         if (buffer->text.size + len > buffer->alloc) {
269                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
270                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
271         }
272         line++;
273         len--;
274         memcpy(buffer->text.ptr + buffer->text.size, line, len);
275         buffer->text.size += len;
276 }
277
278 struct diff_words_data {
279         struct xdiff_emit_state xm;
280         struct diff_words_buffer minus, plus;
281 };
282
283 static void print_word(struct diff_words_buffer *buffer, int len, int color,
284                 int suppress_newline)
285 {
286         const char *ptr;
287         int eol = 0;
288
289         if (len == 0)
290                 return;
291
292         ptr  = buffer->text.ptr + buffer->current;
293         buffer->current += len;
294
295         if (ptr[len - 1] == '\n') {
296                 eol = 1;
297                 len--;
298         }
299
300         fputs(diff_get_color(1, color), stdout);
301         fwrite(ptr, len, 1, stdout);
302         fputs(diff_get_color(1, DIFF_RESET), stdout);
303
304         if (eol) {
305                 if (suppress_newline)
306                         buffer->suppressed_newline = 1;
307                 else
308                         putchar('\n');
309         }
310 }
311
312 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
313 {
314         struct diff_words_data *diff_words = priv;
315
316         if (diff_words->minus.suppressed_newline) {
317                 if (line[0] != '+')
318                         putchar('\n');
319                 diff_words->minus.suppressed_newline = 0;
320         }
321
322         len--;
323         switch (line[0]) {
324                 case '-':
325                         print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
326                         break;
327                 case '+':
328                         print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
329                         break;
330                 case ' ':
331                         print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
332                         diff_words->minus.current += len;
333                         break;
334         }
335 }
336
337 /* this executes the word diff on the accumulated buffers */
338 static void diff_words_show(struct diff_words_data *diff_words)
339 {
340         xpparam_t xpp;
341         xdemitconf_t xecfg;
342         xdemitcb_t ecb;
343         mmfile_t minus, plus;
344         int i;
345
346         minus.size = diff_words->minus.text.size;
347         minus.ptr = xmalloc(minus.size);
348         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
349         for (i = 0; i < minus.size; i++)
350                 if (isspace(minus.ptr[i]))
351                         minus.ptr[i] = '\n';
352         diff_words->minus.current = 0;
353
354         plus.size = diff_words->plus.text.size;
355         plus.ptr = xmalloc(plus.size);
356         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
357         for (i = 0; i < plus.size; i++)
358                 if (isspace(plus.ptr[i]))
359                         plus.ptr[i] = '\n';
360         diff_words->plus.current = 0;
361
362         xpp.flags = XDF_NEED_MINIMAL;
363         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
364         xecfg.flags = 0;
365         ecb.outf = xdiff_outf;
366         ecb.priv = diff_words;
367         diff_words->xm.consume = fn_out_diff_words_aux;
368         xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
369
370         free(minus.ptr);
371         free(plus.ptr);
372         diff_words->minus.text.size = diff_words->plus.text.size = 0;
373
374         if (diff_words->minus.suppressed_newline) {
375                 putchar('\n');
376                 diff_words->minus.suppressed_newline = 0;
377         }
378 }
379
380 struct emit_callback {
381         struct xdiff_emit_state xm;
382         int nparents, color_diff;
383         const char **label_path;
384         struct diff_words_data *diff_words;
385         int *found_changesp;
386 };
387
388 static void free_diff_words_data(struct emit_callback *ecbdata)
389 {
390         if (ecbdata->diff_words) {
391                 /* flush buffers */
392                 if (ecbdata->diff_words->minus.text.size ||
393                                 ecbdata->diff_words->plus.text.size)
394                         diff_words_show(ecbdata->diff_words);
395
396                 if (ecbdata->diff_words->minus.text.ptr)
397                         free (ecbdata->diff_words->minus.text.ptr);
398                 if (ecbdata->diff_words->plus.text.ptr)
399                         free (ecbdata->diff_words->plus.text.ptr);
400                 free(ecbdata->diff_words);
401                 ecbdata->diff_words = NULL;
402         }
403 }
404
405 const char *diff_get_color(int diff_use_color, enum color_diff ix)
406 {
407         if (diff_use_color)
408                 return diff_colors[ix];
409         return "";
410 }
411
412 static void emit_line(const char *set, const char *reset, const char *line, int len)
413 {
414         if (len > 0 && line[len-1] == '\n')
415                 len--;
416         fputs(set, stdout);
417         fwrite(line, len, 1, stdout);
418         puts(reset);
419 }
420
421 static void emit_line_with_ws(int nparents,
422                 const char *set, const char *reset, const char *ws,
423                 const char *line, int len)
424 {
425         int col0 = nparents;
426         int last_tab_in_indent = -1;
427         int last_space_in_indent = -1;
428         int i;
429         int tail = len;
430         int need_highlight_leading_space = 0;
431         /* The line is a newly added line.  Does it have funny leading
432          * whitespaces?  In indent, SP should never precede a TAB.
433          */
434         for (i = col0; i < len; i++) {
435                 if (line[i] == '\t') {
436                         last_tab_in_indent = i;
437                         if (0 <= last_space_in_indent)
438                                 need_highlight_leading_space = 1;
439                 }
440                 else if (line[i] == ' ')
441                         last_space_in_indent = i;
442                 else
443                         break;
444         }
445         fputs(set, stdout);
446         fwrite(line, col0, 1, stdout);
447         fputs(reset, stdout);
448         if (((i == len) || line[i] == '\n') && i != col0) {
449                 /* The whole line was indent */
450                 emit_line(ws, reset, line + col0, len - col0);
451                 return;
452         }
453         i = col0;
454         if (need_highlight_leading_space) {
455                 while (i < last_tab_in_indent) {
456                         if (line[i] == ' ') {
457                                 fputs(ws, stdout);
458                                 putchar(' ');
459                                 fputs(reset, stdout);
460                         }
461                         else
462                                 putchar(line[i]);
463                         i++;
464                 }
465         }
466         tail = len - 1;
467         if (line[tail] == '\n' && i < tail)
468                 tail--;
469         while (i < tail) {
470                 if (!isspace(line[tail]))
471                         break;
472                 tail--;
473         }
474         if ((i < tail && line[tail + 1] != '\n')) {
475                 /* This has whitespace between tail+1..len */
476                 fputs(set, stdout);
477                 fwrite(line + i, tail - i + 1, 1, stdout);
478                 fputs(reset, stdout);
479                 emit_line(ws, reset, line + tail + 1, len - tail - 1);
480         }
481         else
482                 emit_line(set, reset, line + i, len - i);
483 }
484
485 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
486 {
487         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
488         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
489
490         if (!*ws)
491                 emit_line(set, reset, line, len);
492         else
493                 emit_line_with_ws(ecbdata->nparents, set, reset, ws,
494                                 line, len);
495 }
496
497 static void fn_out_consume(void *priv, char *line, unsigned long len)
498 {
499         int i;
500         int color;
501         struct emit_callback *ecbdata = priv;
502         const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
503         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
504
505         *(ecbdata->found_changesp) = 1;
506
507         if (ecbdata->label_path[0]) {
508                 const char *name_a_tab, *name_b_tab;
509
510                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
511                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
512
513                 printf("%s--- %s%s%s\n",
514                        set, ecbdata->label_path[0], reset, name_a_tab);
515                 printf("%s+++ %s%s%s\n",
516                        set, ecbdata->label_path[1], reset, name_b_tab);
517                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
518         }
519
520         /* This is not really necessary for now because
521          * this codepath only deals with two-way diffs.
522          */
523         for (i = 0; i < len && line[i] == '@'; i++)
524                 ;
525         if (2 <= i && i < len && line[i] == ' ') {
526                 ecbdata->nparents = i - 1;
527                 emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
528                           reset, line, len);
529                 return;
530         }
531
532         if (len < ecbdata->nparents) {
533                 set = reset;
534                 emit_line(reset, reset, line, len);
535                 return;
536         }
537
538         color = DIFF_PLAIN;
539         if (ecbdata->diff_words && ecbdata->nparents != 1)
540                 /* fall back to normal diff */
541                 free_diff_words_data(ecbdata);
542         if (ecbdata->diff_words) {
543                 if (line[0] == '-') {
544                         diff_words_append(line, len,
545                                           &ecbdata->diff_words->minus);
546                         return;
547                 } else if (line[0] == '+') {
548                         diff_words_append(line, len,
549                                           &ecbdata->diff_words->plus);
550                         return;
551                 }
552                 if (ecbdata->diff_words->minus.text.size ||
553                     ecbdata->diff_words->plus.text.size)
554                         diff_words_show(ecbdata->diff_words);
555                 line++;
556                 len--;
557                 emit_line(set, reset, line, len);
558                 return;
559         }
560         for (i = 0; i < ecbdata->nparents && len; i++) {
561                 if (line[i] == '-')
562                         color = DIFF_FILE_OLD;
563                 else if (line[i] == '+')
564                         color = DIFF_FILE_NEW;
565         }
566
567         if (color != DIFF_FILE_NEW) {
568                 emit_line(diff_get_color(ecbdata->color_diff, color),
569                           reset, line, len);
570                 return;
571         }
572         emit_add_line(reset, ecbdata, line, len);
573 }
574
575 static char *pprint_rename(const char *a, const char *b)
576 {
577         const char *old = a;
578         const char *new = b;
579         char *name = NULL;
580         int pfx_length, sfx_length;
581         int len_a = strlen(a);
582         int len_b = strlen(b);
583         int qlen_a = quote_c_style(a, NULL, NULL, 0);
584         int qlen_b = quote_c_style(b, NULL, NULL, 0);
585
586         if (qlen_a || qlen_b) {
587                 if (qlen_a) len_a = qlen_a;
588                 if (qlen_b) len_b = qlen_b;
589                 name = xmalloc( len_a + len_b + 5 );
590                 if (qlen_a)
591                         quote_c_style(a, name, NULL, 0);
592                 else
593                         memcpy(name, a, len_a);
594                 memcpy(name + len_a, " => ", 4);
595                 if (qlen_b)
596                         quote_c_style(b, name + len_a + 4, NULL, 0);
597                 else
598                         memcpy(name + len_a + 4, b, len_b + 1);
599                 return name;
600         }
601
602         /* Find common prefix */
603         pfx_length = 0;
604         while (*old && *new && *old == *new) {
605                 if (*old == '/')
606                         pfx_length = old - a + 1;
607                 old++;
608                 new++;
609         }
610
611         /* Find common suffix */
612         old = a + len_a;
613         new = b + len_b;
614         sfx_length = 0;
615         while (a <= old && b <= new && *old == *new) {
616                 if (*old == '/')
617                         sfx_length = len_a - (old - a);
618                 old--;
619                 new--;
620         }
621
622         /*
623          * pfx{mid-a => mid-b}sfx
624          * {pfx-a => pfx-b}sfx
625          * pfx{sfx-a => sfx-b}
626          * name-a => name-b
627          */
628         if (pfx_length + sfx_length) {
629                 int a_midlen = len_a - pfx_length - sfx_length;
630                 int b_midlen = len_b - pfx_length - sfx_length;
631                 if (a_midlen < 0) a_midlen = 0;
632                 if (b_midlen < 0) b_midlen = 0;
633
634                 name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
635                 sprintf(name, "%.*s{%.*s => %.*s}%s",
636                         pfx_length, a,
637                         a_midlen, a + pfx_length,
638                         b_midlen, b + pfx_length,
639                         a + len_a - sfx_length);
640         }
641         else {
642                 name = xmalloc(len_a + len_b + 5);
643                 sprintf(name, "%s => %s", a, b);
644         }
645         return name;
646 }
647
648 struct diffstat_t {
649         struct xdiff_emit_state xm;
650
651         int nr;
652         int alloc;
653         struct diffstat_file {
654                 char *name;
655                 unsigned is_unmerged:1;
656                 unsigned is_binary:1;
657                 unsigned is_renamed:1;
658                 unsigned int added, deleted;
659         } **files;
660 };
661
662 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
663                                           const char *name_a,
664                                           const char *name_b)
665 {
666         struct diffstat_file *x;
667         x = xcalloc(sizeof (*x), 1);
668         if (diffstat->nr == diffstat->alloc) {
669                 diffstat->alloc = alloc_nr(diffstat->alloc);
670                 diffstat->files = xrealloc(diffstat->files,
671                                 diffstat->alloc * sizeof(x));
672         }
673         diffstat->files[diffstat->nr++] = x;
674         if (name_b) {
675                 x->name = pprint_rename(name_a, name_b);
676                 x->is_renamed = 1;
677         }
678         else
679                 x->name = xstrdup(name_a);
680         return x;
681 }
682
683 static void diffstat_consume(void *priv, char *line, unsigned long len)
684 {
685         struct diffstat_t *diffstat = priv;
686         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
687
688         if (line[0] == '+')
689                 x->added++;
690         else if (line[0] == '-')
691                 x->deleted++;
692 }
693
694 const char mime_boundary_leader[] = "------------";
695
696 static int scale_linear(int it, int width, int max_change)
697 {
698         /*
699          * make sure that at least one '-' is printed if there were deletions,
700          * and likewise for '+'.
701          */
702         if (max_change < 2)
703                 return it;
704         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
705 }
706
707 static void show_name(const char *prefix, const char *name, int len,
708                       const char *reset, const char *set)
709 {
710         printf(" %s%s%-*s%s |", set, prefix, len, name, reset);
711 }
712
713 static void show_graph(char ch, int cnt, const char *set, const char *reset)
714 {
715         if (cnt <= 0)
716                 return;
717         printf("%s", set);
718         while (cnt--)
719                 putchar(ch);
720         printf("%s", reset);
721 }
722
723 static void show_stats(struct diffstat_t* data, struct diff_options *options)
724 {
725         int i, len, add, del, total, adds = 0, dels = 0;
726         int max_change = 0, max_len = 0;
727         int total_files = data->nr;
728         int width, name_width;
729         const char *reset, *set, *add_c, *del_c;
730
731         if (data->nr == 0)
732                 return;
733
734         width = options->stat_width ? options->stat_width : 80;
735         name_width = options->stat_name_width ? options->stat_name_width : 50;
736
737         /* Sanity: give at least 5 columns to the graph,
738          * but leave at least 10 columns for the name.
739          */
740         if (width < name_width + 15) {
741                 if (name_width <= 25)
742                         width = name_width + 15;
743                 else
744                         name_width = width - 15;
745         }
746
747         /* Find the longest filename and max number of changes */
748         reset = diff_get_color(options->color_diff, DIFF_RESET);
749         set = diff_get_color(options->color_diff, DIFF_PLAIN);
750         add_c = diff_get_color(options->color_diff, DIFF_FILE_NEW);
751         del_c = diff_get_color(options->color_diff, DIFF_FILE_OLD);
752
753         for (i = 0; i < data->nr; i++) {
754                 struct diffstat_file *file = data->files[i];
755                 int change = file->added + file->deleted;
756
757                 if (!file->is_renamed) {  /* renames are already quoted by pprint_rename */
758                         len = quote_c_style(file->name, NULL, NULL, 0);
759                         if (len) {
760                                 char *qname = xmalloc(len + 1);
761                                 quote_c_style(file->name, qname, NULL, 0);
762                                 free(file->name);
763                                 file->name = qname;
764                         }
765                 }
766
767                 len = strlen(file->name);
768                 if (max_len < len)
769                         max_len = len;
770
771                 if (file->is_binary || file->is_unmerged)
772                         continue;
773                 if (max_change < change)
774                         max_change = change;
775         }
776
777         /* Compute the width of the graph part;
778          * 10 is for one blank at the beginning of the line plus
779          * " | count " between the name and the graph.
780          *
781          * From here on, name_width is the width of the name area,
782          * and width is the width of the graph area.
783          */
784         name_width = (name_width < max_len) ? name_width : max_len;
785         if (width < (name_width + 10) + max_change)
786                 width = width - (name_width + 10);
787         else
788                 width = max_change;
789
790         for (i = 0; i < data->nr; i++) {
791                 const char *prefix = "";
792                 char *name = data->files[i]->name;
793                 int added = data->files[i]->added;
794                 int deleted = data->files[i]->deleted;
795                 int name_len;
796
797                 /*
798                  * "scale" the filename
799                  */
800                 len = name_width;
801                 name_len = strlen(name);
802                 if (name_width < name_len) {
803                         char *slash;
804                         prefix = "...";
805                         len -= 3;
806                         name += name_len - len;
807                         slash = strchr(name, '/');
808                         if (slash)
809                                 name = slash;
810                 }
811
812                 if (data->files[i]->is_binary) {
813                         show_name(prefix, name, len, reset, set);
814                         printf("  Bin ");
815                         printf("%s%d%s", del_c, deleted, reset);
816                         printf(" -> ");
817                         printf("%s%d%s", add_c, added, reset);
818                         printf(" bytes");
819                         printf("\n");
820                         goto free_diffstat_file;
821                 }
822                 else if (data->files[i]->is_unmerged) {
823                         show_name(prefix, name, len, reset, set);
824                         printf("  Unmerged\n");
825                         goto free_diffstat_file;
826                 }
827                 else if (!data->files[i]->is_renamed &&
828                          (added + deleted == 0)) {
829                         total_files--;
830                         goto free_diffstat_file;
831                 }
832
833                 /*
834                  * scale the add/delete
835                  */
836                 add = added;
837                 del = deleted;
838                 total = add + del;
839                 adds += add;
840                 dels += del;
841
842                 if (width <= max_change) {
843                         add = scale_linear(add, width, max_change);
844                         del = scale_linear(del, width, max_change);
845                         total = add + del;
846                 }
847                 show_name(prefix, name, len, reset, set);
848                 printf("%5d ", added + deleted);
849                 show_graph('+', add, add_c, reset);
850                 show_graph('-', del, del_c, reset);
851                 putchar('\n');
852         free_diffstat_file:
853                 free(data->files[i]->name);
854                 free(data->files[i]);
855         }
856         free(data->files);
857         printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
858                set, total_files, adds, dels, reset);
859 }
860
861 static void show_shortstats(struct diffstat_t* data)
862 {
863         int i, adds = 0, dels = 0, total_files = data->nr;
864
865         if (data->nr == 0)
866                 return;
867
868         for (i = 0; i < data->nr; i++) {
869                 if (!data->files[i]->is_binary &&
870                     !data->files[i]->is_unmerged) {
871                         int added = data->files[i]->added;
872                         int deleted= data->files[i]->deleted;
873                         if (!data->files[i]->is_renamed &&
874                             (added + deleted == 0)) {
875                                 total_files--;
876                         } else {
877                                 adds += added;
878                                 dels += deleted;
879                         }
880                 }
881                 free(data->files[i]->name);
882                 free(data->files[i]);
883         }
884         free(data->files);
885
886         printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
887                total_files, adds, dels);
888 }
889
890 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
891 {
892         int i;
893
894         for (i = 0; i < data->nr; i++) {
895                 struct diffstat_file *file = data->files[i];
896
897                 if (file->is_binary)
898                         printf("-\t-\t");
899                 else
900                         printf("%d\t%d\t", file->added, file->deleted);
901                 if (options->line_termination && !file->is_renamed &&
902                     quote_c_style(file->name, NULL, NULL, 0))
903                         quote_c_style(file->name, NULL, stdout, 0);
904                 else
905                         fputs(file->name, stdout);
906                 putchar(options->line_termination);
907         }
908 }
909
910 struct checkdiff_t {
911         struct xdiff_emit_state xm;
912         const char *filename;
913         int lineno, color_diff;
914 };
915
916 static void checkdiff_consume(void *priv, char *line, unsigned long len)
917 {
918         struct checkdiff_t *data = priv;
919         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
920         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
921         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
922
923         if (line[0] == '+') {
924                 int i, spaces = 0, space_before_tab = 0, white_space_at_end = 0;
925
926                 /* check space before tab */
927                 for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
928                         if (line[i] == ' ')
929                                 spaces++;
930                 if (line[i - 1] == '\t' && spaces)
931                         space_before_tab = 1;
932
933                 /* check white space at line end */
934                 if (line[len - 1] == '\n')
935                         len--;
936                 if (isspace(line[len - 1]))
937                         white_space_at_end = 1;
938
939                 if (space_before_tab || white_space_at_end) {
940                         printf("%s:%d: %s", data->filename, data->lineno, ws);
941                         if (space_before_tab) {
942                                 printf("space before tab");
943                                 if (white_space_at_end)
944                                         putchar(',');
945                         }
946                         if (white_space_at_end)
947                                 printf("white space at end");
948                         printf(":%s ", reset);
949                         emit_line_with_ws(1, set, reset, ws, line, len);
950                 }
951
952                 data->lineno++;
953         } else if (line[0] == ' ')
954                 data->lineno++;
955         else if (line[0] == '@') {
956                 char *plus = strchr(line, '+');
957                 if (plus)
958                         data->lineno = strtol(plus, NULL, 10);
959                 else
960                         die("invalid diff");
961         }
962 }
963
964 static unsigned char *deflate_it(char *data,
965                                  unsigned long size,
966                                  unsigned long *result_size)
967 {
968         int bound;
969         unsigned char *deflated;
970         z_stream stream;
971
972         memset(&stream, 0, sizeof(stream));
973         deflateInit(&stream, zlib_compression_level);
974         bound = deflateBound(&stream, size);
975         deflated = xmalloc(bound);
976         stream.next_out = deflated;
977         stream.avail_out = bound;
978
979         stream.next_in = (unsigned char *)data;
980         stream.avail_in = size;
981         while (deflate(&stream, Z_FINISH) == Z_OK)
982                 ; /* nothing */
983         deflateEnd(&stream);
984         *result_size = stream.total_out;
985         return deflated;
986 }
987
988 static void emit_binary_diff_body(mmfile_t *one, mmfile_t *two)
989 {
990         void *cp;
991         void *delta;
992         void *deflated;
993         void *data;
994         unsigned long orig_size;
995         unsigned long delta_size;
996         unsigned long deflate_size;
997         unsigned long data_size;
998
999         /* We could do deflated delta, or we could do just deflated two,
1000          * whichever is smaller.
1001          */
1002         delta = NULL;
1003         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1004         if (one->size && two->size) {
1005                 delta = diff_delta(one->ptr, one->size,
1006                                    two->ptr, two->size,
1007                                    &delta_size, deflate_size);
1008                 if (delta) {
1009                         void *to_free = delta;
1010                         orig_size = delta_size;
1011                         delta = deflate_it(delta, delta_size, &delta_size);
1012                         free(to_free);
1013                 }
1014         }
1015
1016         if (delta && delta_size < deflate_size) {
1017                 printf("delta %lu\n", orig_size);
1018                 free(deflated);
1019                 data = delta;
1020                 data_size = delta_size;
1021         }
1022         else {
1023                 printf("literal %lu\n", two->size);
1024                 free(delta);
1025                 data = deflated;
1026                 data_size = deflate_size;
1027         }
1028
1029         /* emit data encoded in base85 */
1030         cp = data;
1031         while (data_size) {
1032                 int bytes = (52 < data_size) ? 52 : data_size;
1033                 char line[70];
1034                 data_size -= bytes;
1035                 if (bytes <= 26)
1036                         line[0] = bytes + 'A' - 1;
1037                 else
1038                         line[0] = bytes - 26 + 'a' - 1;
1039                 encode_85(line + 1, cp, bytes);
1040                 cp = (char *) cp + bytes;
1041                 puts(line);
1042         }
1043         printf("\n");
1044         free(data);
1045 }
1046
1047 static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
1048 {
1049         printf("GIT binary patch\n");
1050         emit_binary_diff_body(one, two);
1051         emit_binary_diff_body(two, one);
1052 }
1053
1054 #define FIRST_FEW_BYTES 8000
1055 static int mmfile_is_binary(mmfile_t *mf)
1056 {
1057         long sz = mf->size;
1058         if (FIRST_FEW_BYTES < sz)
1059                 sz = FIRST_FEW_BYTES;
1060         return !!memchr(mf->ptr, 0, sz);
1061 }
1062
1063 static void builtin_diff(const char *name_a,
1064                          const char *name_b,
1065                          struct diff_filespec *one,
1066                          struct diff_filespec *two,
1067                          const char *xfrm_msg,
1068                          struct diff_options *o,
1069                          int complete_rewrite)
1070 {
1071         mmfile_t mf1, mf2;
1072         const char *lbl[2];
1073         char *a_one, *b_two;
1074         const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
1075         const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
1076
1077         a_one = quote_two("a/", name_a + (*name_a == '/'));
1078         b_two = quote_two("b/", name_b + (*name_b == '/'));
1079         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1080         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1081         printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1082         if (lbl[0][0] == '/') {
1083                 /* /dev/null */
1084                 printf("%snew file mode %06o%s\n", set, two->mode, reset);
1085                 if (xfrm_msg && xfrm_msg[0])
1086                         printf("%s%s%s\n", set, xfrm_msg, reset);
1087         }
1088         else if (lbl[1][0] == '/') {
1089                 printf("%sdeleted file mode %06o%s\n", set, one->mode, reset);
1090                 if (xfrm_msg && xfrm_msg[0])
1091                         printf("%s%s%s\n", set, xfrm_msg, reset);
1092         }
1093         else {
1094                 if (one->mode != two->mode) {
1095                         printf("%sold mode %06o%s\n", set, one->mode, reset);
1096                         printf("%snew mode %06o%s\n", set, two->mode, reset);
1097                 }
1098                 if (xfrm_msg && xfrm_msg[0])
1099                         printf("%s%s%s\n", set, xfrm_msg, reset);
1100                 /*
1101                  * we do not run diff between different kind
1102                  * of objects.
1103                  */
1104                 if ((one->mode ^ two->mode) & S_IFMT)
1105                         goto free_ab_and_return;
1106                 if (complete_rewrite) {
1107                         emit_rewrite_diff(name_a, name_b, one, two,
1108                                         o->color_diff);
1109                         o->found_changes = 1;
1110                         goto free_ab_and_return;
1111                 }
1112         }
1113
1114         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1115                 die("unable to read files to diff");
1116
1117         if (!o->text && (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))) {
1118                 /* Quite common confusing case */
1119                 if (mf1.size == mf2.size &&
1120                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1121                         goto free_ab_and_return;
1122                 if (o->binary)
1123                         emit_binary_diff(&mf1, &mf2);
1124                 else
1125                         printf("Binary files %s and %s differ\n",
1126                                lbl[0], lbl[1]);
1127                 o->found_changes = 1;
1128         }
1129         else {
1130                 /* Crazy xdl interfaces.. */
1131                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1132                 xpparam_t xpp;
1133                 xdemitconf_t xecfg;
1134                 xdemitcb_t ecb;
1135                 struct emit_callback ecbdata;
1136
1137                 memset(&ecbdata, 0, sizeof(ecbdata));
1138                 ecbdata.label_path = lbl;
1139                 ecbdata.color_diff = o->color_diff;
1140                 ecbdata.found_changesp = &o->found_changes;
1141                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1142                 xecfg.ctxlen = o->context;
1143                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1144                 if (!diffopts)
1145                         ;
1146                 else if (!prefixcmp(diffopts, "--unified="))
1147                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1148                 else if (!prefixcmp(diffopts, "-u"))
1149                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1150                 ecb.outf = xdiff_outf;
1151                 ecb.priv = &ecbdata;
1152                 ecbdata.xm.consume = fn_out_consume;
1153                 if (o->color_diff_words)
1154                         ecbdata.diff_words =
1155                                 xcalloc(1, sizeof(struct diff_words_data));
1156                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1157                 if (o->color_diff_words)
1158                         free_diff_words_data(&ecbdata);
1159         }
1160
1161  free_ab_and_return:
1162         free(a_one);
1163         free(b_two);
1164         return;
1165 }
1166
1167 static void builtin_diffstat(const char *name_a, const char *name_b,
1168                              struct diff_filespec *one,
1169                              struct diff_filespec *two,
1170                              struct diffstat_t *diffstat,
1171                              struct diff_options *o,
1172                              int complete_rewrite)
1173 {
1174         mmfile_t mf1, mf2;
1175         struct diffstat_file *data;
1176
1177         data = diffstat_add(diffstat, name_a, name_b);
1178
1179         if (!one || !two) {
1180                 data->is_unmerged = 1;
1181                 return;
1182         }
1183         if (complete_rewrite) {
1184                 diff_populate_filespec(one, 0);
1185                 diff_populate_filespec(two, 0);
1186                 data->deleted = count_lines(one->data, one->size);
1187                 data->added = count_lines(two->data, two->size);
1188                 return;
1189         }
1190         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1191                 die("unable to read files to diff");
1192
1193         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
1194                 data->is_binary = 1;
1195                 data->added = mf2.size;
1196                 data->deleted = mf1.size;
1197         } else {
1198                 /* Crazy xdl interfaces.. */
1199                 xpparam_t xpp;
1200                 xdemitconf_t xecfg;
1201                 xdemitcb_t ecb;
1202
1203                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1204                 xecfg.ctxlen = 0;
1205                 xecfg.flags = 0;
1206                 ecb.outf = xdiff_outf;
1207                 ecb.priv = diffstat;
1208                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1209         }
1210 }
1211
1212 static void builtin_checkdiff(const char *name_a, const char *name_b,
1213                              struct diff_filespec *one,
1214                              struct diff_filespec *two, struct diff_options *o)
1215 {
1216         mmfile_t mf1, mf2;
1217         struct checkdiff_t data;
1218
1219         if (!two)
1220                 return;
1221
1222         memset(&data, 0, sizeof(data));
1223         data.xm.consume = checkdiff_consume;
1224         data.filename = name_b ? name_b : name_a;
1225         data.lineno = 0;
1226         data.color_diff = o->color_diff;
1227
1228         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1229                 die("unable to read files to diff");
1230
1231         if (mmfile_is_binary(&mf2))
1232                 return;
1233         else {
1234                 /* Crazy xdl interfaces.. */
1235                 xpparam_t xpp;
1236                 xdemitconf_t xecfg;
1237                 xdemitcb_t ecb;
1238
1239                 xpp.flags = XDF_NEED_MINIMAL;
1240                 xecfg.ctxlen = 0;
1241                 xecfg.flags = 0;
1242                 ecb.outf = xdiff_outf;
1243                 ecb.priv = &data;
1244                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1245         }
1246 }
1247
1248 struct diff_filespec *alloc_filespec(const char *path)
1249 {
1250         int namelen = strlen(path);
1251         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1252
1253         memset(spec, 0, sizeof(*spec));
1254         spec->path = (char *)(spec + 1);
1255         memcpy(spec->path, path, namelen+1);
1256         return spec;
1257 }
1258
1259 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1260                    unsigned short mode)
1261 {
1262         if (mode) {
1263                 spec->mode = canon_mode(mode);
1264                 hashcpy(spec->sha1, sha1);
1265                 spec->sha1_valid = !is_null_sha1(sha1);
1266         }
1267 }
1268
1269 /*
1270  * Given a name and sha1 pair, if the dircache tells us the file in
1271  * the work tree has that object contents, return true, so that
1272  * prepare_temp_file() does not have to inflate and extract.
1273  */
1274 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1275 {
1276         struct cache_entry *ce;
1277         struct stat st;
1278         int pos, len;
1279
1280         /* We do not read the cache ourselves here, because the
1281          * benchmark with my previous version that always reads cache
1282          * shows that it makes things worse for diff-tree comparing
1283          * two linux-2.6 kernel trees in an already checked out work
1284          * tree.  This is because most diff-tree comparisons deal with
1285          * only a small number of files, while reading the cache is
1286          * expensive for a large project, and its cost outweighs the
1287          * savings we get by not inflating the object to a temporary
1288          * file.  Practically, this code only helps when we are used
1289          * by diff-cache --cached, which does read the cache before
1290          * calling us.
1291          */
1292         if (!active_cache)
1293                 return 0;
1294
1295         /* We want to avoid the working directory if our caller
1296          * doesn't need the data in a normal file, this system
1297          * is rather slow with its stat/open/mmap/close syscalls,
1298          * and the object is contained in a pack file.  The pack
1299          * is probably already open and will be faster to obtain
1300          * the data through than the working directory.  Loose
1301          * objects however would tend to be slower as they need
1302          * to be individually opened and inflated.
1303          */
1304         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1305                 return 0;
1306
1307         len = strlen(name);
1308         pos = cache_name_pos(name, len);
1309         if (pos < 0)
1310                 return 0;
1311         ce = active_cache[pos];
1312         if ((lstat(name, &st) < 0) ||
1313             !S_ISREG(st.st_mode) || /* careful! */
1314             ce_match_stat(ce, &st, 0) ||
1315             hashcmp(sha1, ce->sha1))
1316                 return 0;
1317         /* we return 1 only when we can stat, it is a regular file,
1318          * stat information matches, and sha1 recorded in the cache
1319          * matches.  I.e. we know the file in the work tree really is
1320          * the same as the <name, sha1> pair.
1321          */
1322         return 1;
1323 }
1324
1325 static struct sha1_size_cache {
1326         unsigned char sha1[20];
1327         unsigned long size;
1328 } **sha1_size_cache;
1329 static int sha1_size_cache_nr, sha1_size_cache_alloc;
1330
1331 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
1332                                                  int find_only,
1333                                                  unsigned long size)
1334 {
1335         int first, last;
1336         struct sha1_size_cache *e;
1337
1338         first = 0;
1339         last = sha1_size_cache_nr;
1340         while (last > first) {
1341                 int cmp, next = (last + first) >> 1;
1342                 e = sha1_size_cache[next];
1343                 cmp = hashcmp(e->sha1, sha1);
1344                 if (!cmp)
1345                         return e;
1346                 if (cmp < 0) {
1347                         last = next;
1348                         continue;
1349                 }
1350                 first = next+1;
1351         }
1352         /* not found */
1353         if (find_only)
1354                 return NULL;
1355         /* insert to make it at "first" */
1356         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
1357                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
1358                 sha1_size_cache = xrealloc(sha1_size_cache,
1359                                            sha1_size_cache_alloc *
1360                                            sizeof(*sha1_size_cache));
1361         }
1362         sha1_size_cache_nr++;
1363         if (first < sha1_size_cache_nr)
1364                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
1365                         (sha1_size_cache_nr - first - 1) *
1366                         sizeof(*sha1_size_cache));
1367         e = xmalloc(sizeof(struct sha1_size_cache));
1368         sha1_size_cache[first] = e;
1369         hashcpy(e->sha1, sha1);
1370         e->size = size;
1371         return e;
1372 }
1373
1374 static int populate_from_stdin(struct diff_filespec *s)
1375 {
1376 #define INCREMENT 1024
1377         char *buf;
1378         unsigned long size;
1379         int got;
1380
1381         size = 0;
1382         buf = NULL;
1383         while (1) {
1384                 buf = xrealloc(buf, size + INCREMENT);
1385                 got = xread(0, buf + size, INCREMENT);
1386                 if (!got)
1387                         break; /* EOF */
1388                 if (got < 0)
1389                         return error("error while reading from stdin %s",
1390                                      strerror(errno));
1391                 size += got;
1392         }
1393         s->should_munmap = 0;
1394         s->data = buf;
1395         s->size = size;
1396         s->should_free = 1;
1397         return 0;
1398 }
1399
1400 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1401 {
1402         int len;
1403         char *data = xmalloc(100);
1404         len = snprintf(data, 100,
1405                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1406         s->data = data;
1407         s->size = len;
1408         s->should_free = 1;
1409         if (size_only) {
1410                 s->data = NULL;
1411                 free(data);
1412         }
1413         return 0;
1414 }
1415
1416 /*
1417  * While doing rename detection and pickaxe operation, we may need to
1418  * grab the data for the blob (or file) for our own in-core comparison.
1419  * diff_filespec has data and size fields for this purpose.
1420  */
1421 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1422 {
1423         int err = 0;
1424         if (!DIFF_FILE_VALID(s))
1425                 die("internal error: asking to populate invalid file.");
1426         if (S_ISDIR(s->mode))
1427                 return -1;
1428
1429         if (!use_size_cache)
1430                 size_only = 0;
1431
1432         if (s->data)
1433                 return err;
1434
1435         if (S_ISDIRLNK(s->mode))
1436                 return diff_populate_gitlink(s, size_only);
1437
1438         if (!s->sha1_valid ||
1439             reuse_worktree_file(s->path, s->sha1, 0)) {
1440                 struct stat st;
1441                 int fd;
1442                 char *buf;
1443                 unsigned long size;
1444
1445                 if (!strcmp(s->path, "-"))
1446                         return populate_from_stdin(s);
1447
1448                 if (lstat(s->path, &st) < 0) {
1449                         if (errno == ENOENT) {
1450                         err_empty:
1451                                 err = -1;
1452                         empty:
1453                                 s->data = (char *)"";
1454                                 s->size = 0;
1455                                 return err;
1456                         }
1457                 }
1458                 s->size = xsize_t(st.st_size);
1459                 if (!s->size)
1460                         goto empty;
1461                 if (size_only)
1462                         return 0;
1463                 if (S_ISLNK(st.st_mode)) {
1464                         int ret;
1465                         s->data = xmalloc(s->size);
1466                         s->should_free = 1;
1467                         ret = readlink(s->path, s->data, s->size);
1468                         if (ret < 0) {
1469                                 free(s->data);
1470                                 goto err_empty;
1471                         }
1472                         return 0;
1473                 }
1474                 fd = open(s->path, O_RDONLY);
1475                 if (fd < 0)
1476                         goto err_empty;
1477                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1478                 close(fd);
1479                 s->should_munmap = 1;
1480
1481                 /*
1482                  * Convert from working tree format to canonical git format
1483                  */
1484                 buf = s->data;
1485                 size = s->size;
1486                 if (convert_to_git(s->path, &buf, &size)) {
1487                         munmap(s->data, s->size);
1488                         s->should_munmap = 0;
1489                         s->data = buf;
1490                         s->size = size;
1491                         s->should_free = 1;
1492                 }
1493         }
1494         else {
1495                 enum object_type type;
1496                 struct sha1_size_cache *e;
1497
1498                 if (size_only) {
1499                         e = locate_size_cache(s->sha1, 1, 0);
1500                         if (e) {
1501                                 s->size = e->size;
1502                                 return 0;
1503                         }
1504                         type = sha1_object_info(s->sha1, &s->size);
1505                         if (type < 0)
1506                                 locate_size_cache(s->sha1, 0, s->size);
1507                 }
1508                 else {
1509                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1510                         s->should_free = 1;
1511                 }
1512         }
1513         return 0;
1514 }
1515
1516 void diff_free_filespec_data(struct diff_filespec *s)
1517 {
1518         if (s->should_free)
1519                 free(s->data);
1520         else if (s->should_munmap)
1521                 munmap(s->data, s->size);
1522         s->should_free = s->should_munmap = 0;
1523         s->data = NULL;
1524         free(s->cnt_data);
1525         s->cnt_data = NULL;
1526 }
1527
1528 static void prep_temp_blob(struct diff_tempfile *temp,
1529                            void *blob,
1530                            unsigned long size,
1531                            const unsigned char *sha1,
1532                            int mode)
1533 {
1534         int fd;
1535
1536         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
1537         if (fd < 0)
1538                 die("unable to create temp-file");
1539         if (write_in_full(fd, blob, size) != size)
1540                 die("unable to write temp-file");
1541         close(fd);
1542         temp->name = temp->tmp_path;
1543         strcpy(temp->hex, sha1_to_hex(sha1));
1544         temp->hex[40] = 0;
1545         sprintf(temp->mode, "%06o", mode);
1546 }
1547
1548 static void prepare_temp_file(const char *name,
1549                               struct diff_tempfile *temp,
1550                               struct diff_filespec *one)
1551 {
1552         if (!DIFF_FILE_VALID(one)) {
1553         not_a_valid_file:
1554                 /* A '-' entry produces this for file-2, and
1555                  * a '+' entry produces this for file-1.
1556                  */
1557                 temp->name = "/dev/null";
1558                 strcpy(temp->hex, ".");
1559                 strcpy(temp->mode, ".");
1560                 return;
1561         }
1562
1563         if (!one->sha1_valid ||
1564             reuse_worktree_file(name, one->sha1, 1)) {
1565                 struct stat st;
1566                 if (lstat(name, &st) < 0) {
1567                         if (errno == ENOENT)
1568                                 goto not_a_valid_file;
1569                         die("stat(%s): %s", name, strerror(errno));
1570                 }
1571                 if (S_ISLNK(st.st_mode)) {
1572                         int ret;
1573                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1574                         size_t sz = xsize_t(st.st_size);
1575                         if (sizeof(buf) <= st.st_size)
1576                                 die("symlink too long: %s", name);
1577                         ret = readlink(name, buf, sz);
1578                         if (ret < 0)
1579                                 die("readlink(%s)", name);
1580                         prep_temp_blob(temp, buf, sz,
1581                                        (one->sha1_valid ?
1582                                         one->sha1 : null_sha1),
1583                                        (one->sha1_valid ?
1584                                         one->mode : S_IFLNK));
1585                 }
1586                 else {
1587                         /* we can borrow from the file in the work tree */
1588                         temp->name = name;
1589                         if (!one->sha1_valid)
1590                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1591                         else
1592                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1593                         /* Even though we may sometimes borrow the
1594                          * contents from the work tree, we always want
1595                          * one->mode.  mode is trustworthy even when
1596                          * !(one->sha1_valid), as long as
1597                          * DIFF_FILE_VALID(one).
1598                          */
1599                         sprintf(temp->mode, "%06o", one->mode);
1600                 }
1601                 return;
1602         }
1603         else {
1604                 if (diff_populate_filespec(one, 0))
1605                         die("cannot read data blob for %s", one->path);
1606                 prep_temp_blob(temp, one->data, one->size,
1607                                one->sha1, one->mode);
1608         }
1609 }
1610
1611 static void remove_tempfile(void)
1612 {
1613         int i;
1614
1615         for (i = 0; i < 2; i++)
1616                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1617                         unlink(diff_temp[i].name);
1618                         diff_temp[i].name = NULL;
1619                 }
1620 }
1621
1622 static void remove_tempfile_on_signal(int signo)
1623 {
1624         remove_tempfile();
1625         signal(SIGINT, SIG_DFL);
1626         raise(signo);
1627 }
1628
1629 static int spawn_prog(const char *pgm, const char **arg)
1630 {
1631         pid_t pid;
1632         int status;
1633
1634         fflush(NULL);
1635         pid = fork();
1636         if (pid < 0)
1637                 die("unable to fork");
1638         if (!pid) {
1639                 execvp(pgm, (char *const*) arg);
1640                 exit(255);
1641         }
1642
1643         while (waitpid(pid, &status, 0) < 0) {
1644                 if (errno == EINTR)
1645                         continue;
1646                 return -1;
1647         }
1648
1649         /* Earlier we did not check the exit status because
1650          * diff exits non-zero if files are different, and
1651          * we are not interested in knowing that.  It was a
1652          * mistake which made it harder to quit a diff-*
1653          * session that uses the git-apply-patch-script as
1654          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
1655          * should also exit non-zero only when it wants to
1656          * abort the entire diff-* session.
1657          */
1658         if (WIFEXITED(status) && !WEXITSTATUS(status))
1659                 return 0;
1660         return -1;
1661 }
1662
1663 /* An external diff command takes:
1664  *
1665  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1666  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1667  *
1668  */
1669 static void run_external_diff(const char *pgm,
1670                               const char *name,
1671                               const char *other,
1672                               struct diff_filespec *one,
1673                               struct diff_filespec *two,
1674                               const char *xfrm_msg,
1675                               int complete_rewrite)
1676 {
1677         const char *spawn_arg[10];
1678         struct diff_tempfile *temp = diff_temp;
1679         int retval;
1680         static int atexit_asked = 0;
1681         const char *othername;
1682         const char **arg = &spawn_arg[0];
1683
1684         othername = (other? other : name);
1685         if (one && two) {
1686                 prepare_temp_file(name, &temp[0], one);
1687                 prepare_temp_file(othername, &temp[1], two);
1688                 if (! atexit_asked &&
1689                     (temp[0].name == temp[0].tmp_path ||
1690                      temp[1].name == temp[1].tmp_path)) {
1691                         atexit_asked = 1;
1692                         atexit(remove_tempfile);
1693                 }
1694                 signal(SIGINT, remove_tempfile_on_signal);
1695         }
1696
1697         if (one && two) {
1698                 *arg++ = pgm;
1699                 *arg++ = name;
1700                 *arg++ = temp[0].name;
1701                 *arg++ = temp[0].hex;
1702                 *arg++ = temp[0].mode;
1703                 *arg++ = temp[1].name;
1704                 *arg++ = temp[1].hex;
1705                 *arg++ = temp[1].mode;
1706                 if (other) {
1707                         *arg++ = other;
1708                         *arg++ = xfrm_msg;
1709                 }
1710         } else {
1711                 *arg++ = pgm;
1712                 *arg++ = name;
1713         }
1714         *arg = NULL;
1715         retval = spawn_prog(pgm, spawn_arg);
1716         remove_tempfile();
1717         if (retval) {
1718                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1719                 exit(1);
1720         }
1721 }
1722
1723 static void run_diff_cmd(const char *pgm,
1724                          const char *name,
1725                          const char *other,
1726                          struct diff_filespec *one,
1727                          struct diff_filespec *two,
1728                          const char *xfrm_msg,
1729                          struct diff_options *o,
1730                          int complete_rewrite)
1731 {
1732         if (pgm) {
1733                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1734                                   complete_rewrite);
1735                 return;
1736         }
1737         if (one && two)
1738                 builtin_diff(name, other ? other : name,
1739                              one, two, xfrm_msg, o, complete_rewrite);
1740         else
1741                 printf("* Unmerged path %s\n", name);
1742 }
1743
1744 static void diff_fill_sha1_info(struct diff_filespec *one)
1745 {
1746         if (DIFF_FILE_VALID(one)) {
1747                 if (!one->sha1_valid) {
1748                         struct stat st;
1749                         if (!strcmp(one->path, "-")) {
1750                                 hashcpy(one->sha1, null_sha1);
1751                                 return;
1752                         }
1753                         if (lstat(one->path, &st) < 0)
1754                                 die("stat %s", one->path);
1755                         if (index_path(one->sha1, one->path, &st, 0))
1756                                 die("cannot hash %s\n", one->path);
1757                 }
1758         }
1759         else
1760                 hashclr(one->sha1);
1761 }
1762
1763 static void run_diff(struct diff_filepair *p, struct diff_options *o)
1764 {
1765         const char *pgm = external_diff();
1766         char msg[PATH_MAX*2+300], *xfrm_msg;
1767         struct diff_filespec *one;
1768         struct diff_filespec *two;
1769         const char *name;
1770         const char *other;
1771         char *name_munged, *other_munged;
1772         int complete_rewrite = 0;
1773         int len;
1774
1775         if (DIFF_PAIR_UNMERGED(p)) {
1776                 /* unmerged */
1777                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1778                 return;
1779         }
1780
1781         name = p->one->path;
1782         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1783         name_munged = quote_one(name);
1784         other_munged = quote_one(other);
1785         one = p->one; two = p->two;
1786
1787         diff_fill_sha1_info(one);
1788         diff_fill_sha1_info(two);
1789
1790         len = 0;
1791         switch (p->status) {
1792         case DIFF_STATUS_COPIED:
1793                 len += snprintf(msg + len, sizeof(msg) - len,
1794                                 "similarity index %d%%\n"
1795                                 "copy from %s\n"
1796                                 "copy to %s\n",
1797                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1798                                 name_munged, other_munged);
1799                 break;
1800         case DIFF_STATUS_RENAMED:
1801                 len += snprintf(msg + len, sizeof(msg) - len,
1802                                 "similarity index %d%%\n"
1803                                 "rename from %s\n"
1804                                 "rename to %s\n",
1805                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
1806                                 name_munged, other_munged);
1807                 break;
1808         case DIFF_STATUS_MODIFIED:
1809                 if (p->score) {
1810                         len += snprintf(msg + len, sizeof(msg) - len,
1811                                         "dissimilarity index %d%%\n",
1812                                         (int)(0.5 + p->score *
1813                                               100.0/MAX_SCORE));
1814                         complete_rewrite = 1;
1815                         break;
1816                 }
1817                 /* fallthru */
1818         default:
1819                 /* nothing */
1820                 ;
1821         }
1822
1823         if (hashcmp(one->sha1, two->sha1)) {
1824                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1825
1826                 if (o->binary) {
1827                         mmfile_t mf;
1828                         if ((!fill_mmfile(&mf, one) && mmfile_is_binary(&mf)) ||
1829                             (!fill_mmfile(&mf, two) && mmfile_is_binary(&mf)))
1830                                 abbrev = 40;
1831                 }
1832                 len += snprintf(msg + len, sizeof(msg) - len,
1833                                 "index %.*s..%.*s",
1834                                 abbrev, sha1_to_hex(one->sha1),
1835                                 abbrev, sha1_to_hex(two->sha1));
1836                 if (one->mode == two->mode)
1837                         len += snprintf(msg + len, sizeof(msg) - len,
1838                                         " %06o", one->mode);
1839                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
1840         }
1841
1842         if (len)
1843                 msg[--len] = 0;
1844         xfrm_msg = len ? msg : NULL;
1845
1846         if (!pgm &&
1847             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1848             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1849                 /* a filepair that changes between file and symlink
1850                  * needs to be split into deletion and creation.
1851                  */
1852                 struct diff_filespec *null = alloc_filespec(two->path);
1853                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1854                 free(null);
1855                 null = alloc_filespec(one->path);
1856                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1857                 free(null);
1858         }
1859         else
1860                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1861                              complete_rewrite);
1862
1863         free(name_munged);
1864         free(other_munged);
1865 }
1866
1867 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1868                          struct diffstat_t *diffstat)
1869 {
1870         const char *name;
1871         const char *other;
1872         int complete_rewrite = 0;
1873
1874         if (DIFF_PAIR_UNMERGED(p)) {
1875                 /* unmerged */
1876                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
1877                 return;
1878         }
1879
1880         name = p->one->path;
1881         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1882
1883         diff_fill_sha1_info(p->one);
1884         diff_fill_sha1_info(p->two);
1885
1886         if (p->status == DIFF_STATUS_MODIFIED && p->score)
1887                 complete_rewrite = 1;
1888         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
1889 }
1890
1891 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
1892 {
1893         const char *name;
1894         const char *other;
1895
1896         if (DIFF_PAIR_UNMERGED(p)) {
1897                 /* unmerged */
1898                 return;
1899         }
1900
1901         name = p->one->path;
1902         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1903
1904         diff_fill_sha1_info(p->one);
1905         diff_fill_sha1_info(p->two);
1906
1907         builtin_checkdiff(name, other, p->one, p->two, o);
1908 }
1909
1910 void diff_setup(struct diff_options *options)
1911 {
1912         memset(options, 0, sizeof(*options));
1913         options->line_termination = '\n';
1914         options->break_opt = -1;
1915         options->rename_limit = -1;
1916         options->context = 3;
1917         options->msg_sep = "";
1918
1919         options->change = diff_change;
1920         options->add_remove = diff_addremove;
1921         options->color_diff = diff_use_color_default;
1922         options->detect_rename = diff_detect_rename_default;
1923 }
1924
1925 int diff_setup_done(struct diff_options *options)
1926 {
1927         int count = 0;
1928
1929         if (options->output_format & DIFF_FORMAT_NAME)
1930                 count++;
1931         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
1932                 count++;
1933         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
1934                 count++;
1935         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
1936                 count++;
1937         if (count > 1)
1938                 die("--name-only, --name-status, --check and -s are mutually exclusive");
1939
1940         if (options->find_copies_harder)
1941                 options->detect_rename = DIFF_DETECT_COPY;
1942
1943         if (options->output_format & (DIFF_FORMAT_NAME |
1944                                       DIFF_FORMAT_NAME_STATUS |
1945                                       DIFF_FORMAT_CHECKDIFF |
1946                                       DIFF_FORMAT_NO_OUTPUT))
1947                 options->output_format &= ~(DIFF_FORMAT_RAW |
1948                                             DIFF_FORMAT_NUMSTAT |
1949                                             DIFF_FORMAT_DIFFSTAT |
1950                                             DIFF_FORMAT_SHORTSTAT |
1951                                             DIFF_FORMAT_SUMMARY |
1952                                             DIFF_FORMAT_PATCH);
1953
1954         /*
1955          * These cases always need recursive; we do not drop caller-supplied
1956          * recursive bits for other formats here.
1957          */
1958         if (options->output_format & (DIFF_FORMAT_PATCH |
1959                                       DIFF_FORMAT_NUMSTAT |
1960                                       DIFF_FORMAT_DIFFSTAT |
1961                                       DIFF_FORMAT_SHORTSTAT |
1962                                       DIFF_FORMAT_SUMMARY |
1963                                       DIFF_FORMAT_CHECKDIFF))
1964                 options->recursive = 1;
1965         /*
1966          * Also pickaxe would not work very well if you do not say recursive
1967          */
1968         if (options->pickaxe)
1969                 options->recursive = 1;
1970
1971         if (options->detect_rename && options->rename_limit < 0)
1972                 options->rename_limit = diff_rename_limit_default;
1973         if (options->setup & DIFF_SETUP_USE_CACHE) {
1974                 if (!active_cache)
1975                         /* read-cache does not die even when it fails
1976                          * so it is safe for us to do this here.  Also
1977                          * it does not smudge active_cache or active_nr
1978                          * when it fails, so we do not have to worry about
1979                          * cleaning it up ourselves either.
1980                          */
1981                         read_cache();
1982         }
1983         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1984                 use_size_cache = 1;
1985         if (options->abbrev <= 0 || 40 < options->abbrev)
1986                 options->abbrev = 40; /* full */
1987
1988         /*
1989          * It does not make sense to show the first hit we happened
1990          * to have found.  It does not make sense not to return with
1991          * exit code in such a case either.
1992          */
1993         if (options->quiet) {
1994                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
1995                 options->exit_with_status = 1;
1996         }
1997
1998         /*
1999          * If we postprocess in diffcore, we cannot simply return
2000          * upon the first hit.  We need to run diff as usual.
2001          */
2002         if (options->pickaxe || options->filter)
2003                 options->quiet = 0;
2004
2005         return 0;
2006 }
2007
2008 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2009 {
2010         char c, *eq;
2011         int len;
2012
2013         if (*arg != '-')
2014                 return 0;
2015         c = *++arg;
2016         if (!c)
2017                 return 0;
2018         if (c == arg_short) {
2019                 c = *++arg;
2020                 if (!c)
2021                         return 1;
2022                 if (val && isdigit(c)) {
2023                         char *end;
2024                         int n = strtoul(arg, &end, 10);
2025                         if (*end)
2026                                 return 0;
2027                         *val = n;
2028                         return 1;
2029                 }
2030                 return 0;
2031         }
2032         if (c != '-')
2033                 return 0;
2034         arg++;
2035         eq = strchr(arg, '=');
2036         if (eq)
2037                 len = eq - arg;
2038         else
2039                 len = strlen(arg);
2040         if (!len || strncmp(arg, arg_long, len))
2041                 return 0;
2042         if (eq) {
2043                 int n;
2044                 char *end;
2045                 if (!isdigit(*++eq))
2046                         return 0;
2047                 n = strtoul(eq, &end, 10);
2048                 if (*end)
2049                         return 0;
2050                 *val = n;
2051         }
2052         return 1;
2053 }
2054
2055 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2056 {
2057         const char *arg = av[0];
2058         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2059                 options->output_format |= DIFF_FORMAT_PATCH;
2060         else if (opt_arg(arg, 'U', "unified", &options->context))
2061                 options->output_format |= DIFF_FORMAT_PATCH;
2062         else if (!strcmp(arg, "--raw"))
2063                 options->output_format |= DIFF_FORMAT_RAW;
2064         else if (!strcmp(arg, "--patch-with-raw")) {
2065                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2066         }
2067         else if (!strcmp(arg, "--numstat")) {
2068                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2069         }
2070         else if (!strcmp(arg, "--shortstat")) {
2071                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2072         }
2073         else if (!prefixcmp(arg, "--stat")) {
2074                 char *end;
2075                 int width = options->stat_width;
2076                 int name_width = options->stat_name_width;
2077                 arg += 6;
2078                 end = (char *)arg;
2079
2080                 switch (*arg) {
2081                 case '-':
2082                         if (!prefixcmp(arg, "-width="))
2083                                 width = strtoul(arg + 7, &end, 10);
2084                         else if (!prefixcmp(arg, "-name-width="))
2085                                 name_width = strtoul(arg + 12, &end, 10);
2086                         break;
2087                 case '=':
2088                         width = strtoul(arg+1, &end, 10);
2089                         if (*end == ',')
2090                                 name_width = strtoul(end+1, &end, 10);
2091                 }
2092
2093                 /* Important! This checks all the error cases! */
2094                 if (*end)
2095                         return 0;
2096                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2097                 options->stat_name_width = name_width;
2098                 options->stat_width = width;
2099         }
2100         else if (!strcmp(arg, "--check"))
2101                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2102         else if (!strcmp(arg, "--summary"))
2103                 options->output_format |= DIFF_FORMAT_SUMMARY;
2104         else if (!strcmp(arg, "--patch-with-stat")) {
2105                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2106         }
2107         else if (!strcmp(arg, "-z"))
2108                 options->line_termination = 0;
2109         else if (!prefixcmp(arg, "-l"))
2110                 options->rename_limit = strtoul(arg+2, NULL, 10);
2111         else if (!strcmp(arg, "--full-index"))
2112                 options->full_index = 1;
2113         else if (!strcmp(arg, "--binary")) {
2114                 options->output_format |= DIFF_FORMAT_PATCH;
2115                 options->binary = 1;
2116         }
2117         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
2118                 options->text = 1;
2119         }
2120         else if (!strcmp(arg, "--name-only"))
2121                 options->output_format |= DIFF_FORMAT_NAME;
2122         else if (!strcmp(arg, "--name-status"))
2123                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2124         else if (!strcmp(arg, "-R"))
2125                 options->reverse_diff = 1;
2126         else if (!prefixcmp(arg, "-S"))
2127                 options->pickaxe = arg + 2;
2128         else if (!strcmp(arg, "-s")) {
2129                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2130         }
2131         else if (!prefixcmp(arg, "-O"))
2132                 options->orderfile = arg + 2;
2133         else if (!prefixcmp(arg, "--diff-filter="))
2134                 options->filter = arg + 14;
2135         else if (!strcmp(arg, "--pickaxe-all"))
2136                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2137         else if (!strcmp(arg, "--pickaxe-regex"))
2138                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2139         else if (!prefixcmp(arg, "-B")) {
2140                 if ((options->break_opt =
2141                      diff_scoreopt_parse(arg)) == -1)
2142                         return -1;
2143         }
2144         else if (!prefixcmp(arg, "-M")) {
2145                 if ((options->rename_score =
2146                      diff_scoreopt_parse(arg)) == -1)
2147                         return -1;
2148                 options->detect_rename = DIFF_DETECT_RENAME;
2149         }
2150         else if (!prefixcmp(arg, "-C")) {
2151                 if ((options->rename_score =
2152                      diff_scoreopt_parse(arg)) == -1)
2153                         return -1;
2154                 options->detect_rename = DIFF_DETECT_COPY;
2155         }
2156         else if (!strcmp(arg, "--find-copies-harder"))
2157                 options->find_copies_harder = 1;
2158         else if (!strcmp(arg, "--abbrev"))
2159                 options->abbrev = DEFAULT_ABBREV;
2160         else if (!prefixcmp(arg, "--abbrev=")) {
2161                 options->abbrev = strtoul(arg + 9, NULL, 10);
2162                 if (options->abbrev < MINIMUM_ABBREV)
2163                         options->abbrev = MINIMUM_ABBREV;
2164                 else if (40 < options->abbrev)
2165                         options->abbrev = 40;
2166         }
2167         else if (!strcmp(arg, "--color"))
2168                 options->color_diff = 1;
2169         else if (!strcmp(arg, "--no-color"))
2170                 options->color_diff = 0;
2171         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2172                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2173         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2174                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2175         else if (!strcmp(arg, "--ignore-space-at-eol"))
2176                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2177         else if (!strcmp(arg, "--color-words"))
2178                 options->color_diff = options->color_diff_words = 1;
2179         else if (!strcmp(arg, "--no-renames"))
2180                 options->detect_rename = 0;
2181         else if (!strcmp(arg, "--exit-code"))
2182                 options->exit_with_status = 1;
2183         else if (!strcmp(arg, "--quiet"))
2184                 options->quiet = 1;
2185         else
2186                 return 0;
2187         return 1;
2188 }
2189
2190 static int parse_num(const char **cp_p)
2191 {
2192         unsigned long num, scale;
2193         int ch, dot;
2194         const char *cp = *cp_p;
2195
2196         num = 0;
2197         scale = 1;
2198         dot = 0;
2199         for(;;) {
2200                 ch = *cp;
2201                 if ( !dot && ch == '.' ) {
2202                         scale = 1;
2203                         dot = 1;
2204                 } else if ( ch == '%' ) {
2205                         scale = dot ? scale*100 : 100;
2206                         cp++;   /* % is always at the end */
2207                         break;
2208                 } else if ( ch >= '0' && ch <= '9' ) {
2209                         if ( scale < 100000 ) {
2210                                 scale *= 10;
2211                                 num = (num*10) + (ch-'0');
2212                         }
2213                 } else {
2214                         break;
2215                 }
2216                 cp++;
2217         }
2218         *cp_p = cp;
2219
2220         /* user says num divided by scale and we say internally that
2221          * is MAX_SCORE * num / scale.
2222          */
2223         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2224 }
2225
2226 int diff_scoreopt_parse(const char *opt)
2227 {
2228         int opt1, opt2, cmd;
2229
2230         if (*opt++ != '-')
2231                 return -1;
2232         cmd = *opt++;
2233         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2234                 return -1; /* that is not a -M, -C nor -B option */
2235
2236         opt1 = parse_num(&opt);
2237         if (cmd != 'B')
2238                 opt2 = 0;
2239         else {
2240                 if (*opt == 0)
2241                         opt2 = 0;
2242                 else if (*opt != '/')
2243                         return -1; /* we expect -B80/99 or -B80 */
2244                 else {
2245                         opt++;
2246                         opt2 = parse_num(&opt);
2247                 }
2248         }
2249         if (*opt != 0)
2250                 return -1;
2251         return opt1 | (opt2 << 16);
2252 }
2253
2254 struct diff_queue_struct diff_queued_diff;
2255
2256 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2257 {
2258         if (queue->alloc <= queue->nr) {
2259                 queue->alloc = alloc_nr(queue->alloc);
2260                 queue->queue = xrealloc(queue->queue,
2261                                         sizeof(dp) * queue->alloc);
2262         }
2263         queue->queue[queue->nr++] = dp;
2264 }
2265
2266 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2267                                  struct diff_filespec *one,
2268                                  struct diff_filespec *two)
2269 {
2270         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2271         dp->one = one;
2272         dp->two = two;
2273         if (queue)
2274                 diff_q(queue, dp);
2275         return dp;
2276 }
2277
2278 void diff_free_filepair(struct diff_filepair *p)
2279 {
2280         diff_free_filespec_data(p->one);
2281         diff_free_filespec_data(p->two);
2282         free(p->one);
2283         free(p->two);
2284         free(p);
2285 }
2286
2287 /* This is different from find_unique_abbrev() in that
2288  * it stuffs the result with dots for alignment.
2289  */
2290 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2291 {
2292         int abblen;
2293         const char *abbrev;
2294         if (len == 40)
2295                 return sha1_to_hex(sha1);
2296
2297         abbrev = find_unique_abbrev(sha1, len);
2298         if (!abbrev)
2299                 return sha1_to_hex(sha1);
2300         abblen = strlen(abbrev);
2301         if (abblen < 37) {
2302                 static char hex[41];
2303                 if (len < abblen && abblen <= len + 2)
2304                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2305                 else
2306                         sprintf(hex, "%s...", abbrev);
2307                 return hex;
2308         }
2309         return sha1_to_hex(sha1);
2310 }
2311
2312 static void diff_flush_raw(struct diff_filepair *p,
2313                            struct diff_options *options)
2314 {
2315         int two_paths;
2316         char status[10];
2317         int abbrev = options->abbrev;
2318         const char *path_one, *path_two;
2319         int inter_name_termination = '\t';
2320         int line_termination = options->line_termination;
2321
2322         if (!line_termination)
2323                 inter_name_termination = 0;
2324
2325         path_one = p->one->path;
2326         path_two = p->two->path;
2327         if (line_termination) {
2328                 path_one = quote_one(path_one);
2329                 path_two = quote_one(path_two);
2330         }
2331
2332         if (p->score)
2333                 sprintf(status, "%c%03d", p->status,
2334                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
2335         else {
2336                 status[0] = p->status;
2337                 status[1] = 0;
2338         }
2339         switch (p->status) {
2340         case DIFF_STATUS_COPIED:
2341         case DIFF_STATUS_RENAMED:
2342                 two_paths = 1;
2343                 break;
2344         case DIFF_STATUS_ADDED:
2345         case DIFF_STATUS_DELETED:
2346                 two_paths = 0;
2347                 break;
2348         default:
2349                 two_paths = 0;
2350                 break;
2351         }
2352         if (!(options->output_format & DIFF_FORMAT_NAME_STATUS)) {
2353                 printf(":%06o %06o %s ",
2354                        p->one->mode, p->two->mode,
2355                        diff_unique_abbrev(p->one->sha1, abbrev));
2356                 printf("%s ",
2357                        diff_unique_abbrev(p->two->sha1, abbrev));
2358         }
2359         printf("%s%c%s", status, inter_name_termination, path_one);
2360         if (two_paths)
2361                 printf("%c%s", inter_name_termination, path_two);
2362         putchar(line_termination);
2363         if (path_one != p->one->path)
2364                 free((void*)path_one);
2365         if (path_two != p->two->path)
2366                 free((void*)path_two);
2367 }
2368
2369 static void diff_flush_name(struct diff_filepair *p, struct diff_options *opt)
2370 {
2371         char *path = p->two->path;
2372
2373         if (opt->line_termination)
2374                 path = quote_one(p->two->path);
2375         printf("%s%c", path, opt->line_termination);
2376         if (p->two->path != path)
2377                 free(path);
2378 }
2379
2380 int diff_unmodified_pair(struct diff_filepair *p)
2381 {
2382         /* This function is written stricter than necessary to support
2383          * the currently implemented transformers, but the idea is to
2384          * let transformers to produce diff_filepairs any way they want,
2385          * and filter and clean them up here before producing the output.
2386          */
2387         struct diff_filespec *one, *two;
2388
2389         if (DIFF_PAIR_UNMERGED(p))
2390                 return 0; /* unmerged is interesting */
2391
2392         one = p->one;
2393         two = p->two;
2394
2395         /* deletion, addition, mode or type change
2396          * and rename are all interesting.
2397          */
2398         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2399             DIFF_PAIR_MODE_CHANGED(p) ||
2400             strcmp(one->path, two->path))
2401                 return 0;
2402
2403         /* both are valid and point at the same path.  that is, we are
2404          * dealing with a change.
2405          */
2406         if (one->sha1_valid && two->sha1_valid &&
2407             !hashcmp(one->sha1, two->sha1))
2408                 return 1; /* no change */
2409         if (!one->sha1_valid && !two->sha1_valid)
2410                 return 1; /* both look at the same file on the filesystem. */
2411         return 0;
2412 }
2413
2414 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2415 {
2416         if (diff_unmodified_pair(p))
2417                 return;
2418
2419         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2420             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2421                 return; /* no tree diffs in patch format */
2422
2423         run_diff(p, o);
2424 }
2425
2426 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2427                             struct diffstat_t *diffstat)
2428 {
2429         if (diff_unmodified_pair(p))
2430                 return;
2431
2432         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2433             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2434                 return; /* no tree diffs in patch format */
2435
2436         run_diffstat(p, o, diffstat);
2437 }
2438
2439 static void diff_flush_checkdiff(struct diff_filepair *p,
2440                 struct diff_options *o)
2441 {
2442         if (diff_unmodified_pair(p))
2443                 return;
2444
2445         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2446             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2447                 return; /* no tree diffs in patch format */
2448
2449         run_checkdiff(p, o);
2450 }
2451
2452 int diff_queue_is_empty(void)
2453 {
2454         struct diff_queue_struct *q = &diff_queued_diff;
2455         int i;
2456         for (i = 0; i < q->nr; i++)
2457                 if (!diff_unmodified_pair(q->queue[i]))
2458                         return 0;
2459         return 1;
2460 }
2461
2462 #if DIFF_DEBUG
2463 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2464 {
2465         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2466                 x, one ? one : "",
2467                 s->path,
2468                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2469                 s->mode,
2470                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2471         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2472                 x, one ? one : "",
2473                 s->size, s->xfrm_flags);
2474 }
2475
2476 void diff_debug_filepair(const struct diff_filepair *p, int i)
2477 {
2478         diff_debug_filespec(p->one, i, "one");
2479         diff_debug_filespec(p->two, i, "two");
2480         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
2481                 p->score, p->status ? p->status : '?',
2482                 p->source_stays, p->broken_pair);
2483 }
2484
2485 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2486 {
2487         int i;
2488         if (msg)
2489                 fprintf(stderr, "%s\n", msg);
2490         fprintf(stderr, "q->nr = %d\n", q->nr);
2491         for (i = 0; i < q->nr; i++) {
2492                 struct diff_filepair *p = q->queue[i];
2493                 diff_debug_filepair(p, i);
2494         }
2495 }
2496 #endif
2497
2498 static void diff_resolve_rename_copy(void)
2499 {
2500         int i, j;
2501         struct diff_filepair *p, *pp;
2502         struct diff_queue_struct *q = &diff_queued_diff;
2503
2504         diff_debug_queue("resolve-rename-copy", q);
2505
2506         for (i = 0; i < q->nr; i++) {
2507                 p = q->queue[i];
2508                 p->status = 0; /* undecided */
2509                 if (DIFF_PAIR_UNMERGED(p))
2510                         p->status = DIFF_STATUS_UNMERGED;
2511                 else if (!DIFF_FILE_VALID(p->one))
2512                         p->status = DIFF_STATUS_ADDED;
2513                 else if (!DIFF_FILE_VALID(p->two))
2514                         p->status = DIFF_STATUS_DELETED;
2515                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2516                         p->status = DIFF_STATUS_TYPE_CHANGED;
2517
2518                 /* from this point on, we are dealing with a pair
2519                  * whose both sides are valid and of the same type, i.e.
2520                  * either in-place edit or rename/copy edit.
2521                  */
2522                 else if (DIFF_PAIR_RENAME(p)) {
2523                         if (p->source_stays) {
2524                                 p->status = DIFF_STATUS_COPIED;
2525                                 continue;
2526                         }
2527                         /* See if there is some other filepair that
2528                          * copies from the same source as us.  If so
2529                          * we are a copy.  Otherwise we are either a
2530                          * copy if the path stays, or a rename if it
2531                          * does not, but we already handled "stays" case.
2532                          */
2533                         for (j = i + 1; j < q->nr; j++) {
2534                                 pp = q->queue[j];
2535                                 if (strcmp(pp->one->path, p->one->path))
2536                                         continue; /* not us */
2537                                 if (!DIFF_PAIR_RENAME(pp))
2538                                         continue; /* not a rename/copy */
2539                                 /* pp is a rename/copy from the same source */
2540                                 p->status = DIFF_STATUS_COPIED;
2541                                 break;
2542                         }
2543                         if (!p->status)
2544                                 p->status = DIFF_STATUS_RENAMED;
2545                 }
2546                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2547                          p->one->mode != p->two->mode ||
2548                          is_null_sha1(p->one->sha1))
2549                         p->status = DIFF_STATUS_MODIFIED;
2550                 else {
2551                         /* This is a "no-change" entry and should not
2552                          * happen anymore, but prepare for broken callers.
2553                          */
2554                         error("feeding unmodified %s to diffcore",
2555                               p->one->path);
2556                         p->status = DIFF_STATUS_UNKNOWN;
2557                 }
2558         }
2559         diff_debug_queue("resolve-rename-copy done", q);
2560 }
2561
2562 static int check_pair_status(struct diff_filepair *p)
2563 {
2564         switch (p->status) {
2565         case DIFF_STATUS_UNKNOWN:
2566                 return 0;
2567         case 0:
2568                 die("internal error in diff-resolve-rename-copy");
2569         default:
2570                 return 1;
2571         }
2572 }
2573
2574 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2575 {
2576         int fmt = opt->output_format;
2577
2578         if (fmt & DIFF_FORMAT_CHECKDIFF)
2579                 diff_flush_checkdiff(p, opt);
2580         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2581                 diff_flush_raw(p, opt);
2582         else if (fmt & DIFF_FORMAT_NAME)
2583                 diff_flush_name(p, opt);
2584 }
2585
2586 static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
2587 {
2588         char *name = quote_one(fs->path);
2589         if (fs->mode)
2590                 printf(" %s mode %06o %s\n", newdelete, fs->mode, name);
2591         else
2592                 printf(" %s %s\n", newdelete, name);
2593         free(name);
2594 }
2595
2596
2597 static void show_mode_change(struct diff_filepair *p, int show_name)
2598 {
2599         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2600                 if (show_name) {
2601                         char *name = quote_one(p->two->path);
2602                         printf(" mode change %06o => %06o %s\n",
2603                                p->one->mode, p->two->mode, name);
2604                         free(name);
2605                 }
2606                 else
2607                         printf(" mode change %06o => %06o\n",
2608                                p->one->mode, p->two->mode);
2609         }
2610 }
2611
2612 static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
2613 {
2614         char *names = pprint_rename(p->one->path, p->two->path);
2615
2616         printf(" %s %s (%d%%)\n", renamecopy, names,
2617                (int)(0.5 + p->score * 100.0/MAX_SCORE));
2618         free(names);
2619         show_mode_change(p, 0);
2620 }
2621
2622 static void diff_summary(struct diff_filepair *p)
2623 {
2624         switch(p->status) {
2625         case DIFF_STATUS_DELETED:
2626                 show_file_mode_name("delete", p->one);
2627                 break;
2628         case DIFF_STATUS_ADDED:
2629                 show_file_mode_name("create", p->two);
2630                 break;
2631         case DIFF_STATUS_COPIED:
2632                 show_rename_copy("copy", p);
2633                 break;
2634         case DIFF_STATUS_RENAMED:
2635                 show_rename_copy("rename", p);
2636                 break;
2637         default:
2638                 if (p->score) {
2639                         char *name = quote_one(p->two->path);
2640                         printf(" rewrite %s (%d%%)\n", name,
2641                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
2642                         free(name);
2643                         show_mode_change(p, 0);
2644                 } else  show_mode_change(p, 1);
2645                 break;
2646         }
2647 }
2648
2649 struct patch_id_t {
2650         struct xdiff_emit_state xm;
2651         SHA_CTX *ctx;
2652         int patchlen;
2653 };
2654
2655 static int remove_space(char *line, int len)
2656 {
2657         int i;
2658         char *dst = line;
2659         unsigned char c;
2660
2661         for (i = 0; i < len; i++)
2662                 if (!isspace((c = line[i])))
2663                         *dst++ = c;
2664
2665         return dst - line;
2666 }
2667
2668 static void patch_id_consume(void *priv, char *line, unsigned long len)
2669 {
2670         struct patch_id_t *data = priv;
2671         int new_len;
2672
2673         /* Ignore line numbers when computing the SHA1 of the patch */
2674         if (!prefixcmp(line, "@@ -"))
2675                 return;
2676
2677         new_len = remove_space(line, len);
2678
2679         SHA1_Update(data->ctx, line, new_len);
2680         data->patchlen += new_len;
2681 }
2682
2683 /* returns 0 upon success, and writes result into sha1 */
2684 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2685 {
2686         struct diff_queue_struct *q = &diff_queued_diff;
2687         int i;
2688         SHA_CTX ctx;
2689         struct patch_id_t data;
2690         char buffer[PATH_MAX * 4 + 20];
2691
2692         SHA1_Init(&ctx);
2693         memset(&data, 0, sizeof(struct patch_id_t));
2694         data.ctx = &ctx;
2695         data.xm.consume = patch_id_consume;
2696
2697         for (i = 0; i < q->nr; i++) {
2698                 xpparam_t xpp;
2699                 xdemitconf_t xecfg;
2700                 xdemitcb_t ecb;
2701                 mmfile_t mf1, mf2;
2702                 struct diff_filepair *p = q->queue[i];
2703                 int len1, len2;
2704
2705                 if (p->status == 0)
2706                         return error("internal diff status error");
2707                 if (p->status == DIFF_STATUS_UNKNOWN)
2708                         continue;
2709                 if (diff_unmodified_pair(p))
2710                         continue;
2711                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2712                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2713                         continue;
2714                 if (DIFF_PAIR_UNMERGED(p))
2715                         continue;
2716
2717                 diff_fill_sha1_info(p->one);
2718                 diff_fill_sha1_info(p->two);
2719                 if (fill_mmfile(&mf1, p->one) < 0 ||
2720                                 fill_mmfile(&mf2, p->two) < 0)
2721                         return error("unable to read files to diff");
2722
2723                 /* Maybe hash p->two? into the patch id? */
2724                 if (mmfile_is_binary(&mf2))
2725                         continue;
2726
2727                 len1 = remove_space(p->one->path, strlen(p->one->path));
2728                 len2 = remove_space(p->two->path, strlen(p->two->path));
2729                 if (p->one->mode == 0)
2730                         len1 = snprintf(buffer, sizeof(buffer),
2731                                         "diff--gita/%.*sb/%.*s"
2732                                         "newfilemode%06o"
2733                                         "---/dev/null"
2734                                         "+++b/%.*s",
2735                                         len1, p->one->path,
2736                                         len2, p->two->path,
2737                                         p->two->mode,
2738                                         len2, p->two->path);
2739                 else if (p->two->mode == 0)
2740                         len1 = snprintf(buffer, sizeof(buffer),
2741                                         "diff--gita/%.*sb/%.*s"
2742                                         "deletedfilemode%06o"
2743                                         "---a/%.*s"
2744                                         "+++/dev/null",
2745                                         len1, p->one->path,
2746                                         len2, p->two->path,
2747                                         p->one->mode,
2748                                         len1, p->one->path);
2749                 else
2750                         len1 = snprintf(buffer, sizeof(buffer),
2751                                         "diff--gita/%.*sb/%.*s"
2752                                         "---a/%.*s"
2753                                         "+++b/%.*s",
2754                                         len1, p->one->path,
2755                                         len2, p->two->path,
2756                                         len1, p->one->path,
2757                                         len2, p->two->path);
2758                 SHA1_Update(&ctx, buffer, len1);
2759
2760                 xpp.flags = XDF_NEED_MINIMAL;
2761                 xecfg.ctxlen = 3;
2762                 xecfg.flags = XDL_EMIT_FUNCNAMES;
2763                 ecb.outf = xdiff_outf;
2764                 ecb.priv = &data;
2765                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
2766         }
2767
2768         SHA1_Final(sha1, &ctx);
2769         return 0;
2770 }
2771
2772 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
2773 {
2774         struct diff_queue_struct *q = &diff_queued_diff;
2775         int i;
2776         int result = diff_get_patch_id(options, sha1);
2777
2778         for (i = 0; i < q->nr; i++)
2779                 diff_free_filepair(q->queue[i]);
2780
2781         free(q->queue);
2782         q->queue = NULL;
2783         q->nr = q->alloc = 0;
2784
2785         return result;
2786 }
2787
2788 static int is_summary_empty(const struct diff_queue_struct *q)
2789 {
2790         int i;
2791
2792         for (i = 0; i < q->nr; i++) {
2793                 const struct diff_filepair *p = q->queue[i];
2794
2795                 switch (p->status) {
2796                 case DIFF_STATUS_DELETED:
2797                 case DIFF_STATUS_ADDED:
2798                 case DIFF_STATUS_COPIED:
2799                 case DIFF_STATUS_RENAMED:
2800                         return 0;
2801                 default:
2802                         if (p->score)
2803                                 return 0;
2804                         if (p->one->mode && p->two->mode &&
2805                             p->one->mode != p->two->mode)
2806                                 return 0;
2807                         break;
2808                 }
2809         }
2810         return 1;
2811 }
2812
2813 void diff_flush(struct diff_options *options)
2814 {
2815         struct diff_queue_struct *q = &diff_queued_diff;
2816         int i, output_format = options->output_format;
2817         int separator = 0;
2818
2819         /*
2820          * Order: raw, stat, summary, patch
2821          * or:    name/name-status/checkdiff (other bits clear)
2822          */
2823         if (!q->nr)
2824                 goto free_queue;
2825
2826         if (output_format & (DIFF_FORMAT_RAW |
2827                              DIFF_FORMAT_NAME |
2828                              DIFF_FORMAT_NAME_STATUS |
2829                              DIFF_FORMAT_CHECKDIFF)) {
2830                 for (i = 0; i < q->nr; i++) {
2831                         struct diff_filepair *p = q->queue[i];
2832                         if (check_pair_status(p))
2833                                 flush_one_pair(p, options);
2834                 }
2835                 separator++;
2836         }
2837
2838         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
2839                 struct diffstat_t diffstat;
2840
2841                 memset(&diffstat, 0, sizeof(struct diffstat_t));
2842                 diffstat.xm.consume = diffstat_consume;
2843                 for (i = 0; i < q->nr; i++) {
2844                         struct diff_filepair *p = q->queue[i];
2845                         if (check_pair_status(p))
2846                                 diff_flush_stat(p, options, &diffstat);
2847                 }
2848                 if (output_format & DIFF_FORMAT_NUMSTAT)
2849                         show_numstat(&diffstat, options);
2850                 if (output_format & DIFF_FORMAT_DIFFSTAT)
2851                         show_stats(&diffstat, options);
2852                 else if (output_format & DIFF_FORMAT_SHORTSTAT)
2853                         show_shortstats(&diffstat);
2854                 separator++;
2855         }
2856
2857         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
2858                 for (i = 0; i < q->nr; i++)
2859                         diff_summary(q->queue[i]);
2860                 separator++;
2861         }
2862
2863         if (output_format & DIFF_FORMAT_PATCH) {
2864                 if (separator) {
2865                         if (options->stat_sep) {
2866                                 /* attach patch instead of inline */
2867                                 fputs(options->stat_sep, stdout);
2868                         } else {
2869                                 putchar(options->line_termination);
2870                         }
2871                 }
2872
2873                 for (i = 0; i < q->nr; i++) {
2874                         struct diff_filepair *p = q->queue[i];
2875                         if (check_pair_status(p))
2876                                 diff_flush_patch(p, options);
2877                 }
2878         }
2879
2880         if (output_format & DIFF_FORMAT_CALLBACK)
2881                 options->format_callback(q, options, options->format_callback_data);
2882
2883         for (i = 0; i < q->nr; i++)
2884                 diff_free_filepair(q->queue[i]);
2885 free_queue:
2886         free(q->queue);
2887         q->queue = NULL;
2888         q->nr = q->alloc = 0;
2889 }
2890
2891 static void diffcore_apply_filter(const char *filter)
2892 {
2893         int i;
2894         struct diff_queue_struct *q = &diff_queued_diff;
2895         struct diff_queue_struct outq;
2896         outq.queue = NULL;
2897         outq.nr = outq.alloc = 0;
2898
2899         if (!filter)
2900                 return;
2901
2902         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
2903                 int found;
2904                 for (i = found = 0; !found && i < q->nr; i++) {
2905                         struct diff_filepair *p = q->queue[i];
2906                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2907                              ((p->score &&
2908                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2909                               (!p->score &&
2910                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2911                             ((p->status != DIFF_STATUS_MODIFIED) &&
2912                              strchr(filter, p->status)))
2913                                 found++;
2914                 }
2915                 if (found)
2916                         return;
2917
2918                 /* otherwise we will clear the whole queue
2919                  * by copying the empty outq at the end of this
2920                  * function, but first clear the current entries
2921                  * in the queue.
2922                  */
2923                 for (i = 0; i < q->nr; i++)
2924                         diff_free_filepair(q->queue[i]);
2925         }
2926         else {
2927                 /* Only the matching ones */
2928                 for (i = 0; i < q->nr; i++) {
2929                         struct diff_filepair *p = q->queue[i];
2930
2931                         if (((p->status == DIFF_STATUS_MODIFIED) &&
2932                              ((p->score &&
2933                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
2934                               (!p->score &&
2935                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
2936                             ((p->status != DIFF_STATUS_MODIFIED) &&
2937                              strchr(filter, p->status)))
2938                                 diff_q(&outq, p);
2939                         else
2940                                 diff_free_filepair(p);
2941                 }
2942         }
2943         free(q->queue);
2944         *q = outq;
2945 }
2946
2947 void diffcore_std(struct diff_options *options)
2948 {
2949         if (options->quiet)
2950                 return;
2951         if (options->break_opt != -1)
2952                 diffcore_break(options->break_opt);
2953         if (options->detect_rename)
2954                 diffcore_rename(options);
2955         if (options->break_opt != -1)
2956                 diffcore_merge_broken();
2957         if (options->pickaxe)
2958                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
2959         if (options->orderfile)
2960                 diffcore_order(options->orderfile);
2961         diff_resolve_rename_copy();
2962         diffcore_apply_filter(options->filter);
2963
2964         options->has_changes = !!diff_queued_diff.nr;
2965 }
2966
2967
2968 void diff_addremove(struct diff_options *options,
2969                     int addremove, unsigned mode,
2970                     const unsigned char *sha1,
2971                     const char *base, const char *path)
2972 {
2973         char concatpath[PATH_MAX];
2974         struct diff_filespec *one, *two;
2975
2976         /* This may look odd, but it is a preparation for
2977          * feeding "there are unchanged files which should
2978          * not produce diffs, but when you are doing copy
2979          * detection you would need them, so here they are"
2980          * entries to the diff-core.  They will be prefixed
2981          * with something like '=' or '*' (I haven't decided
2982          * which but should not make any difference).
2983          * Feeding the same new and old to diff_change() 
2984          * also has the same effect.
2985          * Before the final output happens, they are pruned after
2986          * merged into rename/copy pairs as appropriate.
2987          */
2988         if (options->reverse_diff)
2989                 addremove = (addremove == '+' ? '-' :
2990                              addremove == '-' ? '+' : addremove);
2991
2992         if (!path) path = "";
2993         sprintf(concatpath, "%s%s", base, path);
2994         one = alloc_filespec(concatpath);
2995         two = alloc_filespec(concatpath);
2996
2997         if (addremove != '+')
2998                 fill_filespec(one, sha1, mode);
2999         if (addremove != '-')
3000                 fill_filespec(two, sha1, mode);
3001
3002         diff_queue(&diff_queued_diff, one, two);
3003         options->has_changes = 1;
3004 }
3005
3006 void diff_change(struct diff_options *options,
3007                  unsigned old_mode, unsigned new_mode,
3008                  const unsigned char *old_sha1,
3009                  const unsigned char *new_sha1,
3010                  const char *base, const char *path) 
3011 {
3012         char concatpath[PATH_MAX];
3013         struct diff_filespec *one, *two;
3014
3015         if (options->reverse_diff) {
3016                 unsigned tmp;
3017                 const unsigned char *tmp_c;
3018                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3019                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3020         }
3021         if (!path) path = "";
3022         sprintf(concatpath, "%s%s", base, path);
3023         one = alloc_filespec(concatpath);
3024         two = alloc_filespec(concatpath);
3025         fill_filespec(one, old_sha1, old_mode);
3026         fill_filespec(two, new_sha1, new_mode);
3027
3028         diff_queue(&diff_queued_diff, one, two);
3029         options->has_changes = 1;
3030 }
3031
3032 void diff_unmerge(struct diff_options *options,
3033                   const char *path,
3034                   unsigned mode, const unsigned char *sha1)
3035 {
3036         struct diff_filespec *one, *two;
3037         one = alloc_filespec(path);
3038         two = alloc_filespec(path);
3039         fill_filespec(one, sha1, mode);
3040         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3041 }