GIT v1.5.1.4
[git] / combine-diff.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "blob.h"
4 #include "diff.h"
5 #include "diffcore.h"
6 #include "quote.h"
7 #include "xdiff-interface.h"
8 #include "log-tree.h"
9
10 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
11 {
12         struct diff_queue_struct *q = &diff_queued_diff;
13         struct combine_diff_path *p;
14         int i;
15
16         if (!n) {
17                 struct combine_diff_path *list = NULL, **tail = &list;
18                 for (i = 0; i < q->nr; i++) {
19                         int len;
20                         const char *path;
21                         if (diff_unmodified_pair(q->queue[i]))
22                                 continue;
23                         path = q->queue[i]->two->path;
24                         len = strlen(path);
25                         p = xmalloc(combine_diff_path_size(num_parent, len));
26                         p->path = (char*) &(p->parent[num_parent]);
27                         memcpy(p->path, path, len);
28                         p->path[len] = 0;
29                         p->len = len;
30                         p->next = NULL;
31                         memset(p->parent, 0,
32                                sizeof(p->parent[0]) * num_parent);
33
34                         hashcpy(p->sha1, q->queue[i]->two->sha1);
35                         p->mode = q->queue[i]->two->mode;
36                         hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
37                         p->parent[n].mode = q->queue[i]->one->mode;
38                         p->parent[n].status = q->queue[i]->status;
39                         *tail = p;
40                         tail = &p->next;
41                 }
42                 return list;
43         }
44
45         for (p = curr; p; p = p->next) {
46                 int found = 0;
47                 if (!p->len)
48                         continue;
49                 for (i = 0; i < q->nr; i++) {
50                         const char *path;
51                         int len;
52
53                         if (diff_unmodified_pair(q->queue[i]))
54                                 continue;
55                         path = q->queue[i]->two->path;
56                         len = strlen(path);
57                         if (len == p->len && !memcmp(path, p->path, len)) {
58                                 found = 1;
59                                 hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
60                                 p->parent[n].mode = q->queue[i]->one->mode;
61                                 p->parent[n].status = q->queue[i]->status;
62                                 break;
63                         }
64                 }
65                 if (!found)
66                         p->len = 0;
67         }
68         return curr;
69 }
70
71 /* Lines lost from parent */
72 struct lline {
73         struct lline *next;
74         int len;
75         unsigned long parent_map;
76         char line[FLEX_ARRAY];
77 };
78
79 /* Lines surviving in the merge result */
80 struct sline {
81         struct lline *lost_head, **lost_tail;
82         char *bol;
83         int len;
84         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
85          * we did not change it).
86          * bit N is used for "interesting" lines, including context.
87          */
88         unsigned long flag;
89         unsigned long *p_lno;
90 };
91
92 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
93 {
94         char *blob;
95         enum object_type type;
96         if (is_null_sha1(sha1)) {
97                 /* deleted blob */
98                 *size = 0;
99                 return xcalloc(1, 1);
100         }
101         blob = read_sha1_file(sha1, &type, size);
102         if (type != OBJ_BLOB)
103                 die("object '%s' is not a blob!", sha1_to_hex(sha1));
104         return blob;
105 }
106
107 static void append_lost(struct sline *sline, int n, const char *line, int len)
108 {
109         struct lline *lline;
110         unsigned long this_mask = (1UL<<n);
111         if (line[len-1] == '\n')
112                 len--;
113
114         /* Check to see if we can squash things */
115         if (sline->lost_head) {
116                 struct lline *last_one = NULL;
117                 /* We cannot squash it with earlier one */
118                 for (lline = sline->lost_head;
119                      lline;
120                      lline = lline->next)
121                         if (lline->parent_map & this_mask)
122                                 last_one = lline;
123                 lline = last_one ? last_one->next : sline->lost_head;
124                 while (lline) {
125                         if (lline->len == len &&
126                             !memcmp(lline->line, line, len)) {
127                                 lline->parent_map |= this_mask;
128                                 return;
129                         }
130                         lline = lline->next;
131                 }
132         }
133
134         lline = xmalloc(sizeof(*lline) + len + 1);
135         lline->len = len;
136         lline->next = NULL;
137         lline->parent_map = this_mask;
138         memcpy(lline->line, line, len);
139         lline->line[len] = 0;
140         *sline->lost_tail = lline;
141         sline->lost_tail = &lline->next;
142 }
143
144 struct combine_diff_state {
145         struct xdiff_emit_state xm;
146
147         unsigned int lno;
148         int ob, on, nb, nn;
149         unsigned long nmask;
150         int num_parent;
151         int n;
152         struct sline *sline;
153         struct sline *lost_bucket;
154 };
155
156 static void consume_line(void *state_, char *line, unsigned long len)
157 {
158         struct combine_diff_state *state = state_;
159         if (5 < len && !memcmp("@@ -", line, 4)) {
160                 if (parse_hunk_header(line, len,
161                                       &state->ob, &state->on,
162                                       &state->nb, &state->nn))
163                         return;
164                 state->lno = state->nb;
165                 if (!state->nb)
166                         /* @@ -1,2 +0,0 @@ to remove the
167                          * first two lines...
168                          */
169                         state->nb = 1;
170                 if (state->nn == 0)
171                         /* @@ -X,Y +N,0 @@ removed Y lines
172                          * that would have come *after* line N
173                          * in the result.  Our lost buckets hang
174                          * to the line after the removed lines,
175                          */
176                         state->lost_bucket = &state->sline[state->nb];
177                 else
178                         state->lost_bucket = &state->sline[state->nb-1];
179                 if (!state->sline[state->nb-1].p_lno)
180                         state->sline[state->nb-1].p_lno =
181                                 xcalloc(state->num_parent,
182                                         sizeof(unsigned long));
183                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
184                 return;
185         }
186         if (!state->lost_bucket)
187                 return; /* not in any hunk yet */
188         switch (line[0]) {
189         case '-':
190                 append_lost(state->lost_bucket, state->n, line+1, len-1);
191                 break;
192         case '+':
193                 state->sline[state->lno-1].flag |= state->nmask;
194                 state->lno++;
195                 break;
196         }
197 }
198
199 static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
200                          struct sline *sline, unsigned int cnt, int n,
201                          int num_parent)
202 {
203         unsigned int p_lno, lno;
204         unsigned long nmask = (1UL << n);
205         xpparam_t xpp;
206         xdemitconf_t xecfg;
207         mmfile_t parent_file;
208         xdemitcb_t ecb;
209         struct combine_diff_state state;
210         unsigned long sz;
211
212         if (!cnt)
213                 return; /* result deleted */
214
215         parent_file.ptr = grab_blob(parent, &sz);
216         parent_file.size = sz;
217         xpp.flags = XDF_NEED_MINIMAL;
218         xecfg.ctxlen = 0;
219         xecfg.flags = 0;
220         ecb.outf = xdiff_outf;
221         ecb.priv = &state;
222         memset(&state, 0, sizeof(state));
223         state.xm.consume = consume_line;
224         state.nmask = nmask;
225         state.sline = sline;
226         state.lno = 1;
227         state.num_parent = num_parent;
228         state.n = n;
229
230         xdl_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
231         free(parent_file.ptr);
232
233         /* Assign line numbers for this parent.
234          *
235          * sline[lno].p_lno[n] records the first line number
236          * (counting from 1) for parent N if the final hunk display
237          * started by showing sline[lno] (possibly showing the lost
238          * lines attached to it first).
239          */
240         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
241                 struct lline *ll;
242                 sline[lno].p_lno[n] = p_lno;
243
244                 /* How many lines would this sline advance the p_lno? */
245                 ll = sline[lno].lost_head;
246                 while (ll) {
247                         if (ll->parent_map & nmask)
248                                 p_lno++; /* '-' means parent had it */
249                         ll = ll->next;
250                 }
251                 if (lno < cnt && !(sline[lno].flag & nmask))
252                         p_lno++; /* no '+' means parent had it */
253         }
254         sline[lno].p_lno[n] = p_lno; /* trailer */
255 }
256
257 static unsigned long context = 3;
258 static char combine_marker = '@';
259
260 static int interesting(struct sline *sline, unsigned long all_mask)
261 {
262         /* If some parents lost lines here, or if we have added to
263          * some parent, it is interesting.
264          */
265         return ((sline->flag & all_mask) || sline->lost_head);
266 }
267
268 static unsigned long adjust_hunk_tail(struct sline *sline,
269                                       unsigned long all_mask,
270                                       unsigned long hunk_begin,
271                                       unsigned long i)
272 {
273         /* i points at the first uninteresting line.  If the last line
274          * of the hunk was interesting only because it has some
275          * deletion, then it is not all that interesting for the
276          * purpose of giving trailing context lines.  This is because
277          * we output '-' line and then unmodified sline[i-1] itself in
278          * that case which gives us one extra context line.
279          */
280         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
281                 i--;
282         return i;
283 }
284
285 static unsigned long find_next(struct sline *sline,
286                                unsigned long mark,
287                                unsigned long i,
288                                unsigned long cnt,
289                                int look_for_uninteresting)
290 {
291         /* We have examined up to i-1 and are about to look at i.
292          * Find next interesting or uninteresting line.  Here,
293          * "interesting" does not mean interesting(), but marked by
294          * the give_context() function below (i.e. it includes context
295          * lines that are not interesting to interesting() function
296          * that are surrounded by interesting() ones.
297          */
298         while (i <= cnt)
299                 if (look_for_uninteresting
300                     ? !(sline[i].flag & mark)
301                     : (sline[i].flag & mark))
302                         return i;
303                 else
304                         i++;
305         return i;
306 }
307
308 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
309 {
310         unsigned long all_mask = (1UL<<num_parent) - 1;
311         unsigned long mark = (1UL<<num_parent);
312         unsigned long i;
313
314         /* Two groups of interesting lines may have a short gap of
315          * uninteresting lines.  Connect such groups to give them a
316          * bit of context.
317          *
318          * We first start from what the interesting() function says,
319          * and mark them with "mark", and paint context lines with the
320          * mark.  So interesting() would still say false for such context
321          * lines but they are treated as "interesting" in the end.
322          */
323         i = find_next(sline, mark, 0, cnt, 0);
324         if (cnt < i)
325                 return 0;
326
327         while (i <= cnt) {
328                 unsigned long j = (context < i) ? (i - context) : 0;
329                 unsigned long k;
330
331                 /* Paint a few lines before the first interesting line. */
332                 while (j < i)
333                         sline[j++].flag |= mark;
334
335         again:
336                 /* we know up to i is to be included.  where does the
337                  * next uninteresting one start?
338                  */
339                 j = find_next(sline, mark, i, cnt, 1);
340                 if (cnt < j)
341                         break; /* the rest are all interesting */
342
343                 /* lookahead context lines */
344                 k = find_next(sline, mark, j, cnt, 0);
345                 j = adjust_hunk_tail(sline, all_mask, i, j);
346
347                 if (k < j + context) {
348                         /* k is interesting and [j,k) are not, but
349                          * paint them interesting because the gap is small.
350                          */
351                         while (j < k)
352                                 sline[j++].flag |= mark;
353                         i = k;
354                         goto again;
355                 }
356
357                 /* j is the first uninteresting line and there is
358                  * no overlap beyond it within context lines.  Paint
359                  * the trailing edge a bit.
360                  */
361                 i = k;
362                 k = (j + context < cnt+1) ? j + context : cnt+1;
363                 while (j < k)
364                         sline[j++].flag |= mark;
365         }
366         return 1;
367 }
368
369 static int make_hunks(struct sline *sline, unsigned long cnt,
370                        int num_parent, int dense)
371 {
372         unsigned long all_mask = (1UL<<num_parent) - 1;
373         unsigned long mark = (1UL<<num_parent);
374         unsigned long i;
375         int has_interesting = 0;
376
377         for (i = 0; i <= cnt; i++) {
378                 if (interesting(&sline[i], all_mask))
379                         sline[i].flag |= mark;
380                 else
381                         sline[i].flag &= ~mark;
382         }
383         if (!dense)
384                 return give_context(sline, cnt, num_parent);
385
386         /* Look at each hunk, and if we have changes from only one
387          * parent, or the changes are the same from all but one
388          * parent, mark that uninteresting.
389          */
390         i = 0;
391         while (i <= cnt) {
392                 unsigned long j, hunk_begin, hunk_end;
393                 unsigned long same_diff;
394                 while (i <= cnt && !(sline[i].flag & mark))
395                         i++;
396                 if (cnt < i)
397                         break; /* No more interesting hunks */
398                 hunk_begin = i;
399                 for (j = i + 1; j <= cnt; j++) {
400                         if (!(sline[j].flag & mark)) {
401                                 /* Look beyond the end to see if there
402                                  * is an interesting line after this
403                                  * hunk within context span.
404                                  */
405                                 unsigned long la; /* lookahead */
406                                 int contin = 0;
407                                 la = adjust_hunk_tail(sline, all_mask,
408                                                      hunk_begin, j);
409                                 la = (la + context < cnt + 1) ?
410                                         (la + context) : cnt + 1;
411                                 while (j <= --la) {
412                                         if (sline[la].flag & mark) {
413                                                 contin = 1;
414                                                 break;
415                                         }
416                                 }
417                                 if (!contin)
418                                         break;
419                                 j = la;
420                         }
421                 }
422                 hunk_end = j;
423
424                 /* [i..hunk_end) are interesting.  Now is it really
425                  * interesting?  We check if there are only two versions
426                  * and the result matches one of them.  That is, we look
427                  * at:
428                  *   (+) line, which records lines added to which parents;
429                  *       this line appears in the result.
430                  *   (-) line, which records from what parents the line
431                  *       was removed; this line does not appear in the result.
432                  * then check the set of parents the result has difference
433                  * from, from all lines.  If there are lines that has
434                  * different set of parents that the result has differences
435                  * from, that means we have more than two versions.
436                  *
437                  * Even when we have only two versions, if the result does
438                  * not match any of the parents, the it should be considered
439                  * interesting.  In such a case, we would have all '+' line.
440                  * After passing the above "two versions" test, that would
441                  * appear as "the same set of parents" to be "all parents".
442                  */
443                 same_diff = 0;
444                 has_interesting = 0;
445                 for (j = i; j < hunk_end && !has_interesting; j++) {
446                         unsigned long this_diff = sline[j].flag & all_mask;
447                         struct lline *ll = sline[j].lost_head;
448                         if (this_diff) {
449                                 /* This has some changes.  Is it the
450                                  * same as others?
451                                  */
452                                 if (!same_diff)
453                                         same_diff = this_diff;
454                                 else if (same_diff != this_diff) {
455                                         has_interesting = 1;
456                                         break;
457                                 }
458                         }
459                         while (ll && !has_interesting) {
460                                 /* Lost this line from these parents;
461                                  * who are they?  Are they the same?
462                                  */
463                                 this_diff = ll->parent_map;
464                                 if (!same_diff)
465                                         same_diff = this_diff;
466                                 else if (same_diff != this_diff) {
467                                         has_interesting = 1;
468                                 }
469                                 ll = ll->next;
470                         }
471                 }
472
473                 if (!has_interesting && same_diff != all_mask) {
474                         /* This hunk is not that interesting after all */
475                         for (j = hunk_begin; j < hunk_end; j++)
476                                 sline[j].flag &= ~mark;
477                 }
478                 i = hunk_end;
479         }
480
481         has_interesting = give_context(sline, cnt, num_parent);
482         return has_interesting;
483 }
484
485 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
486 {
487         l0 = sline[l0].p_lno[n];
488         l1 = sline[l1].p_lno[n];
489         printf(" -%lu,%lu", l0, l1-l0-null_context);
490 }
491
492 static int hunk_comment_line(const char *bol)
493 {
494         int ch;
495
496         if (!bol)
497                 return 0;
498         ch = *bol & 0xff;
499         return (isalpha(ch) || ch == '_' || ch == '$');
500 }
501
502 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
503                        int use_color)
504 {
505         unsigned long mark = (1UL<<num_parent);
506         int i;
507         unsigned long lno = 0;
508         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
509         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
510         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
511         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
512         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
513
514         if (!cnt)
515                 return; /* result deleted */
516
517         while (1) {
518                 struct sline *sl = &sline[lno];
519                 unsigned long hunk_end;
520                 unsigned long rlines;
521                 const char *hunk_comment = NULL;
522                 unsigned long null_context = 0;
523
524                 while (lno <= cnt && !(sline[lno].flag & mark)) {
525                         if (hunk_comment_line(sline[lno].bol))
526                                 hunk_comment = sline[lno].bol;
527                         lno++;
528                 }
529                 if (cnt < lno)
530                         break;
531                 else {
532                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
533                                 if (!(sline[hunk_end].flag & mark))
534                                         break;
535                 }
536                 rlines = hunk_end - lno;
537                 if (cnt < hunk_end)
538                         rlines--; /* pointing at the last delete hunk */
539
540                 if (!context) {
541                         /*
542                          * Even when running with --unified=0, all
543                          * lines in the hunk needs to be processed in
544                          * the loop below in order to show the
545                          * deletion recorded in lost_head.  However,
546                          * we do not want to show the resulting line
547                          * with all blank context markers in such a
548                          * case.  Compensate.
549                          */
550                         unsigned long j;
551                         for (j = lno; j < hunk_end; j++)
552                                 if (!(sline[j].flag & (mark-1)))
553                                         null_context++;
554                         rlines -= null_context;
555                 }
556
557                 fputs(c_frag, stdout);
558                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
559                 for (i = 0; i < num_parent; i++)
560                         show_parent_lno(sline, lno, hunk_end, i, null_context);
561                 printf(" +%lu,%lu ", lno+1, rlines);
562                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
563
564                 if (hunk_comment) {
565                         int comment_end = 0;
566                         for (i = 0; i < 40; i++) {
567                                 int ch = hunk_comment[i] & 0xff;
568                                 if (!ch || ch == '\n')
569                                         break;
570                                 if (!isspace(ch))
571                                     comment_end = i;
572                         }
573                         if (comment_end)
574                                 putchar(' ');
575                         for (i = 0; i < comment_end; i++)
576                                 putchar(hunk_comment[i]);
577                 }
578
579                 printf("%s\n", c_reset);
580                 while (lno < hunk_end) {
581                         struct lline *ll;
582                         int j;
583                         unsigned long p_mask;
584                         sl = &sline[lno++];
585                         ll = sl->lost_head;
586                         while (ll) {
587                                 fputs(c_old, stdout);
588                                 for (j = 0; j < num_parent; j++) {
589                                         if (ll->parent_map & (1UL<<j))
590                                                 putchar('-');
591                                         else
592                                                 putchar(' ');
593                                 }
594                                 printf("%s%s\n", ll->line, c_reset);
595                                 ll = ll->next;
596                         }
597                         if (cnt < lno)
598                                 break;
599                         p_mask = 1;
600                         if (!(sl->flag & (mark-1))) {
601                                 /*
602                                  * This sline was here to hang the
603                                  * lost lines in front of it.
604                                  */
605                                 if (!context)
606                                         continue;
607                                 fputs(c_plain, stdout);
608                         }
609                         else
610                                 fputs(c_new, stdout);
611                         for (j = 0; j < num_parent; j++) {
612                                 if (p_mask & sl->flag)
613                                         putchar('+');
614                                 else
615                                         putchar(' ');
616                                 p_mask <<= 1;
617                         }
618                         printf("%.*s%s\n", sl->len, sl->bol, c_reset);
619                 }
620         }
621 }
622
623 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
624                                int i, int j)
625 {
626         /* We have already examined parent j and we know parent i
627          * and parent j are the same, so reuse the combined result
628          * of parent j for parent i.
629          */
630         unsigned long lno, imask, jmask;
631         imask = (1UL<<i);
632         jmask = (1UL<<j);
633
634         for (lno = 0; lno <= cnt; lno++) {
635                 struct lline *ll = sline->lost_head;
636                 sline->p_lno[i] = sline->p_lno[j];
637                 while (ll) {
638                         if (ll->parent_map & jmask)
639                                 ll->parent_map |= imask;
640                         ll = ll->next;
641                 }
642                 if (sline->flag & jmask)
643                         sline->flag |= imask;
644                 sline++;
645         }
646         /* the overall size of the file (sline[cnt]) */
647         sline->p_lno[i] = sline->p_lno[j];
648 }
649
650 static void dump_quoted_path(const char *prefix, const char *path,
651                              const char *c_meta, const char *c_reset)
652 {
653         printf("%s%s", c_meta, prefix);
654         if (quote_c_style(path, NULL, NULL, 0))
655                 quote_c_style(path, NULL, stdout, 0);
656         else
657                 printf("%s", path);
658         printf("%s\n", c_reset);
659 }
660
661 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
662                             int dense, struct rev_info *rev)
663 {
664         struct diff_options *opt = &rev->diffopt;
665         unsigned long result_size, cnt, lno;
666         char *result, *cp;
667         struct sline *sline; /* survived lines */
668         int mode_differs = 0;
669         int i, show_hunks;
670         int working_tree_file = is_null_sha1(elem->sha1);
671         int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
672         mmfile_t result_file;
673
674         context = opt->context;
675         /* Read the result of merge first */
676         if (!working_tree_file)
677                 result = grab_blob(elem->sha1, &result_size);
678         else {
679                 /* Used by diff-tree to read from the working tree */
680                 struct stat st;
681                 int fd = -1;
682
683                 if (lstat(elem->path, &st) < 0)
684                         goto deleted_file;
685
686                 if (S_ISLNK(st.st_mode)) {
687                         size_t len = xsize_t(st.st_size);
688                         result_size = len;
689                         result = xmalloc(len + 1);
690                         if (result_size != readlink(elem->path, result, len)) {
691                                 error("readlink(%s): %s", elem->path,
692                                       strerror(errno));
693                                 return;
694                         }
695                         result[len] = 0;
696                         elem->mode = canon_mode(st.st_mode);
697                 }
698                 else if (0 <= (fd = open(elem->path, O_RDONLY)) &&
699                          !fstat(fd, &st)) {
700                         size_t len = xsize_t(st.st_size);
701                         size_t sz = 0;
702                         int is_file, i;
703
704                         elem->mode = canon_mode(st.st_mode);
705                         /* if symlinks don't work, assume symlink if all parents
706                          * are symlinks
707                          */
708                         is_file = has_symlinks;
709                         for (i = 0; !is_file && i < num_parent; i++)
710                                 is_file = !S_ISLNK(elem->parent[i].mode);
711                         if (!is_file)
712                                 elem->mode = canon_mode(S_IFLNK);
713
714                         result_size = len;
715                         result = xmalloc(len + 1);
716                         while (sz < len) {
717                                 int done = xread(fd, result+sz, len-sz);
718                                 if (done == 0)
719                                         break;
720                                 if (done < 0)
721                                         die("read error '%s'", elem->path);
722                                 sz += done;
723                         }
724                         result[len] = 0;
725                 }
726                 else {
727                 deleted_file:
728                         result_size = 0;
729                         elem->mode = 0;
730                         result = xcalloc(1, 1);
731                 }
732
733                 if (0 <= fd)
734                         close(fd);
735         }
736
737         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
738                 if (*cp == '\n')
739                         cnt++;
740         }
741         if (result_size && result[result_size-1] != '\n')
742                 cnt++; /* incomplete line */
743
744         sline = xcalloc(cnt+2, sizeof(*sline));
745         sline[0].bol = result;
746         for (lno = 0; lno <= cnt + 1; lno++) {
747                 sline[lno].lost_tail = &sline[lno].lost_head;
748                 sline[lno].flag = 0;
749         }
750         for (lno = 0, cp = result; cp < result + result_size; cp++) {
751                 if (*cp == '\n') {
752                         sline[lno].len = cp - sline[lno].bol;
753                         lno++;
754                         if (lno < cnt)
755                                 sline[lno].bol = cp + 1;
756                 }
757         }
758         if (result_size && result[result_size-1] != '\n')
759                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
760
761         result_file.ptr = result;
762         result_file.size = result_size;
763
764         /* Even p_lno[cnt+1] is valid -- that is for the end line number
765          * for deletion hunk at the end.
766          */
767         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
768         for (lno = 0; lno <= cnt; lno++)
769                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
770
771         for (i = 0; i < num_parent; i++) {
772                 int j;
773                 for (j = 0; j < i; j++) {
774                         if (!hashcmp(elem->parent[i].sha1,
775                                      elem->parent[j].sha1)) {
776                                 reuse_combine_diff(sline, cnt, i, j);
777                                 break;
778                         }
779                 }
780                 if (i <= j)
781                         combine_diff(elem->parent[i].sha1, &result_file, sline,
782                                      cnt, i, num_parent);
783                 if (elem->parent[i].mode != elem->mode)
784                         mode_differs = 1;
785         }
786
787         show_hunks = make_hunks(sline, cnt, num_parent, dense);
788
789         if (show_hunks || mode_differs || working_tree_file) {
790                 const char *abb;
791                 int use_color = opt->color_diff;
792                 const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
793                 const char *c_reset = diff_get_color(use_color, DIFF_RESET);
794                 int added = 0;
795                 int deleted = 0;
796
797                 if (rev->loginfo && !rev->no_commit_id)
798                         show_log(rev, opt->msg_sep);
799                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
800                                  elem->path, c_meta, c_reset);
801                 printf("%sindex ", c_meta);
802                 for (i = 0; i < num_parent; i++) {
803                         abb = find_unique_abbrev(elem->parent[i].sha1,
804                                                  abbrev);
805                         printf("%s%s", i ? "," : "", abb);
806                 }
807                 abb = find_unique_abbrev(elem->sha1, abbrev);
808                 printf("..%s%s\n", abb, c_reset);
809
810                 if (mode_differs) {
811                         deleted = !elem->mode;
812
813                         /* We say it was added if nobody had it */
814                         added = !deleted;
815                         for (i = 0; added && i < num_parent; i++)
816                                 if (elem->parent[i].status !=
817                                     DIFF_STATUS_ADDED)
818                                         added = 0;
819                         if (added)
820                                 printf("%snew file mode %06o",
821                                        c_meta, elem->mode);
822                         else {
823                                 if (deleted)
824                                         printf("%sdeleted file ", c_meta);
825                                 printf("mode ");
826                                 for (i = 0; i < num_parent; i++) {
827                                         printf("%s%06o", i ? "," : "",
828                                                elem->parent[i].mode);
829                                 }
830                                 if (elem->mode)
831                                         printf("..%06o", elem->mode);
832                         }
833                         printf("%s\n", c_reset);
834                 }
835                 if (added)
836                         dump_quoted_path("--- /dev/", "null", c_meta, c_reset);
837                 else
838                         dump_quoted_path("--- a/", elem->path, c_meta, c_reset);
839                 if (deleted)
840                         dump_quoted_path("+++ /dev/", "null", c_meta, c_reset);
841                 else
842                         dump_quoted_path("+++ b/", elem->path, c_meta, c_reset);
843                 dump_sline(sline, cnt, num_parent, opt->color_diff);
844         }
845         free(result);
846
847         for (lno = 0; lno < cnt; lno++) {
848                 if (sline[lno].lost_head) {
849                         struct lline *ll = sline[lno].lost_head;
850                         while (ll) {
851                                 struct lline *tmp = ll;
852                                 ll = ll->next;
853                                 free(tmp);
854                         }
855                 }
856         }
857         free(sline[0].p_lno);
858         free(sline);
859 }
860
861 #define COLONS "::::::::::::::::::::::::::::::::"
862
863 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
864 {
865         struct diff_options *opt = &rev->diffopt;
866         int i, offset;
867         const char *prefix;
868         int line_termination, inter_name_termination;
869
870         line_termination = opt->line_termination;
871         inter_name_termination = '\t';
872         if (!line_termination)
873                 inter_name_termination = 0;
874
875         if (rev->loginfo && !rev->no_commit_id)
876                 show_log(rev, opt->msg_sep);
877
878         if (opt->output_format & DIFF_FORMAT_RAW) {
879                 offset = strlen(COLONS) - num_parent;
880                 if (offset < 0)
881                         offset = 0;
882                 prefix = COLONS + offset;
883
884                 /* Show the modes */
885                 for (i = 0; i < num_parent; i++) {
886                         printf("%s%06o", prefix, p->parent[i].mode);
887                         prefix = " ";
888                 }
889                 printf("%s%06o", prefix, p->mode);
890
891                 /* Show sha1's */
892                 for (i = 0; i < num_parent; i++)
893                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
894                                                          opt->abbrev));
895                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
896         }
897
898         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
899                 for (i = 0; i < num_parent; i++)
900                         putchar(p->parent[i].status);
901                 putchar(inter_name_termination);
902         }
903
904         if (line_termination) {
905                 if (quote_c_style(p->path, NULL, NULL, 0))
906                         quote_c_style(p->path, NULL, stdout, 0);
907                 else
908                         printf("%s", p->path);
909                 putchar(line_termination);
910         }
911         else {
912                 printf("%s%c", p->path, line_termination);
913         }
914 }
915
916 void show_combined_diff(struct combine_diff_path *p,
917                        int num_parent,
918                        int dense,
919                        struct rev_info *rev)
920 {
921         struct diff_options *opt = &rev->diffopt;
922         if (!p->len)
923                 return;
924         if (opt->output_format & (DIFF_FORMAT_RAW |
925                                   DIFF_FORMAT_NAME |
926                                   DIFF_FORMAT_NAME_STATUS))
927                 show_raw_diff(p, num_parent, rev);
928         else if (opt->output_format & DIFF_FORMAT_PATCH)
929                 show_patch_diff(p, num_parent, dense, rev);
930 }
931
932 void diff_tree_combined(const unsigned char *sha1,
933                         const unsigned char parent[][20],
934                         int num_parent,
935                         int dense,
936                         struct rev_info *rev)
937 {
938         struct diff_options *opt = &rev->diffopt;
939         struct diff_options diffopts;
940         struct combine_diff_path *p, *paths = NULL;
941         int i, num_paths, needsep, show_log_first;
942
943         diffopts = *opt;
944         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
945         diffopts.recursive = 1;
946
947         show_log_first = !!rev->loginfo && !rev->no_commit_id;
948         needsep = 0;
949         /* find set of paths that everybody touches */
950         for (i = 0; i < num_parent; i++) {
951                 /* show stat against the first parent even
952                  * when doing combined diff.
953                  */
954                 int stat_opt = (opt->output_format &
955                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
956                 if (i == 0 && stat_opt)
957                         diffopts.output_format = stat_opt;
958                 else
959                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
960                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
961                 diffcore_std(&diffopts);
962                 paths = intersect_paths(paths, i, num_parent);
963
964                 if (show_log_first && i == 0) {
965                         show_log(rev, opt->msg_sep);
966                         if (rev->verbose_header && opt->output_format)
967                                 putchar(opt->line_termination);
968                 }
969                 diff_flush(&diffopts);
970         }
971
972         /* find out surviving paths */
973         for (num_paths = 0, p = paths; p; p = p->next) {
974                 if (p->len)
975                         num_paths++;
976         }
977         if (num_paths) {
978                 if (opt->output_format & (DIFF_FORMAT_RAW |
979                                           DIFF_FORMAT_NAME |
980                                           DIFF_FORMAT_NAME_STATUS)) {
981                         for (p = paths; p; p = p->next) {
982                                 if (p->len)
983                                         show_raw_diff(p, num_parent, rev);
984                         }
985                         needsep = 1;
986                 }
987                 else if (opt->output_format &
988                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
989                         needsep = 1;
990                 if (opt->output_format & DIFF_FORMAT_PATCH) {
991                         if (needsep)
992                                 putchar(opt->line_termination);
993                         for (p = paths; p; p = p->next) {
994                                 if (p->len)
995                                         show_patch_diff(p, num_parent, dense,
996                                                         rev);
997                         }
998                 }
999         }
1000
1001         /* Clean things up */
1002         while (paths) {
1003                 struct combine_diff_path *tmp = paths;
1004                 paths = paths->next;
1005                 free(tmp);
1006         }
1007 }
1008
1009 void diff_tree_combined_merge(const unsigned char *sha1,
1010                              int dense, struct rev_info *rev)
1011 {
1012         int num_parent;
1013         const unsigned char (*parent)[20];
1014         struct commit *commit = lookup_commit(sha1);
1015         struct commit_list *parents;
1016
1017         /* count parents */
1018         for (parents = commit->parents, num_parent = 0;
1019              parents;
1020              parents = parents->next, num_parent++)
1021                 ; /* nothing */
1022
1023         parent = xmalloc(num_parent * sizeof(*parent));
1024         for (parents = commit->parents, num_parent = 0;
1025              parents;
1026              parents = parents->next, num_parent++)
1027                 hashcpy((unsigned char*)(parent + num_parent),
1028                         parents->item->object.sha1);
1029         diff_tree_combined(sha1, parent, num_parent, dense, rev);
1030 }