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