Merge branch 'lt/web'
[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 int uninteresting(struct diff_filepair *p)
11 {
12         if (diff_unmodified_pair(p))
13                 return 1;
14         return 0;
15 }
16
17 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
18 {
19         struct diff_queue_struct *q = &diff_queued_diff;
20         struct combine_diff_path *p;
21         int i;
22
23         if (!n) {
24                 struct combine_diff_path *list = NULL, **tail = &list;
25                 for (i = 0; i < q->nr; i++) {
26                         int len;
27                         const char *path;
28                         if (uninteresting(q->queue[i]))
29                                 continue;
30                         path = q->queue[i]->two->path;
31                         len = strlen(path);
32                         p = xmalloc(combine_diff_path_size(num_parent, len));
33                         p->path = (char*) &(p->parent[num_parent]);
34                         memcpy(p->path, path, len);
35                         p->path[len] = 0;
36                         p->len = len;
37                         p->next = NULL;
38                         memset(p->parent, 0,
39                                sizeof(p->parent[0]) * num_parent);
40
41                         memcpy(p->sha1, q->queue[i]->two->sha1, 20);
42                         p->mode = q->queue[i]->two->mode;
43                         memcpy(p->parent[n].sha1, q->queue[i]->one->sha1, 20);
44                         p->parent[n].mode = q->queue[i]->one->mode;
45                         p->parent[n].status = q->queue[i]->status;
46                         *tail = p;
47                         tail = &p->next;
48                 }
49                 return list;
50         }
51
52         for (p = curr; p; p = p->next) {
53                 int found = 0;
54                 if (!p->len)
55                         continue;
56                 for (i = 0; i < q->nr; i++) {
57                         const char *path;
58                         int len;
59
60                         if (uninteresting(q->queue[i]))
61                                 continue;
62                         path = q->queue[i]->two->path;
63                         len = strlen(path);
64                         if (len == p->len && !memcmp(path, p->path, len)) {
65                                 found = 1;
66                                 memcpy(p->parent[n].sha1,
67                                        q->queue[i]->one->sha1, 20);
68                                 p->parent[n].mode = q->queue[i]->one->mode;
69                                 p->parent[n].status = q->queue[i]->status;
70                                 break;
71                         }
72                 }
73                 if (!found)
74                         p->len = 0;
75         }
76         return curr;
77 }
78
79 /* Lines lost from parent */
80 struct lline {
81         struct lline *next;
82         int len;
83         unsigned long parent_map;
84         char line[FLEX_ARRAY];
85 };
86
87 /* Lines surviving in the merge result */
88 struct sline {
89         struct lline *lost_head, **lost_tail;
90         char *bol;
91         int len;
92         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
93          * we did not change it).
94          * bit N is used for "interesting" lines, including context.
95          */
96         unsigned long flag;
97         unsigned long *p_lno;
98 };
99
100 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
101 {
102         char *blob;
103         char type[20];
104         if (!memcmp(sha1, null_sha1, 20)) {
105                 /* deleted blob */
106                 *size = 0;
107                 return xcalloc(1, 1);
108         }
109         blob = read_sha1_file(sha1, type, size);
110         if (strcmp(type, blob_type))
111                 die("object '%s' is not a blob!", sha1_to_hex(sha1));
112         return blob;
113 }
114
115 static void append_lost(struct sline *sline, int n, const char *line, int len)
116 {
117         struct lline *lline;
118         unsigned long this_mask = (1UL<<n);
119         if (line[len-1] == '\n')
120                 len--;
121
122         /* Check to see if we can squash things */
123         if (sline->lost_head) {
124                 struct lline *last_one = NULL;
125                 /* We cannot squash it with earlier one */
126                 for (lline = sline->lost_head;
127                      lline;
128                      lline = lline->next)
129                         if (lline->parent_map & this_mask)
130                                 last_one = lline;
131                 lline = last_one ? last_one->next : sline->lost_head;
132                 while (lline) {
133                         if (lline->len == len &&
134                             !memcmp(lline->line, line, len)) {
135                                 lline->parent_map |= this_mask;
136                                 return;
137                         }
138                         lline = lline->next;
139                 }
140         }
141
142         lline = xmalloc(sizeof(*lline) + len + 1);
143         lline->len = len;
144         lline->next = NULL;
145         lline->parent_map = this_mask;
146         memcpy(lline->line, line, len);
147         lline->line[len] = 0;
148         *sline->lost_tail = lline;
149         sline->lost_tail = &lline->next;
150 }
151
152 struct combine_diff_state {
153         struct xdiff_emit_state xm;
154
155         unsigned int lno;
156         int ob, on, nb, nn;
157         unsigned long nmask;
158         int num_parent;
159         int n;
160         struct sline *sline;
161         struct sline *lost_bucket;
162 };
163
164 static void consume_line(void *state_, char *line, unsigned long len)
165 {
166         struct combine_diff_state *state = state_;
167         if (5 < len && !memcmp("@@ -", line, 4)) {
168                 if (parse_hunk_header(line, len,
169                                       &state->ob, &state->on,
170                                       &state->nb, &state->nn))
171                         return;
172                 state->lno = state->nb;
173                 if (!state->nb)
174                         /* @@ -1,2 +0,0 @@ to remove the
175                          * first two lines...
176                          */
177                         state->nb = 1;
178                 if (state->nn == 0)
179                         /* @@ -X,Y +N,0 @@ removed Y lines
180                          * that would have come *after* line N
181                          * in the result.  Our lost buckets hang
182                          * to the line after the removed lines,
183                          */
184                         state->lost_bucket = &state->sline[state->nb];
185                 else
186                         state->lost_bucket = &state->sline[state->nb-1];
187                 if (!state->sline[state->nb-1].p_lno)
188                         state->sline[state->nb-1].p_lno =
189                                 xcalloc(state->num_parent,
190                                         sizeof(unsigned long));
191                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
192                 return;
193         }
194         if (!state->lost_bucket)
195                 return; /* not in any hunk yet */
196         switch (line[0]) {
197         case '-':
198                 append_lost(state->lost_bucket, state->n, line+1, len-1);
199                 break;
200         case '+':
201                 state->sline[state->lno-1].flag |= state->nmask;
202                 state->lno++;
203                 break;
204         }
205 }
206
207 static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
208                          struct sline *sline, unsigned int cnt, int n,
209                          int num_parent)
210 {
211         unsigned int p_lno, lno;
212         unsigned long nmask = (1UL << n);
213         xpparam_t xpp;
214         xdemitconf_t xecfg;
215         mmfile_t parent_file;
216         xdemitcb_t ecb;
217         struct combine_diff_state state;
218         unsigned long sz;
219
220         if (!cnt)
221                 return; /* result deleted */
222
223         parent_file.ptr = grab_blob(parent, &sz);
224         parent_file.size = sz;
225         xpp.flags = XDF_NEED_MINIMAL;
226         xecfg.ctxlen = 0;
227         xecfg.flags = 0;
228         ecb.outf = xdiff_outf;
229         ecb.priv = &state;
230         memset(&state, 0, sizeof(state));
231         state.xm.consume = consume_line;
232         state.nmask = nmask;
233         state.sline = sline;
234         state.lno = 1;
235         state.num_parent = num_parent;
236         state.n = n;
237
238         xdl_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
239         free(parent_file.ptr);
240
241         /* Assign line numbers for this parent.
242          *
243          * sline[lno].p_lno[n] records the first line number
244          * (counting from 1) for parent N if the final hunk display
245          * started by showing sline[lno] (possibly showing the lost
246          * lines attached to it first).
247          */
248         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
249                 struct lline *ll;
250                 sline[lno].p_lno[n] = p_lno;
251
252                 /* How many lines would this sline advance the p_lno? */
253                 ll = sline[lno].lost_head;
254                 while (ll) {
255                         if (ll->parent_map & nmask)
256                                 p_lno++; /* '-' means parent had it */
257                         ll = ll->next;
258                 }
259                 if (lno < cnt && !(sline[lno].flag & nmask))
260                         p_lno++; /* no '+' means parent had it */
261         }
262         sline[lno].p_lno[n] = p_lno; /* trailer */
263 }
264
265 static unsigned long context = 3;
266 static char combine_marker = '@';
267
268 static int interesting(struct sline *sline, unsigned long all_mask)
269 {
270         /* If some parents lost lines here, or if we have added to
271          * some parent, it is interesting.
272          */
273         return ((sline->flag & all_mask) || sline->lost_head);
274 }
275
276 static unsigned long adjust_hunk_tail(struct sline *sline,
277                                       unsigned long all_mask,
278                                       unsigned long hunk_begin,
279                                       unsigned long i)
280 {
281         /* i points at the first uninteresting line.  If the last line
282          * of the hunk was interesting only because it has some
283          * deletion, then it is not all that interesting for the
284          * purpose of giving trailing context lines.  This is because
285          * we output '-' line and then unmodified sline[i-1] itself in
286          * that case which gives us one extra context line.
287          */
288         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
289                 i--;
290         return i;
291 }
292
293 static unsigned long find_next(struct sline *sline,
294                                unsigned long mark,
295                                unsigned long i,
296                                unsigned long cnt,
297                                int look_for_uninteresting)
298 {
299         /* We have examined up to i-1 and are about to look at i.
300          * Find next interesting or uninteresting line.  Here,
301          * "interesting" does not mean interesting(), but marked by
302          * the give_context() function below (i.e. it includes context
303          * lines that are not interesting to interesting() function
304          * that are surrounded by interesting() ones.
305          */
306         while (i <= cnt)
307                 if (look_for_uninteresting
308                     ? !(sline[i].flag & mark)
309                     : (sline[i].flag & mark))
310                         return i;
311                 else
312                         i++;
313         return i;
314 }
315
316 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
317 {
318         unsigned long all_mask = (1UL<<num_parent) - 1;
319         unsigned long mark = (1UL<<num_parent);
320         unsigned long i;
321
322         /* Two groups of interesting lines may have a short gap of
323          * uninteresting lines.  Connect such groups to give them a
324          * bit of context.
325          *
326          * We first start from what the interesting() function says,
327          * and mark them with "mark", and paint context lines with the
328          * mark.  So interesting() would still say false for such context
329          * lines but they are treated as "interesting" in the end.
330          */
331         i = find_next(sline, mark, 0, cnt, 0);
332         if (cnt < i)
333                 return 0;
334
335         while (i <= cnt) {
336                 unsigned long j = (context < i) ? (i - context) : 0;
337                 unsigned long k;
338
339                 /* Paint a few lines before the first interesting line. */
340                 while (j < i)
341                         sline[j++].flag |= mark;
342
343         again:
344                 /* we know up to i is to be included.  where does the
345                  * next uninteresting one start?
346                  */
347                 j = find_next(sline, mark, i, cnt, 1);
348                 if (cnt < j)
349                         break; /* the rest are all interesting */
350
351                 /* lookahead context lines */
352                 k = find_next(sline, mark, j, cnt, 0);
353                 j = adjust_hunk_tail(sline, all_mask, i, j);
354
355                 if (k < j + context) {
356                         /* k is interesting and [j,k) are not, but
357                          * paint them interesting because the gap is small.
358                          */
359                         while (j < k)
360                                 sline[j++].flag |= mark;
361                         i = k;
362                         goto again;
363                 }
364
365                 /* j is the first uninteresting line and there is
366                  * no overlap beyond it within context lines.  Paint
367                  * the trailing edge a bit.
368                  */
369                 i = k;
370                 k = (j + context < cnt+1) ? j + context : cnt+1;
371                 while (j < k)
372                         sline[j++].flag |= mark;
373         }
374         return 1;
375 }
376
377 static int make_hunks(struct sline *sline, unsigned long cnt,
378                        int num_parent, int dense)
379 {
380         unsigned long all_mask = (1UL<<num_parent) - 1;
381         unsigned long mark = (1UL<<num_parent);
382         unsigned long i;
383         int has_interesting = 0;
384
385         for (i = 0; i <= cnt; i++) {
386                 if (interesting(&sline[i], all_mask))
387                         sline[i].flag |= mark;
388                 else
389                         sline[i].flag &= ~mark;
390         }
391         if (!dense)
392                 return give_context(sline, cnt, num_parent);
393
394         /* Look at each hunk, and if we have changes from only one
395          * parent, or the changes are the same from all but one
396          * parent, mark that uninteresting.
397          */
398         i = 0;
399         while (i <= cnt) {
400                 unsigned long j, hunk_begin, hunk_end;
401                 unsigned long same_diff;
402                 while (i <= cnt && !(sline[i].flag & mark))
403                         i++;
404                 if (cnt < i)
405                         break; /* No more interesting hunks */
406                 hunk_begin = i;
407                 for (j = i + 1; j <= cnt; j++) {
408                         if (!(sline[j].flag & mark)) {
409                                 /* Look beyond the end to see if there
410                                  * is an interesting line after this
411                                  * hunk within context span.
412                                  */
413                                 unsigned long la; /* lookahead */
414                                 int contin = 0;
415                                 la = adjust_hunk_tail(sline, all_mask,
416                                                      hunk_begin, j);
417                                 la = (la + context < cnt + 1) ?
418                                         (la + context) : cnt + 1;
419                                 while (j <= --la) {
420                                         if (sline[la].flag & mark) {
421                                                 contin = 1;
422                                                 break;
423                                         }
424                                 }
425                                 if (!contin)
426                                         break;
427                                 j = la;
428                         }
429                 }
430                 hunk_end = j;
431
432                 /* [i..hunk_end) are interesting.  Now is it really
433                  * interesting?  We check if there are only two versions
434                  * and the result matches one of them.  That is, we look
435                  * at:
436                  *   (+) line, which records lines added to which parents;
437                  *       this line appears in the result.
438                  *   (-) line, which records from what parents the line
439                  *       was removed; this line does not appear in the result.
440                  * then check the set of parents the result has difference
441                  * from, from all lines.  If there are lines that has
442                  * different set of parents that the result has differences
443                  * from, that means we have more than two versions.
444                  *
445                  * Even when we have only two versions, if the result does
446                  * not match any of the parents, the it should be considered
447                  * interesting.  In such a case, we would have all '+' line.
448                  * After passing the above "two versions" test, that would
449                  * appear as "the same set of parents" to be "all parents".
450                  */
451                 same_diff = 0;
452                 has_interesting = 0;
453                 for (j = i; j < hunk_end && !has_interesting; j++) {
454                         unsigned long this_diff = sline[j].flag & all_mask;
455                         struct lline *ll = sline[j].lost_head;
456                         if (this_diff) {
457                                 /* This has some changes.  Is it the
458                                  * same as others?
459                                  */
460                                 if (!same_diff)
461                                         same_diff = this_diff;
462                                 else if (same_diff != this_diff) {
463                                         has_interesting = 1;
464                                         break;
465                                 }
466                         }
467                         while (ll && !has_interesting) {
468                                 /* Lost this line from these parents;
469                                  * who are they?  Are they the same?
470                                  */
471                                 this_diff = ll->parent_map;
472                                 if (!same_diff)
473                                         same_diff = this_diff;
474                                 else if (same_diff != this_diff) {
475                                         has_interesting = 1;
476                                 }
477                                 ll = ll->next;
478                         }
479                 }
480
481                 if (!has_interesting && same_diff != all_mask) {
482                         /* This hunk is not that interesting after all */
483                         for (j = hunk_begin; j < hunk_end; j++)
484                                 sline[j].flag &= ~mark;
485                 }
486                 i = hunk_end;
487         }
488
489         has_interesting = give_context(sline, cnt, num_parent);
490         return has_interesting;
491 }
492
493 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n)
494 {
495         l0 = sline[l0].p_lno[n];
496         l1 = sline[l1].p_lno[n];
497         printf(" -%lu,%lu", l0, l1-l0);
498 }
499
500 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent)
501 {
502         unsigned long mark = (1UL<<num_parent);
503         int i;
504         unsigned long lno = 0;
505
506         if (!cnt)
507                 return; /* result deleted */
508
509         while (1) {
510                 struct sline *sl = &sline[lno];
511                 unsigned long hunk_end;
512                 unsigned long rlines;
513                 while (lno <= cnt && !(sline[lno].flag & mark))
514                         lno++;
515                 if (cnt < lno)
516                         break;
517                 else {
518                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
519                                 if (!(sline[hunk_end].flag & mark))
520                                         break;
521                 }
522                 rlines = hunk_end - lno;
523                 if (cnt < hunk_end)
524                         rlines--; /* pointing at the last delete hunk */
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                 putchar('\n');
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                                 for (j = 0; j < num_parent; j++) {
539                                         if (ll->parent_map & (1UL<<j))
540                                                 putchar('-');
541                                         else
542                                                 putchar(' ');
543                                 }
544                                 puts(ll->line);
545                                 ll = ll->next;
546                         }
547                         if (cnt < lno)
548                                 break;
549                         p_mask = 1;
550                         for (j = 0; j < num_parent; j++) {
551                                 if (p_mask & sl->flag)
552                                         putchar('+');
553                                 else
554                                         putchar(' ');
555                                 p_mask <<= 1;
556                         }
557                         printf("%.*s\n", sl->len, sl->bol);
558                 }
559         }
560 }
561
562 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
563                                int i, int j)
564 {
565         /* We have already examined parent j and we know parent i
566          * and parent j are the same, so reuse the combined result
567          * of parent j for parent i.
568          */
569         unsigned long lno, imask, jmask;
570         imask = (1UL<<i);
571         jmask = (1UL<<j);
572
573         for (lno = 0; lno <= cnt; lno++) {
574                 struct lline *ll = sline->lost_head;
575                 sline->p_lno[i] = sline->p_lno[j];
576                 while (ll) {
577                         if (ll->parent_map & jmask)
578                                 ll->parent_map |= imask;
579                         ll = ll->next;
580                 }
581                 if (sline->flag & jmask)
582                         sline->flag |= imask;
583                 sline++;
584         }
585         /* the overall size of the file (sline[cnt]) */
586         sline->p_lno[i] = sline->p_lno[j];
587 }
588
589 static void dump_quoted_path(const char *prefix, const char *path)
590 {
591         fputs(prefix, stdout);
592         if (quote_c_style(path, NULL, NULL, 0))
593                 quote_c_style(path, NULL, stdout, 0);
594         else
595                 printf("%s", path);
596         putchar('\n');
597 }
598
599 static int show_patch_diff(struct combine_diff_path *elem, int num_parent,
600                            int dense, struct rev_info *rev)
601 {
602         struct diff_options *opt = &rev->diffopt;
603         unsigned long result_size, cnt, lno;
604         char *result, *cp;
605         struct sline *sline; /* survived lines */
606         int mode_differs = 0;
607         int i, show_hunks, shown_header = 0;
608         int working_tree_file = !memcmp(elem->sha1, null_sha1, 20);
609         int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
610         mmfile_t result_file;
611
612         context = opt->context;
613         /* Read the result of merge first */
614         if (!working_tree_file)
615                 result = grab_blob(elem->sha1, &result_size);
616         else {
617                 /* Used by diff-tree to read from the working tree */
618                 struct stat st;
619                 int fd;
620                 if (0 <= (fd = open(elem->path, O_RDONLY)) &&
621                     !fstat(fd, &st)) {
622                         int len = st.st_size;
623                         int sz = 0;
624
625                         elem->mode = canon_mode(st.st_mode);
626                         result_size = len;
627                         result = xmalloc(len + 1);
628                         while (sz < len) {
629                                 int done = xread(fd, result+sz, len-sz);
630                                 if (done == 0)
631                                         break;
632                                 if (done < 0)
633                                         die("read error '%s'", elem->path);
634                                 sz += done;
635                         }
636                         result[len] = 0;
637                 }
638                 else {
639                         /* deleted file */
640                         result_size = 0;
641                         elem->mode = 0;
642                         result = xcalloc(1, 1);
643                 }
644                 if (0 <= fd)
645                         close(fd);
646         }
647
648         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
649                 if (*cp == '\n')
650                         cnt++;
651         }
652         if (result_size && result[result_size-1] != '\n')
653                 cnt++; /* incomplete line */
654
655         sline = xcalloc(cnt+2, sizeof(*sline));
656         sline[0].bol = result;
657         for (lno = 0; lno <= cnt + 1; lno++) {
658                 sline[lno].lost_tail = &sline[lno].lost_head;
659                 sline[lno].flag = 0;
660         }
661         for (lno = 0, cp = result; cp < result + result_size; cp++) {
662                 if (*cp == '\n') {
663                         sline[lno].len = cp - sline[lno].bol;
664                         lno++;
665                         if (lno < cnt)
666                                 sline[lno].bol = cp + 1;
667                 }
668         }
669         if (result_size && result[result_size-1] != '\n')
670                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
671
672         result_file.ptr = result;
673         result_file.size = result_size;
674
675         /* Even p_lno[cnt+1] is valid -- that is for the end line number
676          * for deletion hunk at the end.
677          */
678         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
679         for (lno = 0; lno <= cnt; lno++)
680                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
681
682         for (i = 0; i < num_parent; i++) {
683                 int j;
684                 for (j = 0; j < i; j++) {
685                         if (!memcmp(elem->parent[i].sha1,
686                                     elem->parent[j].sha1, 20)) {
687                                 reuse_combine_diff(sline, cnt, i, j);
688                                 break;
689                         }
690                 }
691                 if (i <= j)
692                         combine_diff(elem->parent[i].sha1, &result_file, sline,
693                                      cnt, i, num_parent);
694                 if (elem->parent[i].mode != elem->mode)
695                         mode_differs = 1;
696         }
697
698         show_hunks = make_hunks(sline, cnt, num_parent, dense);
699
700         if (show_hunks || mode_differs || working_tree_file) {
701                 const char *abb;
702
703                 if (rev->loginfo)
704                         show_log(rev, opt->msg_sep);
705                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ", elem->path);
706                 printf("index ");
707                 for (i = 0; i < num_parent; i++) {
708                         abb = find_unique_abbrev(elem->parent[i].sha1,
709                                                  abbrev);
710                         printf("%s%s", i ? "," : "", abb);
711                 }
712                 abb = find_unique_abbrev(elem->sha1, abbrev);
713                 printf("..%s\n", abb);
714
715                 if (mode_differs) {
716                         int added = !!elem->mode;
717                         for (i = 0; added && i < num_parent; i++)
718                                 if (elem->parent[i].status !=
719                                     DIFF_STATUS_ADDED)
720                                         added = 0;
721                         if (added)
722                                 printf("new file mode %06o", elem->mode);
723                         else {
724                                 if (!elem->mode)
725                                         printf("deleted file ");
726                                 printf("mode ");
727                                 for (i = 0; i < num_parent; i++) {
728                                         printf("%s%06o", i ? "," : "",
729                                                elem->parent[i].mode);
730                                 }
731                                 if (elem->mode)
732                                         printf("..%06o", elem->mode);
733                         }
734                         putchar('\n');
735                 }
736                 dump_quoted_path("--- a/", elem->path);
737                 dump_quoted_path("+++ b/", elem->path);
738                 dump_sline(sline, cnt, num_parent);
739         }
740         free(result);
741
742         for (lno = 0; lno < cnt; lno++) {
743                 if (sline[lno].lost_head) {
744                         struct lline *ll = sline[lno].lost_head;
745                         while (ll) {
746                                 struct lline *tmp = ll;
747                                 ll = ll->next;
748                                 free(tmp);
749                         }
750                 }
751         }
752         free(sline[0].p_lno);
753         free(sline);
754         return shown_header;
755 }
756
757 #define COLONS "::::::::::::::::::::::::::::::::"
758
759 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
760 {
761         struct diff_options *opt = &rev->diffopt;
762         int i, offset;
763         const char *prefix;
764         int line_termination, inter_name_termination;
765
766         line_termination = opt->line_termination;
767         inter_name_termination = '\t';
768         if (!line_termination)
769                 inter_name_termination = 0;
770
771         if (rev->loginfo)
772                 show_log(rev, opt->msg_sep);
773
774         if (opt->output_format & DIFF_FORMAT_RAW) {
775                 offset = strlen(COLONS) - num_parent;
776                 if (offset < 0)
777                         offset = 0;
778                 prefix = COLONS + offset;
779
780                 /* Show the modes */
781                 for (i = 0; i < num_parent; i++) {
782                         printf("%s%06o", prefix, p->parent[i].mode);
783                         prefix = " ";
784                 }
785                 printf("%s%06o", prefix, p->mode);
786
787                 /* Show sha1's */
788                 for (i = 0; i < num_parent; i++)
789                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
790                                                          opt->abbrev));
791                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
792         }
793
794         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
795                 for (i = 0; i < num_parent; i++)
796                         putchar(p->parent[i].status);
797                 putchar(inter_name_termination);
798         }
799
800         if (line_termination) {
801                 if (quote_c_style(p->path, NULL, NULL, 0))
802                         quote_c_style(p->path, NULL, stdout, 0);
803                 else
804                         printf("%s", p->path);
805                 putchar(line_termination);
806         }
807         else {
808                 printf("%s%c", p->path, line_termination);
809         }
810 }
811
812 void show_combined_diff(struct combine_diff_path *p,
813                        int num_parent,
814                        int dense,
815                        struct rev_info *rev)
816 {
817         struct diff_options *opt = &rev->diffopt;
818         if (!p->len)
819                 return;
820         if (opt->output_format & (DIFF_FORMAT_RAW |
821                                   DIFF_FORMAT_NAME |
822                                   DIFF_FORMAT_NAME_STATUS)) {
823                 show_raw_diff(p, num_parent, rev);
824         } else if (opt->output_format & DIFF_FORMAT_PATCH) {
825                 show_patch_diff(p, num_parent, dense, rev);
826         }
827 }
828
829 void diff_tree_combined(const unsigned char *sha1,
830                         const unsigned char parent[][20],
831                         int num_parent,
832                         int dense,
833                         struct rev_info *rev)
834 {
835         struct diff_options *opt = &rev->diffopt;
836         struct diff_options diffopts;
837         struct combine_diff_path *p, *paths = NULL;
838         int i, num_paths, needsep, show_log_first;
839
840         diffopts = *opt;
841         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
842         diffopts.recursive = 1;
843
844         show_log_first = !!rev->loginfo;
845         needsep = 0;
846         /* find set of paths that everybody touches */
847         for (i = 0; i < num_parent; i++) {
848                 /* show stat against the first parent even
849                  * when doing combined diff.
850                  */
851                 if (i == 0 && opt->output_format & DIFF_FORMAT_DIFFSTAT)
852                         diffopts.output_format = DIFF_FORMAT_DIFFSTAT;
853                 else
854                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
855                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
856                 diffcore_std(&diffopts);
857                 paths = intersect_paths(paths, i, num_parent);
858
859                 if (show_log_first && i == 0) {
860                         show_log(rev, opt->msg_sep);
861                         if (rev->verbose_header && opt->output_format)
862                                 putchar(opt->line_termination);
863                 }
864                 diff_flush(&diffopts);
865         }
866
867         /* find out surviving paths */
868         for (num_paths = 0, p = paths; p; p = p->next) {
869                 if (p->len)
870                         num_paths++;
871         }
872         if (num_paths) {
873                 if (opt->output_format & (DIFF_FORMAT_RAW |
874                                           DIFF_FORMAT_NAME |
875                                           DIFF_FORMAT_NAME_STATUS)) {
876                         for (p = paths; p; p = p->next) {
877                                 if (p->len)
878                                         show_raw_diff(p, num_parent, rev);
879                         }
880                         needsep = 1;
881                 }
882                 else if (opt->output_format & DIFF_FORMAT_DIFFSTAT)
883                         needsep = 1;
884                 if (opt->output_format & DIFF_FORMAT_PATCH) {
885                         if (needsep)
886                                 putchar(opt->line_termination);
887                         for (p = paths; p; p = p->next) {
888                                 if (p->len)
889                                         show_patch_diff(p, num_parent, dense,
890                                                         rev);
891                         }
892                 }
893         }
894
895         /* Clean things up */
896         while (paths) {
897                 struct combine_diff_path *tmp = paths;
898                 paths = paths->next;
899                 free(tmp);
900         }
901 }
902
903 void diff_tree_combined_merge(const unsigned char *sha1,
904                              int dense, struct rev_info *rev)
905 {
906         int num_parent;
907         const unsigned char (*parent)[20];
908         struct commit *commit = lookup_commit(sha1);
909         struct commit_list *parents;
910
911         /* count parents */
912         for (parents = commit->parents, num_parent = 0;
913              parents;
914              parents = parents->next, num_parent++)
915                 ; /* nothing */
916
917         parent = xmalloc(num_parent * sizeof(*parent));
918         for (parents = commit->parents, num_parent = 0;
919              parents;
920              parents = parents->next, num_parent++)
921                 memcpy(parent + num_parent, parents->item->object.sha1, 20);
922         diff_tree_combined(sha1, parent, num_parent, dense, rev);
923 }