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