fast-export: ensure that a renamed file is printed after all references
[git/dscho.git] / combine-diff.c
blob3480dae82416bda357dee2f0d545ac6dadc6a26f
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 #include "refs.h"
11 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
13         struct diff_queue_struct *q = &diff_queued_diff;
14         struct combine_diff_path *p;
15         int i;
17         if (!n) {
18                 struct combine_diff_path *list = NULL, **tail = &list;
19                 for (i = 0; i < q->nr; i++) {
20                         int len;
21                         const char *path;
22                         if (diff_unmodified_pair(q->queue[i]))
23                                 continue;
24                         path = q->queue[i]->two->path;
25                         len = strlen(path);
26                         p = xmalloc(combine_diff_path_size(num_parent, len));
27                         p->path = (char *) &(p->parent[num_parent]);
28                         memcpy(p->path, path, len);
29                         p->path[len] = 0;
30                         p->len = len;
31                         p->next = NULL;
32                         memset(p->parent, 0,
33                                sizeof(p->parent[0]) * num_parent);
35                         hashcpy(p->sha1, q->queue[i]->two->sha1);
36                         p->mode = q->queue[i]->two->mode;
37                         hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
38                         p->parent[n].mode = q->queue[i]->one->mode;
39                         p->parent[n].status = q->queue[i]->status;
40                         *tail = p;
41                         tail = &p->next;
42                 }
43                 return list;
44         }
46         for (p = curr; p; p = p->next) {
47                 int found = 0;
48                 if (!p->len)
49                         continue;
50                 for (i = 0; i < q->nr; i++) {
51                         const char *path;
52                         int len;
54                         if (diff_unmodified_pair(q->queue[i]))
55                                 continue;
56                         path = q->queue[i]->two->path;
57                         len = strlen(path);
58                         if (len == p->len && !memcmp(path, p->path, len)) {
59                                 found = 1;
60                                 hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
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;
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];
80 /* Lines surviving in the merge result */
81 struct sline {
82         struct lline *lost_head, **lost_tail;
83         struct lline *next_lost;
84         char *bol;
85         int len;
86         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
87          * we did not change it).
88          * bit N is used for "interesting" lines, including context.
89          * bit (N+1) is used for "do not show deletion before this".
90          */
91         unsigned long flag;
92         unsigned long *p_lno;
95 static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
97         char *blob;
98         enum object_type type;
100         if (S_ISGITLINK(mode)) {
101                 blob = xmalloc(100);
102                 *size = snprintf(blob, 100,
103                                  "Subproject commit %s\n", sha1_to_hex(sha1));
104         } else if (is_null_sha1(sha1)) {
105                 /* deleted blob */
106                 *size = 0;
107                 return xcalloc(1, 1);
108         } else {
109                 blob = read_sha1_file(sha1, &type, size);
110                 if (type != OBJ_BLOB)
111                         die("object '%s' is not a blob!", sha1_to_hex(sha1));
112         }
113         return blob;
116 static void append_lost(struct sline *sline, int n, const char *line, int len)
118         struct lline *lline;
119         unsigned long this_mask = (1UL<<n);
120         if (line[len-1] == '\n')
121                 len--;
123         /* Check to see if we can squash things */
124         if (sline->lost_head) {
125                 lline = sline->next_lost;
126                 while (lline) {
127                         if (lline->len == len &&
128                             !memcmp(lline->line, line, len)) {
129                                 lline->parent_map |= this_mask;
130                                 sline->next_lost = lline->next;
131                                 return;
132                         }
133                         lline = lline->next;
134                 }
135         }
137         lline = xmalloc(sizeof(*lline) + len + 1);
138         lline->len = len;
139         lline->next = NULL;
140         lline->parent_map = this_mask;
141         memcpy(lline->line, line, len);
142         lline->line[len] = 0;
143         *sline->lost_tail = lline;
144         sline->lost_tail = &lline->next;
145         sline->next_lost = NULL;
148 struct combine_diff_state {
149         unsigned int lno;
150         int ob, on, nb, nn;
151         unsigned long nmask;
152         int num_parent;
153         int n;
154         struct sline *sline;
155         struct sline *lost_bucket;
158 static void consume_line(void *state_, char *line, unsigned long len)
160         struct combine_diff_state *state = state_;
161         if (5 < len && !memcmp("@@ -", line, 4)) {
162                 if (parse_hunk_header(line, len,
163                                       &state->ob, &state->on,
164                                       &state->nb, &state->nn))
165                         return;
166                 state->lno = state->nb;
167                 if (state->nn == 0) {
168                         /* @@ -X,Y +N,0 @@ removed Y lines
169                          * that would have come *after* line N
170                          * in the result.  Our lost buckets hang
171                          * to the line after the removed lines,
172                          *
173                          * Note that this is correct even when N == 0,
174                          * in which case the hunk removes the first
175                          * line in the file.
176                          */
177                         state->lost_bucket = &state->sline[state->nb];
178                         if (!state->nb)
179                                 state->nb = 1;
180                 } else {
181                         state->lost_bucket = &state->sline[state->nb-1];
182                 }
183                 if (!state->sline[state->nb-1].p_lno)
184                         state->sline[state->nb-1].p_lno =
185                                 xcalloc(state->num_parent,
186                                         sizeof(unsigned long));
187                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
188                 state->lost_bucket->next_lost = state->lost_bucket->lost_head;
189                 return;
190         }
191         if (!state->lost_bucket)
192                 return; /* not in any hunk yet */
193         switch (line[0]) {
194         case '-':
195                 append_lost(state->lost_bucket, state->n, line+1, len-1);
196                 break;
197         case '+':
198                 state->sline[state->lno-1].flag |= state->nmask;
199                 state->lno++;
200                 break;
201         }
204 static void combine_diff(const unsigned char *parent, unsigned int mode,
205                          mmfile_t *result_file,
206                          struct sline *sline, unsigned int cnt, int n,
207                          int num_parent, int result_deleted)
209         unsigned int p_lno, lno;
210         unsigned long nmask = (1UL << n);
211         xpparam_t xpp;
212         xdemitconf_t xecfg;
213         mmfile_t parent_file;
214         xdemitcb_t ecb;
215         struct combine_diff_state state;
216         unsigned long sz;
218         if (result_deleted)
219                 return; /* result deleted */
221         parent_file.ptr = grab_blob(parent, mode, &sz);
222         parent_file.size = sz;
223         memset(&xpp, 0, sizeof(xpp));
224         xpp.flags = XDF_NEED_MINIMAL;
225         memset(&xecfg, 0, sizeof(xecfg));
226         memset(&state, 0, sizeof(state));
227         state.nmask = nmask;
228         state.sline = sline;
229         state.lno = 1;
230         state.num_parent = num_parent;
231         state.n = n;
233         xdi_diff_outf(&parent_file, result_file, consume_line, &state,
234                       &xpp, &xecfg, &ecb);
235         free(parent_file.ptr);
237         /* Assign line numbers for this parent.
238          *
239          * sline[lno].p_lno[n] records the first line number
240          * (counting from 1) for parent N if the final hunk display
241          * started by showing sline[lno] (possibly showing the lost
242          * lines attached to it first).
243          */
244         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
245                 struct lline *ll;
246                 sline[lno].p_lno[n] = p_lno;
248                 /* How many lines would this sline advance the p_lno? */
249                 ll = sline[lno].lost_head;
250                 while (ll) {
251                         if (ll->parent_map & nmask)
252                                 p_lno++; /* '-' means parent had it */
253                         ll = ll->next;
254                 }
255                 if (lno < cnt && !(sline[lno].flag & nmask))
256                         p_lno++; /* no '+' means parent had it */
257         }
258         sline[lno].p_lno[n] = p_lno; /* trailer */
261 static unsigned long context = 3;
262 static char combine_marker = '@';
264 static int interesting(struct sline *sline, unsigned long all_mask)
266         /* If some parents lost lines here, or if we have added to
267          * some parent, it is interesting.
268          */
269         return ((sline->flag & all_mask) || sline->lost_head);
272 static unsigned long adjust_hunk_tail(struct sline *sline,
273                                       unsigned long all_mask,
274                                       unsigned long hunk_begin,
275                                       unsigned long i)
277         /* i points at the first uninteresting line.  If the last line
278          * of the hunk was interesting only because it has some
279          * deletion, then it is not all that interesting for the
280          * purpose of giving trailing context lines.  This is because
281          * we output '-' line and then unmodified sline[i-1] itself in
282          * that case which gives us one extra context line.
283          */
284         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
285                 i--;
286         return i;
289 static unsigned long find_next(struct sline *sline,
290                                unsigned long mark,
291                                unsigned long i,
292                                unsigned long cnt,
293                                int look_for_uninteresting)
295         /* We have examined up to i-1 and are about to look at i.
296          * Find next interesting or uninteresting line.  Here,
297          * "interesting" does not mean interesting(), but marked by
298          * the give_context() function below (i.e. it includes context
299          * lines that are not interesting to interesting() function
300          * that are surrounded by interesting() ones.
301          */
302         while (i <= cnt)
303                 if (look_for_uninteresting
304                     ? !(sline[i].flag & mark)
305                     : (sline[i].flag & mark))
306                         return i;
307                 else
308                         i++;
309         return i;
312 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
314         unsigned long all_mask = (1UL<<num_parent) - 1;
315         unsigned long mark = (1UL<<num_parent);
316         unsigned long no_pre_delete = (2UL<<num_parent);
317         unsigned long i;
319         /* Two groups of interesting lines may have a short gap of
320          * uninteresting lines.  Connect such groups to give them a
321          * bit of context.
322          *
323          * We first start from what the interesting() function says,
324          * and mark them with "mark", and paint context lines with the
325          * mark.  So interesting() would still say false for such context
326          * lines but they are treated as "interesting" in the end.
327          */
328         i = find_next(sline, mark, 0, cnt, 0);
329         if (cnt < i)
330                 return 0;
332         while (i <= cnt) {
333                 unsigned long j = (context < i) ? (i - context) : 0;
334                 unsigned long k;
336                 /* Paint a few lines before the first interesting line. */
337                 while (j < i)
338                         sline[j++].flag |= mark | no_pre_delete;
340         again:
341                 /* we know up to i is to be included.  where does the
342                  * next uninteresting one start?
343                  */
344                 j = find_next(sline, mark, i, cnt, 1);
345                 if (cnt < j)
346                         break; /* the rest are all interesting */
348                 /* lookahead context lines */
349                 k = find_next(sline, mark, j, cnt, 0);
350                 j = adjust_hunk_tail(sline, all_mask, i, j);
352                 if (k < j + context) {
353                         /* k is interesting and [j,k) are not, but
354                          * paint them interesting because the gap is small.
355                          */
356                         while (j < k)
357                                 sline[j++].flag |= mark;
358                         i = k;
359                         goto again;
360                 }
362                 /* j is the first uninteresting line and there is
363                  * no overlap beyond it within context lines.  Paint
364                  * the trailing edge a bit.
365                  */
366                 i = k;
367                 k = (j + context < cnt+1) ? j + context : cnt+1;
368                 while (j < k)
369                         sline[j++].flag |= mark;
370         }
371         return 1;
374 static int make_hunks(struct sline *sline, unsigned long cnt,
375                        int num_parent, int dense)
377         unsigned long all_mask = (1UL<<num_parent) - 1;
378         unsigned long mark = (1UL<<num_parent);
379         unsigned long i;
380         int has_interesting = 0;
382         for (i = 0; i <= cnt; i++) {
383                 if (interesting(&sline[i], all_mask))
384                         sline[i].flag |= mark;
385                 else
386                         sline[i].flag &= ~mark;
387         }
388         if (!dense)
389                 return give_context(sline, cnt, num_parent);
391         /* Look at each hunk, and if we have changes from only one
392          * parent, or the changes are the same from all but one
393          * parent, mark that uninteresting.
394          */
395         i = 0;
396         while (i <= cnt) {
397                 unsigned long j, hunk_begin, hunk_end;
398                 unsigned long same_diff;
399                 while (i <= cnt && !(sline[i].flag & mark))
400                         i++;
401                 if (cnt < i)
402                         break; /* No more interesting hunks */
403                 hunk_begin = i;
404                 for (j = i + 1; j <= cnt; j++) {
405                         if (!(sline[j].flag & mark)) {
406                                 /* Look beyond the end to see if there
407                                  * is an interesting line after this
408                                  * hunk within context span.
409                                  */
410                                 unsigned long la; /* lookahead */
411                                 int contin = 0;
412                                 la = adjust_hunk_tail(sline, all_mask,
413                                                      hunk_begin, j);
414                                 la = (la + context < cnt + 1) ?
415                                         (la + context) : cnt + 1;
416                                 while (j <= --la) {
417                                         if (sline[la].flag & mark) {
418                                                 contin = 1;
419                                                 break;
420                                         }
421                                 }
422                                 if (!contin)
423                                         break;
424                                 j = la;
425                         }
426                 }
427                 hunk_end = j;
429                 /* [i..hunk_end) are interesting.  Now is it really
430                  * interesting?  We check if there are only two versions
431                  * and the result matches one of them.  That is, we look
432                  * at:
433                  *   (+) line, which records lines added to which parents;
434                  *       this line appears in the result.
435                  *   (-) line, which records from what parents the line
436                  *       was removed; this line does not appear in the result.
437                  * then check the set of parents the result has difference
438                  * from, from all lines.  If there are lines that has
439                  * different set of parents that the result has differences
440                  * from, that means we have more than two versions.
441                  *
442                  * Even when we have only two versions, if the result does
443                  * not match any of the parents, the it should be considered
444                  * interesting.  In such a case, we would have all '+' line.
445                  * After passing the above "two versions" test, that would
446                  * appear as "the same set of parents" to be "all parents".
447                  */
448                 same_diff = 0;
449                 has_interesting = 0;
450                 for (j = i; j < hunk_end && !has_interesting; j++) {
451                         unsigned long this_diff = sline[j].flag & all_mask;
452                         struct lline *ll = sline[j].lost_head;
453                         if (this_diff) {
454                                 /* This has some changes.  Is it the
455                                  * same as others?
456                                  */
457                                 if (!same_diff)
458                                         same_diff = this_diff;
459                                 else if (same_diff != this_diff) {
460                                         has_interesting = 1;
461                                         break;
462                                 }
463                         }
464                         while (ll && !has_interesting) {
465                                 /* Lost this line from these parents;
466                                  * who are they?  Are they the same?
467                                  */
468                                 this_diff = ll->parent_map;
469                                 if (!same_diff)
470                                         same_diff = this_diff;
471                                 else if (same_diff != this_diff) {
472                                         has_interesting = 1;
473                                 }
474                                 ll = ll->next;
475                         }
476                 }
478                 if (!has_interesting && same_diff != all_mask) {
479                         /* This hunk is not that interesting after all */
480                         for (j = hunk_begin; j < hunk_end; j++)
481                                 sline[j].flag &= ~mark;
482                 }
483                 i = hunk_end;
484         }
486         has_interesting = give_context(sline, cnt, num_parent);
487         return has_interesting;
490 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
492         l0 = sline[l0].p_lno[n];
493         l1 = sline[l1].p_lno[n];
494         printf(" -%lu,%lu", l0, l1-l0-null_context);
497 static int hunk_comment_line(const char *bol)
499         int ch;
501         if (!bol)
502                 return 0;
503         ch = *bol & 0xff;
504         return (isalpha(ch) || ch == '_' || ch == '$');
507 static void show_line_to_eol(const char *line, int len, const char *reset)
509         int saw_cr_at_eol = 0;
510         if (len < 0)
511                 len = strlen(line);
512         saw_cr_at_eol = (len && line[len-1] == '\r');
514         printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
515                reset,
516                saw_cr_at_eol ? "\r" : "");
519 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
520                        int use_color, int result_deleted)
522         unsigned long mark = (1UL<<num_parent);
523         unsigned long no_pre_delete = (2UL<<num_parent);
524         int i;
525         unsigned long lno = 0;
526         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
527         const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
528         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
529         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
530         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
531         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
533         if (result_deleted)
534                 return; /* result deleted */
536         while (1) {
537                 unsigned long hunk_end;
538                 unsigned long rlines;
539                 const char *hunk_comment = NULL;
540                 unsigned long null_context = 0;
542                 while (lno <= cnt && !(sline[lno].flag & mark)) {
543                         if (hunk_comment_line(sline[lno].bol))
544                                 hunk_comment = sline[lno].bol;
545                         lno++;
546                 }
547                 if (cnt < lno)
548                         break;
549                 else {
550                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
551                                 if (!(sline[hunk_end].flag & mark))
552                                         break;
553                 }
554                 rlines = hunk_end - lno;
555                 if (cnt < hunk_end)
556                         rlines--; /* pointing at the last delete hunk */
558                 if (!context) {
559                         /*
560                          * Even when running with --unified=0, all
561                          * lines in the hunk needs to be processed in
562                          * the loop below in order to show the
563                          * deletion recorded in lost_head.  However,
564                          * we do not want to show the resulting line
565                          * with all blank context markers in such a
566                          * case.  Compensate.
567                          */
568                         unsigned long j;
569                         for (j = lno; j < hunk_end; j++)
570                                 if (!(sline[j].flag & (mark-1)))
571                                         null_context++;
572                         rlines -= null_context;
573                 }
575                 fputs(c_frag, stdout);
576                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
577                 for (i = 0; i < num_parent; i++)
578                         show_parent_lno(sline, lno, hunk_end, i, null_context);
579                 printf(" +%lu,%lu ", lno+1, rlines);
580                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
582                 if (hunk_comment) {
583                         int comment_end = 0;
584                         for (i = 0; i < 40; i++) {
585                                 int ch = hunk_comment[i] & 0xff;
586                                 if (!ch || ch == '\n')
587                                         break;
588                                 if (!isspace(ch))
589                                     comment_end = i;
590                         }
591                         if (comment_end)
592                                 printf("%s%s %s%s", c_reset,
593                                                     c_plain, c_reset,
594                                                     c_func);
595                         for (i = 0; i < comment_end; i++)
596                                 putchar(hunk_comment[i]);
597                 }
599                 printf("%s\n", c_reset);
600                 while (lno < hunk_end) {
601                         struct lline *ll;
602                         int j;
603                         unsigned long p_mask;
604                         struct sline *sl = &sline[lno++];
605                         ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
606                         while (ll) {
607                                 fputs(c_old, stdout);
608                                 for (j = 0; j < num_parent; j++) {
609                                         if (ll->parent_map & (1UL<<j))
610                                                 putchar('-');
611                                         else
612                                                 putchar(' ');
613                                 }
614                                 show_line_to_eol(ll->line, -1, c_reset);
615                                 ll = ll->next;
616                         }
617                         if (cnt < lno)
618                                 break;
619                         p_mask = 1;
620                         if (!(sl->flag & (mark-1))) {
621                                 /*
622                                  * This sline was here to hang the
623                                  * lost lines in front of it.
624                                  */
625                                 if (!context)
626                                         continue;
627                                 fputs(c_plain, stdout);
628                         }
629                         else
630                                 fputs(c_new, stdout);
631                         for (j = 0; j < num_parent; j++) {
632                                 if (p_mask & sl->flag)
633                                         putchar('+');
634                                 else
635                                         putchar(' ');
636                                 p_mask <<= 1;
637                         }
638                         show_line_to_eol(sl->bol, sl->len, c_reset);
639                 }
640         }
643 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
644                                int i, int j)
646         /* We have already examined parent j and we know parent i
647          * and parent j are the same, so reuse the combined result
648          * of parent j for parent i.
649          */
650         unsigned long lno, imask, jmask;
651         imask = (1UL<<i);
652         jmask = (1UL<<j);
654         for (lno = 0; lno <= cnt; lno++) {
655                 struct lline *ll = sline->lost_head;
656                 sline->p_lno[i] = sline->p_lno[j];
657                 while (ll) {
658                         if (ll->parent_map & jmask)
659                                 ll->parent_map |= imask;
660                         ll = ll->next;
661                 }
662                 if (sline->flag & jmask)
663                         sline->flag |= imask;
664                 sline++;
665         }
666         /* the overall size of the file (sline[cnt]) */
667         sline->p_lno[i] = sline->p_lno[j];
670 static void dump_quoted_path(const char *head,
671                              const char *prefix,
672                              const char *path,
673                              const char *c_meta, const char *c_reset)
675         static struct strbuf buf = STRBUF_INIT;
677         strbuf_reset(&buf);
678         strbuf_addstr(&buf, c_meta);
679         strbuf_addstr(&buf, head);
680         quote_two_c_style(&buf, prefix, path, 0);
681         strbuf_addstr(&buf, c_reset);
682         puts(buf.buf);
685 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
686                             int dense, struct rev_info *rev)
688         struct diff_options *opt = &rev->diffopt;
689         unsigned long result_size, cnt, lno;
690         int result_deleted = 0;
691         char *result, *cp;
692         struct sline *sline; /* survived lines */
693         int mode_differs = 0;
694         int i, show_hunks;
695         int working_tree_file = is_null_sha1(elem->sha1);
696         int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
697         const char *a_prefix, *b_prefix;
698         mmfile_t result_file;
700         context = opt->context;
701         a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
702         b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
704         /* Read the result of merge first */
705         if (!working_tree_file)
706                 result = grab_blob(elem->sha1, elem->mode, &result_size);
707         else {
708                 /* Used by diff-tree to read from the working tree */
709                 struct stat st;
710                 int fd = -1;
712                 if (lstat(elem->path, &st) < 0)
713                         goto deleted_file;
715                 if (S_ISLNK(st.st_mode)) {
716                         struct strbuf buf = STRBUF_INIT;
718                         if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
719                                 error("readlink(%s): %s", elem->path,
720                                       strerror(errno));
721                                 return;
722                         }
723                         result_size = buf.len;
724                         result = strbuf_detach(&buf, NULL);
725                         elem->mode = canon_mode(st.st_mode);
726                 } else if (S_ISDIR(st.st_mode)) {
727                         unsigned char sha1[20];
728                         if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
729                                 result = grab_blob(elem->sha1, elem->mode, &result_size);
730                         else
731                                 result = grab_blob(sha1, elem->mode, &result_size);
732                 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
733                         size_t len = xsize_t(st.st_size);
734                         ssize_t done;
735                         int is_file, i;
737                         elem->mode = canon_mode(st.st_mode);
738                         /* if symlinks don't work, assume symlink if all parents
739                          * are symlinks
740                          */
741                         is_file = has_symlinks;
742                         for (i = 0; !is_file && i < num_parent; i++)
743                                 is_file = !S_ISLNK(elem->parent[i].mode);
744                         if (!is_file)
745                                 elem->mode = canon_mode(S_IFLNK);
747                         result_size = len;
748                         result = xmalloc(len + 1);
750                         done = read_in_full(fd, result, len);
751                         if (done < 0)
752                                 die_errno("read error '%s'", elem->path);
753                         else if (done < len)
754                                 die("early EOF '%s'", elem->path);
756                         result[len] = 0;
758                         /* If not a fake symlink, apply filters, e.g. autocrlf */
759                         if (is_file) {
760                                 struct strbuf buf = STRBUF_INIT;
762                                 if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
763                                         free(result);
764                                         result = strbuf_detach(&buf, &len);
765                                         result_size = len;
766                                 }
767                         }
768                 }
769                 else {
770                 deleted_file:
771                         result_deleted = 1;
772                         result_size = 0;
773                         elem->mode = 0;
774                         result = xcalloc(1, 1);
775                 }
777                 if (0 <= fd)
778                         close(fd);
779         }
781         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
782                 if (*cp == '\n')
783                         cnt++;
784         }
785         if (result_size && result[result_size-1] != '\n')
786                 cnt++; /* incomplete line */
788         sline = xcalloc(cnt+2, sizeof(*sline));
789         sline[0].bol = result;
790         for (lno = 0; lno <= cnt + 1; lno++) {
791                 sline[lno].lost_tail = &sline[lno].lost_head;
792                 sline[lno].flag = 0;
793         }
794         for (lno = 0, cp = result; cp < result + result_size; cp++) {
795                 if (*cp == '\n') {
796                         sline[lno].len = cp - sline[lno].bol;
797                         lno++;
798                         if (lno < cnt)
799                                 sline[lno].bol = cp + 1;
800                 }
801         }
802         if (result_size && result[result_size-1] != '\n')
803                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
805         result_file.ptr = result;
806         result_file.size = result_size;
808         /* Even p_lno[cnt+1] is valid -- that is for the end line number
809          * for deletion hunk at the end.
810          */
811         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
812         for (lno = 0; lno <= cnt; lno++)
813                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
815         for (i = 0; i < num_parent; i++) {
816                 int j;
817                 for (j = 0; j < i; j++) {
818                         if (!hashcmp(elem->parent[i].sha1,
819                                      elem->parent[j].sha1)) {
820                                 reuse_combine_diff(sline, cnt, i, j);
821                                 break;
822                         }
823                 }
824                 if (i <= j)
825                         combine_diff(elem->parent[i].sha1,
826                                      elem->parent[i].mode,
827                                      &result_file, sline,
828                                      cnt, i, num_parent, result_deleted);
829                 if (elem->parent[i].mode != elem->mode)
830                         mode_differs = 1;
831         }
833         show_hunks = make_hunks(sline, cnt, num_parent, dense);
835         if (show_hunks || mode_differs || working_tree_file) {
836                 const char *abb;
837                 int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
838                 const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
839                 const char *c_reset = diff_get_color(use_color, DIFF_RESET);
840                 int added = 0;
841                 int deleted = 0;
843                 if (rev->loginfo && !rev->no_commit_id)
844                         show_log(rev);
845                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
846                                  "", elem->path, c_meta, c_reset);
847                 printf("%sindex ", c_meta);
848                 for (i = 0; i < num_parent; i++) {
849                         abb = find_unique_abbrev(elem->parent[i].sha1,
850                                                  abbrev);
851                         printf("%s%s", i ? "," : "", abb);
852                 }
853                 abb = find_unique_abbrev(elem->sha1, abbrev);
854                 printf("..%s%s\n", abb, c_reset);
856                 if (mode_differs) {
857                         deleted = !elem->mode;
859                         /* We say it was added if nobody had it */
860                         added = !deleted;
861                         for (i = 0; added && i < num_parent; i++)
862                                 if (elem->parent[i].status !=
863                                     DIFF_STATUS_ADDED)
864                                         added = 0;
865                         if (added)
866                                 printf("%snew file mode %06o",
867                                        c_meta, elem->mode);
868                         else {
869                                 if (deleted)
870                                         printf("%sdeleted file ", c_meta);
871                                 printf("mode ");
872                                 for (i = 0; i < num_parent; i++) {
873                                         printf("%s%06o", i ? "," : "",
874                                                elem->parent[i].mode);
875                                 }
876                                 if (elem->mode)
877                                         printf("..%06o", elem->mode);
878                         }
879                         printf("%s\n", c_reset);
880                 }
881                 if (added)
882                         dump_quoted_path("--- ", "", "/dev/null",
883                                          c_meta, c_reset);
884                 else
885                         dump_quoted_path("--- ", a_prefix, elem->path,
886                                          c_meta, c_reset);
887                 if (deleted)
888                         dump_quoted_path("+++ ", "", "/dev/null",
889                                          c_meta, c_reset);
890                 else
891                         dump_quoted_path("+++ ", b_prefix, elem->path,
892                                          c_meta, c_reset);
893                 dump_sline(sline, cnt, num_parent,
894                            DIFF_OPT_TST(opt, COLOR_DIFF), result_deleted);
895         }
896         free(result);
898         for (lno = 0; lno < cnt; lno++) {
899                 if (sline[lno].lost_head) {
900                         struct lline *ll = sline[lno].lost_head;
901                         while (ll) {
902                                 struct lline *tmp = ll;
903                                 ll = ll->next;
904                                 free(tmp);
905                         }
906                 }
907         }
908         free(sline[0].p_lno);
909         free(sline);
912 #define COLONS "::::::::::::::::::::::::::::::::"
914 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
916         struct diff_options *opt = &rev->diffopt;
917         int i, offset;
918         const char *prefix;
919         int line_termination, inter_name_termination;
921         line_termination = opt->line_termination;
922         inter_name_termination = '\t';
923         if (!line_termination)
924                 inter_name_termination = 0;
926         if (rev->loginfo && !rev->no_commit_id)
927                 show_log(rev);
929         if (opt->output_format & DIFF_FORMAT_RAW) {
930                 offset = strlen(COLONS) - num_parent;
931                 if (offset < 0)
932                         offset = 0;
933                 prefix = COLONS + offset;
935                 /* Show the modes */
936                 for (i = 0; i < num_parent; i++) {
937                         printf("%s%06o", prefix, p->parent[i].mode);
938                         prefix = " ";
939                 }
940                 printf("%s%06o", prefix, p->mode);
942                 /* Show sha1's */
943                 for (i = 0; i < num_parent; i++)
944                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
945                                                          opt->abbrev));
946                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
947         }
949         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
950                 for (i = 0; i < num_parent; i++)
951                         putchar(p->parent[i].status);
952                 putchar(inter_name_termination);
953         }
955         write_name_quoted(p->path, stdout, line_termination);
958 void show_combined_diff(struct combine_diff_path *p,
959                        int num_parent,
960                        int dense,
961                        struct rev_info *rev)
963         struct diff_options *opt = &rev->diffopt;
964         if (!p->len)
965                 return;
966         if (opt->output_format & (DIFF_FORMAT_RAW |
967                                   DIFF_FORMAT_NAME |
968                                   DIFF_FORMAT_NAME_STATUS))
969                 show_raw_diff(p, num_parent, rev);
970         else if (opt->output_format & DIFF_FORMAT_PATCH)
971                 show_patch_diff(p, num_parent, dense, rev);
974 void diff_tree_combined(const unsigned char *sha1,
975                         const unsigned char parent[][20],
976                         int num_parent,
977                         int dense,
978                         struct rev_info *rev)
980         struct diff_options *opt = &rev->diffopt;
981         struct diff_options diffopts;
982         struct combine_diff_path *p, *paths = NULL;
983         int i, num_paths, needsep, show_log_first;
985         diffopts = *opt;
986         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
987         DIFF_OPT_SET(&diffopts, RECURSIVE);
988         DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
990         show_log_first = !!rev->loginfo && !rev->no_commit_id;
991         needsep = 0;
992         /* find set of paths that everybody touches */
993         for (i = 0; i < num_parent; i++) {
994                 /* show stat against the first parent even
995                  * when doing combined diff.
996                  */
997                 int stat_opt = (opt->output_format &
998                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
999                 if (i == 0 && stat_opt)
1000                         diffopts.output_format = stat_opt;
1001                 else
1002                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1003                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
1004                 diffcore_std(&diffopts);
1005                 paths = intersect_paths(paths, i, num_parent);
1007                 if (show_log_first && i == 0) {
1008                         show_log(rev);
1009                         if (rev->verbose_header && opt->output_format)
1010                                 putchar(opt->line_termination);
1011                 }
1012                 diff_flush(&diffopts);
1013         }
1015         /* find out surviving paths */
1016         for (num_paths = 0, p = paths; p; p = p->next) {
1017                 if (p->len)
1018                         num_paths++;
1019         }
1020         if (num_paths) {
1021                 if (opt->output_format & (DIFF_FORMAT_RAW |
1022                                           DIFF_FORMAT_NAME |
1023                                           DIFF_FORMAT_NAME_STATUS)) {
1024                         for (p = paths; p; p = p->next) {
1025                                 if (p->len)
1026                                         show_raw_diff(p, num_parent, rev);
1027                         }
1028                         needsep = 1;
1029                 }
1030                 else if (opt->output_format &
1031                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1032                         needsep = 1;
1033                 if (opt->output_format & DIFF_FORMAT_PATCH) {
1034                         if (needsep)
1035                                 putchar(opt->line_termination);
1036                         for (p = paths; p; p = p->next) {
1037                                 if (p->len)
1038                                         show_patch_diff(p, num_parent, dense,
1039                                                         rev);
1040                         }
1041                 }
1042         }
1044         /* Clean things up */
1045         while (paths) {
1046                 struct combine_diff_path *tmp = paths;
1047                 paths = paths->next;
1048                 free(tmp);
1049         }
1052 void diff_tree_combined_merge(const unsigned char *sha1,
1053                              int dense, struct rev_info *rev)
1055         int num_parent;
1056         const unsigned char (*parent)[20];
1057         struct commit *commit = lookup_commit(sha1);
1058         struct commit_list *parents;
1060         /* count parents */
1061         for (parents = commit->parents, num_parent = 0;
1062              parents;
1063              parents = parents->next, num_parent++)
1064                 ; /* nothing */
1066         parent = xmalloc(num_parent * sizeof(*parent));
1067         for (parents = commit->parents, num_parent = 0;
1068              parents;
1069              parents = parents->next, num_parent++)
1070                 hashcpy((unsigned char *)(parent + num_parent),
1071                         parents->item->object.sha1);
1072         diff_tree_combined(sha1, parent, num_parent, dense, rev);