Merge branch 'jt/http-redact-cookies' into maint
[git.git] / combine-diff.c
blob2505de119a2be37e9dfb313a2e44db68595ad13f
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 "xdiff/xmacros.h"
9 #include "log-tree.h"
10 #include "refs.h"
11 #include "userdiff.h"
12 #include "sha1-array.h"
13 #include "revision.h"
15 static int compare_paths(const struct combine_diff_path *one,
16 const struct diff_filespec *two)
18 if (!S_ISDIR(one->mode) && !S_ISDIR(two->mode))
19 return strcmp(one->path, two->path);
21 return base_name_compare(one->path, strlen(one->path), one->mode,
22 two->path, strlen(two->path), two->mode);
25 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
27 struct diff_queue_struct *q = &diff_queued_diff;
28 struct combine_diff_path *p, **tail = &curr;
29 int i, cmp;
31 if (!n) {
32 for (i = 0; i < q->nr; i++) {
33 int len;
34 const char *path;
35 if (diff_unmodified_pair(q->queue[i]))
36 continue;
37 path = q->queue[i]->two->path;
38 len = strlen(path);
39 p = xmalloc(combine_diff_path_size(num_parent, len));
40 p->path = (char *) &(p->parent[num_parent]);
41 memcpy(p->path, path, len);
42 p->path[len] = 0;
43 p->next = NULL;
44 memset(p->parent, 0,
45 sizeof(p->parent[0]) * num_parent);
47 oidcpy(&p->oid, &q->queue[i]->two->oid);
48 p->mode = q->queue[i]->two->mode;
49 oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
50 p->parent[n].mode = q->queue[i]->one->mode;
51 p->parent[n].status = q->queue[i]->status;
52 *tail = p;
53 tail = &p->next;
55 return curr;
59 * paths in curr (linked list) and q->queue[] (array) are
60 * both sorted in the tree order.
62 i = 0;
63 while ((p = *tail) != NULL) {
64 cmp = ((i >= q->nr)
65 ? -1 : compare_paths(p, q->queue[i]->two));
67 if (cmp < 0) {
68 /* p->path not in q->queue[]; drop it */
69 *tail = p->next;
70 free(p);
71 continue;
74 if (cmp > 0) {
75 /* q->queue[i] not in p->path; skip it */
76 i++;
77 continue;
80 oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
81 p->parent[n].mode = q->queue[i]->one->mode;
82 p->parent[n].status = q->queue[i]->status;
84 tail = &p->next;
85 i++;
87 return curr;
90 /* Lines lost from parent */
91 struct lline {
92 struct lline *next, *prev;
93 int len;
94 unsigned long parent_map;
95 char line[FLEX_ARRAY];
98 /* Lines lost from current parent (before coalescing) */
99 struct plost {
100 struct lline *lost_head, *lost_tail;
101 int len;
104 /* Lines surviving in the merge result */
105 struct sline {
106 /* Accumulated and coalesced lost lines */
107 struct lline *lost;
108 int lenlost;
109 struct plost plost;
110 char *bol;
111 int len;
112 /* bit 0 up to (N-1) are on if the parent has this line (i.e.
113 * we did not change it).
114 * bit N is used for "interesting" lines, including context.
115 * bit (N+1) is used for "do not show deletion before this".
117 unsigned long flag;
118 unsigned long *p_lno;
121 static int match_string_spaces(const char *line1, int len1,
122 const char *line2, int len2,
123 long flags)
125 if (flags & XDF_WHITESPACE_FLAGS) {
126 for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
127 for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
130 if (!(flags & (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)))
131 return (len1 == len2 && !memcmp(line1, line2, len1));
133 while (len1 > 0 && len2 > 0) {
134 len1--;
135 len2--;
136 if (XDL_ISSPACE(line1[len1]) || XDL_ISSPACE(line2[len2])) {
137 if ((flags & XDF_IGNORE_WHITESPACE_CHANGE) &&
138 (!XDL_ISSPACE(line1[len1]) || !XDL_ISSPACE(line2[len2])))
139 return 0;
141 for (; len1 > 0 && XDL_ISSPACE(line1[len1]); len1--);
142 for (; len2 > 0 && XDL_ISSPACE(line2[len2]); len2--);
144 if (line1[len1] != line2[len2])
145 return 0;
148 if (flags & XDF_IGNORE_WHITESPACE) {
149 /* Consume remaining spaces */
150 for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
151 for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
154 /* We matched full line1 and line2 */
155 if (!len1 && !len2)
156 return 1;
158 return 0;
161 enum coalesce_direction { MATCH, BASE, NEW };
163 /* Coalesce new lines into base by finding LCS */
164 static struct lline *coalesce_lines(struct lline *base, int *lenbase,
165 struct lline *new, int lennew,
166 unsigned long parent, long flags)
168 int **lcs;
169 enum coalesce_direction **directions;
170 struct lline *baseend, *newend = NULL;
171 int i, j, origbaselen = *lenbase;
173 if (new == NULL)
174 return base;
176 if (base == NULL) {
177 *lenbase = lennew;
178 return new;
182 * Coalesce new lines into base by finding the LCS
183 * - Create the table to run dynamic programming
184 * - Compute the LCS
185 * - Then reverse read the direction structure:
186 * - If we have MATCH, assign parent to base flag, and consume
187 * both baseend and newend
188 * - Else if we have BASE, consume baseend
189 * - Else if we have NEW, insert newend lline into base and
190 * consume newend
192 lcs = xcalloc(st_add(origbaselen, 1), sizeof(int*));
193 directions = xcalloc(st_add(origbaselen, 1), sizeof(enum coalesce_direction*));
194 for (i = 0; i < origbaselen + 1; i++) {
195 lcs[i] = xcalloc(st_add(lennew, 1), sizeof(int));
196 directions[i] = xcalloc(st_add(lennew, 1), sizeof(enum coalesce_direction));
197 directions[i][0] = BASE;
199 for (j = 1; j < lennew + 1; j++)
200 directions[0][j] = NEW;
202 for (i = 1, baseend = base; i < origbaselen + 1; i++) {
203 for (j = 1, newend = new; j < lennew + 1; j++) {
204 if (match_string_spaces(baseend->line, baseend->len,
205 newend->line, newend->len, flags)) {
206 lcs[i][j] = lcs[i - 1][j - 1] + 1;
207 directions[i][j] = MATCH;
208 } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
209 lcs[i][j] = lcs[i][j - 1];
210 directions[i][j] = NEW;
211 } else {
212 lcs[i][j] = lcs[i - 1][j];
213 directions[i][j] = BASE;
215 if (newend->next)
216 newend = newend->next;
218 if (baseend->next)
219 baseend = baseend->next;
222 for (i = 0; i < origbaselen + 1; i++)
223 free(lcs[i]);
224 free(lcs);
226 /* At this point, baseend and newend point to the end of each lists */
227 i--;
228 j--;
229 while (i != 0 || j != 0) {
230 if (directions[i][j] == MATCH) {
231 baseend->parent_map |= 1<<parent;
232 baseend = baseend->prev;
233 newend = newend->prev;
234 i--;
235 j--;
236 } else if (directions[i][j] == NEW) {
237 struct lline *lline;
239 lline = newend;
240 /* Remove lline from new list and update newend */
241 if (lline->prev)
242 lline->prev->next = lline->next;
243 else
244 new = lline->next;
245 if (lline->next)
246 lline->next->prev = lline->prev;
248 newend = lline->prev;
249 j--;
251 /* Add lline to base list */
252 if (baseend) {
253 lline->next = baseend->next;
254 lline->prev = baseend;
255 if (lline->prev)
256 lline->prev->next = lline;
258 else {
259 lline->next = base;
260 base = lline;
262 (*lenbase)++;
264 if (lline->next)
265 lline->next->prev = lline;
267 } else {
268 baseend = baseend->prev;
269 i--;
273 newend = new;
274 while (newend) {
275 struct lline *lline = newend;
276 newend = newend->next;
277 free(lline);
280 for (i = 0; i < origbaselen + 1; i++)
281 free(directions[i]);
282 free(directions);
284 return base;
287 static char *grab_blob(const struct object_id *oid, unsigned int mode,
288 unsigned long *size, struct userdiff_driver *textconv,
289 const char *path)
291 char *blob;
292 enum object_type type;
294 if (S_ISGITLINK(mode)) {
295 struct strbuf buf = STRBUF_INIT;
296 strbuf_addf(&buf, "Subproject commit %s\n", oid_to_hex(oid));
297 *size = buf.len;
298 blob = strbuf_detach(&buf, NULL);
299 } else if (is_null_oid(oid)) {
300 /* deleted blob */
301 *size = 0;
302 return xcalloc(1, 1);
303 } else if (textconv) {
304 struct diff_filespec *df = alloc_filespec(path);
305 fill_filespec(df, oid, 1, mode);
306 *size = fill_textconv(textconv, df, &blob);
307 free_filespec(df);
308 } else {
309 blob = read_sha1_file(oid->hash, &type, size);
310 if (type != OBJ_BLOB)
311 die("object '%s' is not a blob!", oid_to_hex(oid));
313 return blob;
316 static void append_lost(struct sline *sline, int n, const char *line, int len)
318 struct lline *lline;
319 unsigned long this_mask = (1UL<<n);
320 if (line[len-1] == '\n')
321 len--;
323 FLEX_ALLOC_MEM(lline, line, line, len);
324 lline->len = len;
325 lline->next = NULL;
326 lline->prev = sline->plost.lost_tail;
327 if (lline->prev)
328 lline->prev->next = lline;
329 else
330 sline->plost.lost_head = lline;
331 sline->plost.lost_tail = lline;
332 sline->plost.len++;
333 lline->parent_map = this_mask;
336 struct combine_diff_state {
337 unsigned int lno;
338 int ob, on, nb, nn;
339 unsigned long nmask;
340 int num_parent;
341 int n;
342 struct sline *sline;
343 struct sline *lost_bucket;
346 static void consume_line(void *state_, char *line, unsigned long len)
348 struct combine_diff_state *state = state_;
349 if (5 < len && !memcmp("@@ -", line, 4)) {
350 if (parse_hunk_header(line, len,
351 &state->ob, &state->on,
352 &state->nb, &state->nn))
353 return;
354 state->lno = state->nb;
355 if (state->nn == 0) {
356 /* @@ -X,Y +N,0 @@ removed Y lines
357 * that would have come *after* line N
358 * in the result. Our lost buckets hang
359 * to the line after the removed lines,
361 * Note that this is correct even when N == 0,
362 * in which case the hunk removes the first
363 * line in the file.
365 state->lost_bucket = &state->sline[state->nb];
366 if (!state->nb)
367 state->nb = 1;
368 } else {
369 state->lost_bucket = &state->sline[state->nb-1];
371 if (!state->sline[state->nb-1].p_lno)
372 state->sline[state->nb-1].p_lno =
373 xcalloc(state->num_parent,
374 sizeof(unsigned long));
375 state->sline[state->nb-1].p_lno[state->n] = state->ob;
376 return;
378 if (!state->lost_bucket)
379 return; /* not in any hunk yet */
380 switch (line[0]) {
381 case '-':
382 append_lost(state->lost_bucket, state->n, line+1, len-1);
383 break;
384 case '+':
385 state->sline[state->lno-1].flag |= state->nmask;
386 state->lno++;
387 break;
391 static void combine_diff(const struct object_id *parent, unsigned int mode,
392 mmfile_t *result_file,
393 struct sline *sline, unsigned int cnt, int n,
394 int num_parent, int result_deleted,
395 struct userdiff_driver *textconv,
396 const char *path, long flags)
398 unsigned int p_lno, lno;
399 unsigned long nmask = (1UL << n);
400 xpparam_t xpp;
401 xdemitconf_t xecfg;
402 mmfile_t parent_file;
403 struct combine_diff_state state;
404 unsigned long sz;
406 if (result_deleted)
407 return; /* result deleted */
409 parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
410 parent_file.size = sz;
411 memset(&xpp, 0, sizeof(xpp));
412 xpp.flags = flags;
413 memset(&xecfg, 0, sizeof(xecfg));
414 memset(&state, 0, sizeof(state));
415 state.nmask = nmask;
416 state.sline = sline;
417 state.lno = 1;
418 state.num_parent = num_parent;
419 state.n = n;
421 if (xdi_diff_outf(&parent_file, result_file, consume_line, &state,
422 &xpp, &xecfg))
423 die("unable to generate combined diff for %s",
424 oid_to_hex(parent));
425 free(parent_file.ptr);
427 /* Assign line numbers for this parent.
429 * sline[lno].p_lno[n] records the first line number
430 * (counting from 1) for parent N if the final hunk display
431 * started by showing sline[lno] (possibly showing the lost
432 * lines attached to it first).
434 for (lno = 0, p_lno = 1; lno <= cnt; lno++) {
435 struct lline *ll;
436 sline[lno].p_lno[n] = p_lno;
438 /* Coalesce new lines */
439 if (sline[lno].plost.lost_head) {
440 struct sline *sl = &sline[lno];
441 sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
442 sl->plost.lost_head,
443 sl->plost.len, n, flags);
444 sl->plost.lost_head = sl->plost.lost_tail = NULL;
445 sl->plost.len = 0;
448 /* How many lines would this sline advance the p_lno? */
449 ll = sline[lno].lost;
450 while (ll) {
451 if (ll->parent_map & nmask)
452 p_lno++; /* '-' means parent had it */
453 ll = ll->next;
455 if (lno < cnt && !(sline[lno].flag & nmask))
456 p_lno++; /* no '+' means parent had it */
458 sline[lno].p_lno[n] = p_lno; /* trailer */
461 static unsigned long context = 3;
462 static char combine_marker = '@';
464 static int interesting(struct sline *sline, unsigned long all_mask)
466 /* If some parents lost lines here, or if we have added to
467 * some parent, it is interesting.
469 return ((sline->flag & all_mask) || sline->lost);
472 static unsigned long adjust_hunk_tail(struct sline *sline,
473 unsigned long all_mask,
474 unsigned long hunk_begin,
475 unsigned long i)
477 /* i points at the first uninteresting line. If the last line
478 * of the hunk was interesting only because it has some
479 * deletion, then it is not all that interesting for the
480 * purpose of giving trailing context lines. This is because
481 * we output '-' line and then unmodified sline[i-1] itself in
482 * that case which gives us one extra context line.
484 if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
485 i--;
486 return i;
489 static unsigned long find_next(struct sline *sline,
490 unsigned long mark,
491 unsigned long i,
492 unsigned long cnt,
493 int look_for_uninteresting)
495 /* We have examined up to i-1 and are about to look at i.
496 * Find next interesting or uninteresting line. Here,
497 * "interesting" does not mean interesting(), but marked by
498 * the give_context() function below (i.e. it includes context
499 * lines that are not interesting to interesting() function
500 * that are surrounded by interesting() ones.
502 while (i <= cnt)
503 if (look_for_uninteresting
504 ? !(sline[i].flag & mark)
505 : (sline[i].flag & mark))
506 return i;
507 else
508 i++;
509 return i;
512 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
514 unsigned long all_mask = (1UL<<num_parent) - 1;
515 unsigned long mark = (1UL<<num_parent);
516 unsigned long no_pre_delete = (2UL<<num_parent);
517 unsigned long i;
519 /* Two groups of interesting lines may have a short gap of
520 * uninteresting lines. Connect such groups to give them a
521 * bit of context.
523 * We first start from what the interesting() function says,
524 * and mark them with "mark", and paint context lines with the
525 * mark. So interesting() would still say false for such context
526 * lines but they are treated as "interesting" in the end.
528 i = find_next(sline, mark, 0, cnt, 0);
529 if (cnt < i)
530 return 0;
532 while (i <= cnt) {
533 unsigned long j = (context < i) ? (i - context) : 0;
534 unsigned long k;
536 /* Paint a few lines before the first interesting line. */
537 while (j < i) {
538 if (!(sline[j].flag & mark))
539 sline[j].flag |= no_pre_delete;
540 sline[j++].flag |= mark;
543 again:
544 /* we know up to i is to be included. where does the
545 * next uninteresting one start?
547 j = find_next(sline, mark, i, cnt, 1);
548 if (cnt < j)
549 break; /* the rest are all interesting */
551 /* lookahead context lines */
552 k = find_next(sline, mark, j, cnt, 0);
553 j = adjust_hunk_tail(sline, all_mask, i, j);
555 if (k < j + context) {
556 /* k is interesting and [j,k) are not, but
557 * paint them interesting because the gap is small.
559 while (j < k)
560 sline[j++].flag |= mark;
561 i = k;
562 goto again;
565 /* j is the first uninteresting line and there is
566 * no overlap beyond it within context lines. Paint
567 * the trailing edge a bit.
569 i = k;
570 k = (j + context < cnt+1) ? j + context : cnt+1;
571 while (j < k)
572 sline[j++].flag |= mark;
574 return 1;
577 static int make_hunks(struct sline *sline, unsigned long cnt,
578 int num_parent, int dense)
580 unsigned long all_mask = (1UL<<num_parent) - 1;
581 unsigned long mark = (1UL<<num_parent);
582 unsigned long i;
583 int has_interesting = 0;
585 for (i = 0; i <= cnt; i++) {
586 if (interesting(&sline[i], all_mask))
587 sline[i].flag |= mark;
588 else
589 sline[i].flag &= ~mark;
591 if (!dense)
592 return give_context(sline, cnt, num_parent);
594 /* Look at each hunk, and if we have changes from only one
595 * parent, or the changes are the same from all but one
596 * parent, mark that uninteresting.
598 i = 0;
599 while (i <= cnt) {
600 unsigned long j, hunk_begin, hunk_end;
601 unsigned long same_diff;
602 while (i <= cnt && !(sline[i].flag & mark))
603 i++;
604 if (cnt < i)
605 break; /* No more interesting hunks */
606 hunk_begin = i;
607 for (j = i + 1; j <= cnt; j++) {
608 if (!(sline[j].flag & mark)) {
609 /* Look beyond the end to see if there
610 * is an interesting line after this
611 * hunk within context span.
613 unsigned long la; /* lookahead */
614 int contin = 0;
615 la = adjust_hunk_tail(sline, all_mask,
616 hunk_begin, j);
617 la = (la + context < cnt + 1) ?
618 (la + context) : cnt + 1;
619 while (la && j <= --la) {
620 if (sline[la].flag & mark) {
621 contin = 1;
622 break;
625 if (!contin)
626 break;
627 j = la;
630 hunk_end = j;
632 /* [i..hunk_end) are interesting. Now is it really
633 * interesting? We check if there are only two versions
634 * and the result matches one of them. That is, we look
635 * at:
636 * (+) line, which records lines added to which parents;
637 * this line appears in the result.
638 * (-) line, which records from what parents the line
639 * was removed; this line does not appear in the result.
640 * then check the set of parents the result has difference
641 * from, from all lines. If there are lines that has
642 * different set of parents that the result has differences
643 * from, that means we have more than two versions.
645 * Even when we have only two versions, if the result does
646 * not match any of the parents, the it should be considered
647 * interesting. In such a case, we would have all '+' line.
648 * After passing the above "two versions" test, that would
649 * appear as "the same set of parents" to be "all parents".
651 same_diff = 0;
652 has_interesting = 0;
653 for (j = i; j < hunk_end && !has_interesting; j++) {
654 unsigned long this_diff = sline[j].flag & all_mask;
655 struct lline *ll = sline[j].lost;
656 if (this_diff) {
657 /* This has some changes. Is it the
658 * same as others?
660 if (!same_diff)
661 same_diff = this_diff;
662 else if (same_diff != this_diff) {
663 has_interesting = 1;
664 break;
667 while (ll && !has_interesting) {
668 /* Lost this line from these parents;
669 * who are they? Are they the same?
671 this_diff = ll->parent_map;
672 if (!same_diff)
673 same_diff = this_diff;
674 else if (same_diff != this_diff) {
675 has_interesting = 1;
677 ll = ll->next;
681 if (!has_interesting && same_diff != all_mask) {
682 /* This hunk is not that interesting after all */
683 for (j = hunk_begin; j < hunk_end; j++)
684 sline[j].flag &= ~mark;
686 i = hunk_end;
689 has_interesting = give_context(sline, cnt, num_parent);
690 return has_interesting;
693 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
695 l0 = sline[l0].p_lno[n];
696 l1 = sline[l1].p_lno[n];
697 printf(" -%lu,%lu", l0, l1-l0-null_context);
700 static int hunk_comment_line(const char *bol)
702 int ch;
704 if (!bol)
705 return 0;
706 ch = *bol & 0xff;
707 return (isalpha(ch) || ch == '_' || ch == '$');
710 static void show_line_to_eol(const char *line, int len, const char *reset)
712 int saw_cr_at_eol = 0;
713 if (len < 0)
714 len = strlen(line);
715 saw_cr_at_eol = (len && line[len-1] == '\r');
717 printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
718 reset,
719 saw_cr_at_eol ? "\r" : "");
722 static void dump_sline(struct sline *sline, const char *line_prefix,
723 unsigned long cnt, int num_parent,
724 int use_color, int result_deleted)
726 unsigned long mark = (1UL<<num_parent);
727 unsigned long no_pre_delete = (2UL<<num_parent);
728 int i;
729 unsigned long lno = 0;
730 const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
731 const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
732 const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
733 const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
734 const char *c_context = diff_get_color(use_color, DIFF_CONTEXT);
735 const char *c_reset = diff_get_color(use_color, DIFF_RESET);
737 if (result_deleted)
738 return; /* result deleted */
740 while (1) {
741 unsigned long hunk_end;
742 unsigned long rlines;
743 const char *hunk_comment = NULL;
744 unsigned long null_context = 0;
746 while (lno <= cnt && !(sline[lno].flag & mark)) {
747 if (hunk_comment_line(sline[lno].bol))
748 hunk_comment = sline[lno].bol;
749 lno++;
751 if (cnt < lno)
752 break;
753 else {
754 for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
755 if (!(sline[hunk_end].flag & mark))
756 break;
758 rlines = hunk_end - lno;
759 if (cnt < hunk_end)
760 rlines--; /* pointing at the last delete hunk */
762 if (!context) {
764 * Even when running with --unified=0, all
765 * lines in the hunk needs to be processed in
766 * the loop below in order to show the
767 * deletion recorded in lost_head. However,
768 * we do not want to show the resulting line
769 * with all blank context markers in such a
770 * case. Compensate.
772 unsigned long j;
773 for (j = lno; j < hunk_end; j++)
774 if (!(sline[j].flag & (mark-1)))
775 null_context++;
776 rlines -= null_context;
779 printf("%s%s", line_prefix, c_frag);
780 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
781 for (i = 0; i < num_parent; i++)
782 show_parent_lno(sline, lno, hunk_end, i, null_context);
783 printf(" +%lu,%lu ", lno+1, rlines);
784 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
786 if (hunk_comment) {
787 int comment_end = 0;
788 for (i = 0; i < 40; i++) {
789 int ch = hunk_comment[i] & 0xff;
790 if (!ch || ch == '\n')
791 break;
792 if (!isspace(ch))
793 comment_end = i;
795 if (comment_end)
796 printf("%s%s %s%s", c_reset,
797 c_context, c_reset,
798 c_func);
799 for (i = 0; i < comment_end; i++)
800 putchar(hunk_comment[i]);
803 printf("%s\n", c_reset);
804 while (lno < hunk_end) {
805 struct lline *ll;
806 int j;
807 unsigned long p_mask;
808 struct sline *sl = &sline[lno++];
809 ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
810 while (ll) {
811 printf("%s%s", line_prefix, c_old);
812 for (j = 0; j < num_parent; j++) {
813 if (ll->parent_map & (1UL<<j))
814 putchar('-');
815 else
816 putchar(' ');
818 show_line_to_eol(ll->line, -1, c_reset);
819 ll = ll->next;
821 if (cnt < lno)
822 break;
823 p_mask = 1;
824 fputs(line_prefix, stdout);
825 if (!(sl->flag & (mark-1))) {
827 * This sline was here to hang the
828 * lost lines in front of it.
830 if (!context)
831 continue;
832 fputs(c_context, stdout);
834 else
835 fputs(c_new, stdout);
836 for (j = 0; j < num_parent; j++) {
837 if (p_mask & sl->flag)
838 putchar('+');
839 else
840 putchar(' ');
841 p_mask <<= 1;
843 show_line_to_eol(sl->bol, sl->len, c_reset);
848 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
849 int i, int j)
851 /* We have already examined parent j and we know parent i
852 * and parent j are the same, so reuse the combined result
853 * of parent j for parent i.
855 unsigned long lno, imask, jmask;
856 imask = (1UL<<i);
857 jmask = (1UL<<j);
859 for (lno = 0; lno <= cnt; lno++) {
860 struct lline *ll = sline->lost;
861 sline->p_lno[i] = sline->p_lno[j];
862 while (ll) {
863 if (ll->parent_map & jmask)
864 ll->parent_map |= imask;
865 ll = ll->next;
867 if (sline->flag & jmask)
868 sline->flag |= imask;
869 sline++;
871 /* the overall size of the file (sline[cnt]) */
872 sline->p_lno[i] = sline->p_lno[j];
875 static void dump_quoted_path(const char *head,
876 const char *prefix,
877 const char *path,
878 const char *line_prefix,
879 const char *c_meta, const char *c_reset)
881 static struct strbuf buf = STRBUF_INIT;
883 strbuf_reset(&buf);
884 strbuf_addstr(&buf, line_prefix);
885 strbuf_addstr(&buf, c_meta);
886 strbuf_addstr(&buf, head);
887 quote_two_c_style(&buf, prefix, path, 0);
888 strbuf_addstr(&buf, c_reset);
889 puts(buf.buf);
892 static void show_combined_header(struct combine_diff_path *elem,
893 int num_parent,
894 int dense,
895 struct rev_info *rev,
896 const char *line_prefix,
897 int mode_differs,
898 int show_file_header)
900 struct diff_options *opt = &rev->diffopt;
901 int abbrev = opt->flags.full_index ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
902 const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
903 const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
904 const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
905 const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
906 const char *abb;
907 int added = 0;
908 int deleted = 0;
909 int i;
911 if (rev->loginfo && !rev->no_commit_id)
912 show_log(rev);
914 dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
915 "", elem->path, line_prefix, c_meta, c_reset);
916 printf("%s%sindex ", line_prefix, c_meta);
917 for (i = 0; i < num_parent; i++) {
918 abb = find_unique_abbrev(elem->parent[i].oid.hash,
919 abbrev);
920 printf("%s%s", i ? "," : "", abb);
922 abb = find_unique_abbrev(elem->oid.hash, abbrev);
923 printf("..%s%s\n", abb, c_reset);
925 if (mode_differs) {
926 deleted = !elem->mode;
928 /* We say it was added if nobody had it */
929 added = !deleted;
930 for (i = 0; added && i < num_parent; i++)
931 if (elem->parent[i].status !=
932 DIFF_STATUS_ADDED)
933 added = 0;
934 if (added)
935 printf("%s%snew file mode %06o",
936 line_prefix, c_meta, elem->mode);
937 else {
938 if (deleted)
939 printf("%s%sdeleted file ",
940 line_prefix, c_meta);
941 printf("mode ");
942 for (i = 0; i < num_parent; i++) {
943 printf("%s%06o", i ? "," : "",
944 elem->parent[i].mode);
946 if (elem->mode)
947 printf("..%06o", elem->mode);
949 printf("%s\n", c_reset);
952 if (!show_file_header)
953 return;
955 if (added)
956 dump_quoted_path("--- ", "", "/dev/null",
957 line_prefix, c_meta, c_reset);
958 else
959 dump_quoted_path("--- ", a_prefix, elem->path,
960 line_prefix, c_meta, c_reset);
961 if (deleted)
962 dump_quoted_path("+++ ", "", "/dev/null",
963 line_prefix, c_meta, c_reset);
964 else
965 dump_quoted_path("+++ ", b_prefix, elem->path,
966 line_prefix, c_meta, c_reset);
969 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
970 int dense, int working_tree_file,
971 struct rev_info *rev)
973 struct diff_options *opt = &rev->diffopt;
974 unsigned long result_size, cnt, lno;
975 int result_deleted = 0;
976 char *result, *cp;
977 struct sline *sline; /* survived lines */
978 int mode_differs = 0;
979 int i, show_hunks;
980 mmfile_t result_file;
981 struct userdiff_driver *userdiff;
982 struct userdiff_driver *textconv = NULL;
983 int is_binary;
984 const char *line_prefix = diff_line_prefix(opt);
986 context = opt->context;
987 userdiff = userdiff_find_by_path(elem->path);
988 if (!userdiff)
989 userdiff = userdiff_find_by_name("default");
990 if (opt->flags.allow_textconv)
991 textconv = userdiff_get_textconv(userdiff);
993 /* Read the result of merge first */
994 if (!working_tree_file)
995 result = grab_blob(&elem->oid, elem->mode, &result_size,
996 textconv, elem->path);
997 else {
998 /* Used by diff-tree to read from the working tree */
999 struct stat st;
1000 int fd = -1;
1002 if (lstat(elem->path, &st) < 0)
1003 goto deleted_file;
1005 if (S_ISLNK(st.st_mode)) {
1006 struct strbuf buf = STRBUF_INIT;
1008 if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
1009 error_errno("readlink(%s)", elem->path);
1010 return;
1012 result_size = buf.len;
1013 result = strbuf_detach(&buf, NULL);
1014 elem->mode = canon_mode(st.st_mode);
1015 } else if (S_ISDIR(st.st_mode)) {
1016 struct object_id oid;
1017 if (resolve_gitlink_ref(elem->path, "HEAD", &oid) < 0)
1018 result = grab_blob(&elem->oid, elem->mode,
1019 &result_size, NULL, NULL);
1020 else
1021 result = grab_blob(&oid, elem->mode,
1022 &result_size, NULL, NULL);
1023 } else if (textconv) {
1024 struct diff_filespec *df = alloc_filespec(elem->path);
1025 fill_filespec(df, &null_oid, 0, st.st_mode);
1026 result_size = fill_textconv(textconv, df, &result);
1027 free_filespec(df);
1028 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
1029 size_t len = xsize_t(st.st_size);
1030 ssize_t done;
1031 int is_file, i;
1033 elem->mode = canon_mode(st.st_mode);
1034 /* if symlinks don't work, assume symlink if all parents
1035 * are symlinks
1037 is_file = has_symlinks;
1038 for (i = 0; !is_file && i < num_parent; i++)
1039 is_file = !S_ISLNK(elem->parent[i].mode);
1040 if (!is_file)
1041 elem->mode = canon_mode(S_IFLNK);
1043 result_size = len;
1044 result = xmallocz(len);
1046 done = read_in_full(fd, result, len);
1047 if (done < 0)
1048 die_errno("read error '%s'", elem->path);
1049 else if (done < len)
1050 die("early EOF '%s'", elem->path);
1052 /* If not a fake symlink, apply filters, e.g. autocrlf */
1053 if (is_file) {
1054 struct strbuf buf = STRBUF_INIT;
1056 if (convert_to_git(&the_index, elem->path, result, len, &buf, safe_crlf)) {
1057 free(result);
1058 result = strbuf_detach(&buf, &len);
1059 result_size = len;
1063 else {
1064 deleted_file:
1065 result_deleted = 1;
1066 result_size = 0;
1067 elem->mode = 0;
1068 result = xcalloc(1, 1);
1071 if (0 <= fd)
1072 close(fd);
1075 for (i = 0; i < num_parent; i++) {
1076 if (elem->parent[i].mode != elem->mode) {
1077 mode_differs = 1;
1078 break;
1082 if (textconv)
1083 is_binary = 0;
1084 else if (userdiff->binary != -1)
1085 is_binary = userdiff->binary;
1086 else {
1087 is_binary = buffer_is_binary(result, result_size);
1088 for (i = 0; !is_binary && i < num_parent; i++) {
1089 char *buf;
1090 unsigned long size;
1091 buf = grab_blob(&elem->parent[i].oid,
1092 elem->parent[i].mode,
1093 &size, NULL, NULL);
1094 if (buffer_is_binary(buf, size))
1095 is_binary = 1;
1096 free(buf);
1099 if (is_binary) {
1100 show_combined_header(elem, num_parent, dense, rev,
1101 line_prefix, mode_differs, 0);
1102 printf("Binary files differ\n");
1103 free(result);
1104 return;
1107 for (cnt = 0, cp = result; cp < result + result_size; cp++) {
1108 if (*cp == '\n')
1109 cnt++;
1111 if (result_size && result[result_size-1] != '\n')
1112 cnt++; /* incomplete line */
1114 sline = xcalloc(st_add(cnt, 2), sizeof(*sline));
1115 sline[0].bol = result;
1116 for (lno = 0, cp = result; cp < result + result_size; cp++) {
1117 if (*cp == '\n') {
1118 sline[lno].len = cp - sline[lno].bol;
1119 lno++;
1120 if (lno < cnt)
1121 sline[lno].bol = cp + 1;
1124 if (result_size && result[result_size-1] != '\n')
1125 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
1127 result_file.ptr = result;
1128 result_file.size = result_size;
1130 /* Even p_lno[cnt+1] is valid -- that is for the end line number
1131 * for deletion hunk at the end.
1133 sline[0].p_lno = xcalloc(st_mult(st_add(cnt, 2), num_parent), sizeof(unsigned long));
1134 for (lno = 0; lno <= cnt; lno++)
1135 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
1137 for (i = 0; i < num_parent; i++) {
1138 int j;
1139 for (j = 0; j < i; j++) {
1140 if (!oidcmp(&elem->parent[i].oid,
1141 &elem->parent[j].oid)) {
1142 reuse_combine_diff(sline, cnt, i, j);
1143 break;
1146 if (i <= j)
1147 combine_diff(&elem->parent[i].oid,
1148 elem->parent[i].mode,
1149 &result_file, sline,
1150 cnt, i, num_parent, result_deleted,
1151 textconv, elem->path, opt->xdl_opts);
1154 show_hunks = make_hunks(sline, cnt, num_parent, dense);
1156 if (show_hunks || mode_differs || working_tree_file) {
1157 show_combined_header(elem, num_parent, dense, rev,
1158 line_prefix, mode_differs, 1);
1159 dump_sline(sline, line_prefix, cnt, num_parent,
1160 opt->use_color, result_deleted);
1162 free(result);
1164 for (lno = 0; lno < cnt; lno++) {
1165 if (sline[lno].lost) {
1166 struct lline *ll = sline[lno].lost;
1167 while (ll) {
1168 struct lline *tmp = ll;
1169 ll = ll->next;
1170 free(tmp);
1174 free(sline[0].p_lno);
1175 free(sline);
1178 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
1180 struct diff_options *opt = &rev->diffopt;
1181 int line_termination, inter_name_termination, i;
1182 const char *line_prefix = diff_line_prefix(opt);
1184 line_termination = opt->line_termination;
1185 inter_name_termination = '\t';
1186 if (!line_termination)
1187 inter_name_termination = 0;
1189 if (rev->loginfo && !rev->no_commit_id)
1190 show_log(rev);
1193 if (opt->output_format & DIFF_FORMAT_RAW) {
1194 printf("%s", line_prefix);
1196 /* As many colons as there are parents */
1197 for (i = 0; i < num_parent; i++)
1198 putchar(':');
1200 /* Show the modes */
1201 for (i = 0; i < num_parent; i++)
1202 printf("%06o ", p->parent[i].mode);
1203 printf("%06o", p->mode);
1205 /* Show sha1's */
1206 for (i = 0; i < num_parent; i++)
1207 printf(" %s", diff_aligned_abbrev(&p->parent[i].oid,
1208 opt->abbrev));
1209 printf(" %s ", diff_aligned_abbrev(&p->oid, opt->abbrev));
1212 if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1213 for (i = 0; i < num_parent; i++)
1214 putchar(p->parent[i].status);
1215 putchar(inter_name_termination);
1218 write_name_quoted(p->path, stdout, line_termination);
1222 * The result (p->elem) is from the working tree and their
1223 * parents are typically from multiple stages during a merge
1224 * (i.e. diff-files) or the state in HEAD and in the index
1225 * (i.e. diff-index).
1227 void show_combined_diff(struct combine_diff_path *p,
1228 int num_parent,
1229 int dense,
1230 struct rev_info *rev)
1232 struct diff_options *opt = &rev->diffopt;
1234 if (opt->output_format & (DIFF_FORMAT_RAW |
1235 DIFF_FORMAT_NAME |
1236 DIFF_FORMAT_NAME_STATUS))
1237 show_raw_diff(p, num_parent, rev);
1238 else if (opt->output_format & DIFF_FORMAT_PATCH)
1239 show_patch_diff(p, num_parent, dense, 1, rev);
1242 static void free_combined_pair(struct diff_filepair *pair)
1244 free(pair->two);
1245 free(pair);
1249 * A combine_diff_path expresses N parents on the LHS against 1 merge
1250 * result. Synthesize a diff_filepair that has N entries on the "one"
1251 * side and 1 entry on the "two" side.
1253 * In the future, we might want to add more data to combine_diff_path
1254 * so that we can fill fields we are ignoring (most notably, size) here,
1255 * but currently nobody uses it, so this should suffice for now.
1257 static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1258 int num_parent)
1260 int i;
1261 struct diff_filepair *pair;
1262 struct diff_filespec *pool;
1264 pair = xmalloc(sizeof(*pair));
1265 pool = xcalloc(st_add(num_parent, 1), sizeof(struct diff_filespec));
1266 pair->one = pool + 1;
1267 pair->two = pool;
1269 for (i = 0; i < num_parent; i++) {
1270 pair->one[i].path = p->path;
1271 pair->one[i].mode = p->parent[i].mode;
1272 oidcpy(&pair->one[i].oid, &p->parent[i].oid);
1273 pair->one[i].oid_valid = !is_null_oid(&p->parent[i].oid);
1274 pair->one[i].has_more_entries = 1;
1276 pair->one[num_parent - 1].has_more_entries = 0;
1278 pair->two->path = p->path;
1279 pair->two->mode = p->mode;
1280 oidcpy(&pair->two->oid, &p->oid);
1281 pair->two->oid_valid = !is_null_oid(&p->oid);
1282 return pair;
1285 static void handle_combined_callback(struct diff_options *opt,
1286 struct combine_diff_path *paths,
1287 int num_parent,
1288 int num_paths)
1290 struct combine_diff_path *p;
1291 struct diff_queue_struct q;
1292 int i;
1294 q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1295 q.alloc = num_paths;
1296 q.nr = num_paths;
1297 for (i = 0, p = paths; p; p = p->next)
1298 q.queue[i++] = combined_pair(p, num_parent);
1299 opt->format_callback(&q, opt, opt->format_callback_data);
1300 for (i = 0; i < num_paths; i++)
1301 free_combined_pair(q.queue[i]);
1302 free(q.queue);
1305 static const char *path_path(void *obj)
1307 struct combine_diff_path *path = (struct combine_diff_path *)obj;
1309 return path->path;
1313 /* find set of paths that every parent touches */
1314 static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
1315 const struct oid_array *parents, struct diff_options *opt)
1317 struct combine_diff_path *paths = NULL;
1318 int i, num_parent = parents->nr;
1320 int output_format = opt->output_format;
1321 const char *orderfile = opt->orderfile;
1323 opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1324 /* tell diff_tree to emit paths in sorted (=tree) order */
1325 opt->orderfile = NULL;
1327 /* D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (wrt paths) */
1328 for (i = 0; i < num_parent; i++) {
1330 * show stat against the first parent even when doing
1331 * combined diff.
1333 int stat_opt = (output_format &
1334 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1335 if (i == 0 && stat_opt)
1336 opt->output_format = stat_opt;
1337 else
1338 opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1339 diff_tree_oid(&parents->oid[i], oid, "", opt);
1340 diffcore_std(opt);
1341 paths = intersect_paths(paths, i, num_parent);
1343 /* if showing diff, show it in requested order */
1344 if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1345 orderfile) {
1346 diffcore_order(orderfile);
1349 diff_flush(opt);
1352 opt->output_format = output_format;
1353 opt->orderfile = orderfile;
1354 return paths;
1359 * find set of paths that everybody touches, assuming diff is run without
1360 * rename/copy detection, etc, comparing all trees simultaneously (= faster).
1362 static struct combine_diff_path *find_paths_multitree(
1363 const struct object_id *oid, const struct oid_array *parents,
1364 struct diff_options *opt)
1366 int i, nparent = parents->nr;
1367 const struct object_id **parents_oid;
1368 struct combine_diff_path paths_head;
1369 struct strbuf base;
1371 ALLOC_ARRAY(parents_oid, nparent);
1372 for (i = 0; i < nparent; i++)
1373 parents_oid[i] = &parents->oid[i];
1375 /* fake list head, so worker can assume it is non-NULL */
1376 paths_head.next = NULL;
1378 strbuf_init(&base, PATH_MAX);
1379 diff_tree_paths(&paths_head, oid, parents_oid, nparent, &base, opt);
1381 strbuf_release(&base);
1382 free(parents_oid);
1383 return paths_head.next;
1387 void diff_tree_combined(const struct object_id *oid,
1388 const struct oid_array *parents,
1389 int dense,
1390 struct rev_info *rev)
1392 struct diff_options *opt = &rev->diffopt;
1393 struct diff_options diffopts;
1394 struct combine_diff_path *p, *paths;
1395 int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
1396 int need_generic_pathscan;
1398 /* nothing to do, if no parents */
1399 if (!num_parent)
1400 return;
1402 show_log_first = !!rev->loginfo && !rev->no_commit_id;
1403 needsep = 0;
1404 if (show_log_first) {
1405 show_log(rev);
1407 if (rev->verbose_header && opt->output_format &&
1408 opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1409 !commit_format_is_empty(rev->commit_format))
1410 printf("%s%c", diff_line_prefix(opt),
1411 opt->line_termination);
1414 diffopts = *opt;
1415 copy_pathspec(&diffopts.pathspec, &opt->pathspec);
1416 diffopts.flags.recursive = 1;
1417 diffopts.flags.allow_external = 0;
1419 /* find set of paths that everybody touches
1421 * NOTE
1423 * Diffcore transformations are bound to diff_filespec and logic
1424 * comparing two entries - i.e. they do not apply directly to combine
1425 * diff.
1427 * If some of such transformations is requested - we launch generic
1428 * path scanning, which works significantly slower compared to
1429 * simultaneous all-trees-in-one-go scan in find_paths_multitree().
1431 * TODO some of the filters could be ported to work on
1432 * combine_diff_paths - i.e. all functionality that skips paths, so in
1433 * theory, we could end up having only multitree path scanning.
1435 * NOTE please keep this semantically in sync with diffcore_std()
1437 need_generic_pathscan = opt->skip_stat_unmatch ||
1438 opt->flags.follow_renames ||
1439 opt->break_opt != -1 ||
1440 opt->detect_rename ||
1441 opt->pickaxe ||
1442 opt->filter;
1445 if (need_generic_pathscan) {
1447 * NOTE generic case also handles --stat, as it computes
1448 * diff(sha1,parent_i) for all i to do the job, specifically
1449 * for parent0.
1451 paths = find_paths_generic(oid, parents, &diffopts);
1453 else {
1454 int stat_opt;
1455 paths = find_paths_multitree(oid, parents, &diffopts);
1458 * show stat against the first parent even
1459 * when doing combined diff.
1461 stat_opt = (opt->output_format &
1462 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1463 if (stat_opt) {
1464 diffopts.output_format = stat_opt;
1466 diff_tree_oid(&parents->oid[0], oid, "", &diffopts);
1467 diffcore_std(&diffopts);
1468 if (opt->orderfile)
1469 diffcore_order(opt->orderfile);
1470 diff_flush(&diffopts);
1474 /* find out number of surviving paths */
1475 for (num_paths = 0, p = paths; p; p = p->next)
1476 num_paths++;
1478 /* order paths according to diffcore_order */
1479 if (opt->orderfile && num_paths) {
1480 struct obj_order *o;
1482 ALLOC_ARRAY(o, num_paths);
1483 for (i = 0, p = paths; p; p = p->next, i++)
1484 o[i].obj = p;
1485 order_objects(opt->orderfile, path_path, o, num_paths);
1486 for (i = 0; i < num_paths - 1; i++) {
1487 p = o[i].obj;
1488 p->next = o[i+1].obj;
1491 p = o[num_paths-1].obj;
1492 p->next = NULL;
1493 paths = o[0].obj;
1494 free(o);
1498 if (num_paths) {
1499 if (opt->output_format & (DIFF_FORMAT_RAW |
1500 DIFF_FORMAT_NAME |
1501 DIFF_FORMAT_NAME_STATUS)) {
1502 for (p = paths; p; p = p->next)
1503 show_raw_diff(p, num_parent, rev);
1504 needsep = 1;
1506 else if (opt->output_format &
1507 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1508 needsep = 1;
1509 else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1510 handle_combined_callback(opt, paths, num_parent, num_paths);
1512 if (opt->output_format & DIFF_FORMAT_PATCH) {
1513 if (needsep)
1514 printf("%s%c", diff_line_prefix(opt),
1515 opt->line_termination);
1516 for (p = paths; p; p = p->next)
1517 show_patch_diff(p, num_parent, dense,
1518 0, rev);
1522 /* Clean things up */
1523 while (paths) {
1524 struct combine_diff_path *tmp = paths;
1525 paths = paths->next;
1526 free(tmp);
1529 clear_pathspec(&diffopts.pathspec);
1532 void diff_tree_combined_merge(const struct commit *commit, int dense,
1533 struct rev_info *rev)
1535 struct commit_list *parent = get_saved_parents(rev, commit);
1536 struct oid_array parents = OID_ARRAY_INIT;
1538 while (parent) {
1539 oid_array_append(&parents, &parent->item->object.oid);
1540 parent = parent->next;
1542 diff_tree_combined(&commit->object.oid, &parents, dense, rev);
1543 oid_array_clear(&parents);