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git-svn: Add --localtime option to "fetch"
[git.git] / merge-recursive.c
blobb97026bd5cc1d2ef1b46a9ef3dcd7562ad52c377
1 /*
2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
3 * Fredrik Kuivinen.
4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5 */
6 #include "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "string-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "attr.h"
20 #include "merge-recursive.h"
21 #include "dir.h"
22
23 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
24 {
25 unsigned char shifted[20];
26
27 /*
28 * NEEDSWORK: this limits the recursion depth to hardcoded
29 * value '2' to avoid excessive overhead.
30 */
31 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
32 if (!hashcmp(two->object.sha1, shifted))
33 return two;
34 return lookup_tree(shifted);
35 }
36
37 /*
38 * A virtual commit has (const char *)commit->util set to the name.
39 */
40
41 struct commit *make_virtual_commit(struct tree *tree, const char *comment)
42 {
43 struct commit *commit = xcalloc(1, sizeof(struct commit));
44 commit->tree = tree;
45 commit->util = (void*)comment;
46 /* avoid warnings */
47 commit->object.parsed = 1;
48 return commit;
49 }
50
51 /*
52 * Since we use get_tree_entry(), which does not put the read object into
53 * the object pool, we cannot rely on a == b.
54 */
55 static int sha_eq(const unsigned char *a, const unsigned char *b)
56 {
57 if (!a && !b)
58 return 2;
59 return a && b && hashcmp(a, b) == 0;
60 }
61
62 /*
63 * Since we want to write the index eventually, we cannot reuse the index
64 * for these (temporary) data.
65 */
66 struct stage_data
67 {
68 struct
69 {
70 unsigned mode;
71 unsigned char sha[20];
72 } stages[4];
73 unsigned processed:1;
74 };
75
76 static int show(struct merge_options *o, int v)
77 {
78 return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
79 }
80
81 static void flush_output(struct merge_options *o)
82 {
83 if (o->obuf.len) {
84 fputs(o->obuf.buf, stdout);
85 strbuf_reset(&o->obuf);
86 }
87 }
88
89 static void output(struct merge_options *o, int v, const char *fmt, ...)
90 {
91 int len;
92 va_list ap;
93
94 if (!show(o, v))
95 return;
96
97 strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
98 memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
99 strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
100
101 va_start(ap, fmt);
102 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
103 va_end(ap);
104
105 if (len < 0)
106 len = 0;
107 if (len >= strbuf_avail(&o->obuf)) {
108 strbuf_grow(&o->obuf, len + 2);
109 va_start(ap, fmt);
110 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
111 va_end(ap);
112 if (len >= strbuf_avail(&o->obuf)) {
113 die("this should not happen, your snprintf is broken");
114 }
115 }
116 strbuf_setlen(&o->obuf, o->obuf.len + len);
117 strbuf_add(&o->obuf, "\n", 1);
118 if (!o->buffer_output)
119 flush_output(o);
120 }
121
122 static void output_commit_title(struct merge_options *o, struct commit *commit)
123 {
124 int i;
125 flush_output(o);
126 for (i = o->call_depth; i--;)
127 fputs(" ", stdout);
128 if (commit->util)
129 printf("virtual %s\n", (char *)commit->util);
130 else {
131 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
132 if (parse_commit(commit) != 0)
133 printf("(bad commit)\n");
134 else {
135 const char *s;
136 int len;
137 for (s = commit->buffer; *s; s++)
138 if (*s == '\n' && s[1] == '\n') {
139 s += 2;
140 break;
141 }
142 for (len = 0; s[len] && '\n' != s[len]; len++)
143 ; /* do nothing */
144 printf("%.*s\n", len, s);
145 }
146 }
147 }
148
149 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
150 const char *path, int stage, int refresh, int options)
151 {
152 struct cache_entry *ce;
153 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
154 if (!ce)
155 return error("addinfo_cache failed for path '%s'", path);
156 return add_cache_entry(ce, options);
157 }
158
159 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
160 {
161 parse_tree(tree);
162 init_tree_desc(desc, tree->buffer, tree->size);
163 }
164
165 static int git_merge_trees(int index_only,
166 struct tree *common,
167 struct tree *head,
168 struct tree *merge)
169 {
170 int rc;
171 struct tree_desc t[3];
172 struct unpack_trees_options opts;
173
174 memset(&opts, 0, sizeof(opts));
175 if (index_only)
176 opts.index_only = 1;
177 else
178 opts.update = 1;
179 opts.merge = 1;
180 opts.head_idx = 2;
181 opts.fn = threeway_merge;
182 opts.src_index = &the_index;
183 opts.dst_index = &the_index;
184
185 init_tree_desc_from_tree(t+0, common);
186 init_tree_desc_from_tree(t+1, head);
187 init_tree_desc_from_tree(t+2, merge);
188
189 rc = unpack_trees(3, t, &opts);
190 cache_tree_free(&active_cache_tree);
191 return rc;
192 }
193
194 struct tree *write_tree_from_memory(struct merge_options *o)
195 {
196 struct tree *result = NULL;
197
198 if (unmerged_cache()) {
199 int i;
200 output(o, 0, "There are unmerged index entries:");
201 for (i = 0; i < active_nr; i++) {
202 struct cache_entry *ce = active_cache[i];
203 if (ce_stage(ce))
204 output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
205 }
206 return NULL;
207 }
208
209 if (!active_cache_tree)
210 active_cache_tree = cache_tree();
211
212 if (!cache_tree_fully_valid(active_cache_tree) &&
213 cache_tree_update(active_cache_tree,
214 active_cache, active_nr, 0, 0) < 0)
215 die("error building trees");
216
217 result = lookup_tree(active_cache_tree->sha1);
218
219 return result;
220 }
221
222 static int save_files_dirs(const unsigned char *sha1,
223 const char *base, int baselen, const char *path,
224 unsigned int mode, int stage, void *context)
225 {
226 int len = strlen(path);
227 char *newpath = xmalloc(baselen + len + 1);
228 struct merge_options *o = context;
229
230 memcpy(newpath, base, baselen);
231 memcpy(newpath + baselen, path, len);
232 newpath[baselen + len] = '\0';
233
234 if (S_ISDIR(mode))
235 string_list_insert(newpath, &o->current_directory_set);
236 else
237 string_list_insert(newpath, &o->current_file_set);
238 free(newpath);
239
240 return READ_TREE_RECURSIVE;
241 }
242
243 static int get_files_dirs(struct merge_options *o, struct tree *tree)
244 {
245 int n;
246 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
247 return 0;
248 n = o->current_file_set.nr + o->current_directory_set.nr;
249 return n;
250 }
251
252 /*
253 * Returns an index_entry instance which doesn't have to correspond to
254 * a real cache entry in Git's index.
255 */
256 static struct stage_data *insert_stage_data(const char *path,
257 struct tree *o, struct tree *a, struct tree *b,
258 struct string_list *entries)
259 {
260 struct string_list_item *item;
261 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
262 get_tree_entry(o->object.sha1, path,
263 e->stages[1].sha, &e->stages[1].mode);
264 get_tree_entry(a->object.sha1, path,
265 e->stages[2].sha, &e->stages[2].mode);
266 get_tree_entry(b->object.sha1, path,
267 e->stages[3].sha, &e->stages[3].mode);
268 item = string_list_insert(path, entries);
269 item->util = e;
270 return e;
271 }
272
273 /*
274 * Create a dictionary mapping file names to stage_data objects. The
275 * dictionary contains one entry for every path with a non-zero stage entry.
276 */
277 static struct string_list *get_unmerged(void)
278 {
279 struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
280 int i;
281
282 unmerged->strdup_strings = 1;
283
284 for (i = 0; i < active_nr; i++) {
285 struct string_list_item *item;
286 struct stage_data *e;
287 struct cache_entry *ce = active_cache[i];
288 if (!ce_stage(ce))
289 continue;
290
291 item = string_list_lookup(ce->name, unmerged);
292 if (!item) {
293 item = string_list_insert(ce->name, unmerged);
294 item->util = xcalloc(1, sizeof(struct stage_data));
295 }
296 e = item->util;
297 e->stages[ce_stage(ce)].mode = ce->ce_mode;
298 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
299 }
300
301 return unmerged;
302 }
303
304 struct rename
305 {
306 struct diff_filepair *pair;
307 struct stage_data *src_entry;
308 struct stage_data *dst_entry;
309 unsigned processed:1;
310 };
311
312 /*
313 * Get information of all renames which occurred between 'o_tree' and
314 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
315 * 'b_tree') to be able to associate the correct cache entries with
316 * the rename information. 'tree' is always equal to either a_tree or b_tree.
317 */
318 static struct string_list *get_renames(struct merge_options *o,
319 struct tree *tree,
320 struct tree *o_tree,
321 struct tree *a_tree,
322 struct tree *b_tree,
323 struct string_list *entries)
324 {
325 int i;
326 struct string_list *renames;
327 struct diff_options opts;
328
329 renames = xcalloc(1, sizeof(struct string_list));
330 diff_setup(&opts);
331 DIFF_OPT_SET(&opts, RECURSIVE);
332 opts.detect_rename = DIFF_DETECT_RENAME;
333 opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
334 o->diff_rename_limit >= 0 ? o->diff_rename_limit :
335 500;
336 opts.warn_on_too_large_rename = 1;
337 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
338 if (diff_setup_done(&opts) < 0)
339 die("diff setup failed");
340 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
341 diffcore_std(&opts);
342 for (i = 0; i < diff_queued_diff.nr; ++i) {
343 struct string_list_item *item;
344 struct rename *re;
345 struct diff_filepair *pair = diff_queued_diff.queue[i];
346 if (pair->status != 'R') {
347 diff_free_filepair(pair);
348 continue;
349 }
350 re = xmalloc(sizeof(*re));
351 re->processed = 0;
352 re->pair = pair;
353 item = string_list_lookup(re->pair->one->path, entries);
354 if (!item)
355 re->src_entry = insert_stage_data(re->pair->one->path,
356 o_tree, a_tree, b_tree, entries);
357 else
358 re->src_entry = item->util;
359
360 item = string_list_lookup(re->pair->two->path, entries);
361 if (!item)
362 re->dst_entry = insert_stage_data(re->pair->two->path,
363 o_tree, a_tree, b_tree, entries);
364 else
365 re->dst_entry = item->util;
366 item = string_list_insert(pair->one->path, renames);
367 item->util = re;
368 }
369 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
370 diff_queued_diff.nr = 0;
371 diff_flush(&opts);
372 return renames;
373 }
374
375 static int update_stages(const char *path, struct diff_filespec *o,
376 struct diff_filespec *a, struct diff_filespec *b,
377 int clear)
378 {
379 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
380 if (clear)
381 if (remove_file_from_cache(path))
382 return -1;
383 if (o)
384 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
385 return -1;
386 if (a)
387 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
388 return -1;
389 if (b)
390 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
391 return -1;
392 return 0;
393 }
394
395 static int remove_file(struct merge_options *o, int clean,
396 const char *path, int no_wd)
397 {
398 int update_cache = o->call_depth || clean;
399 int update_working_directory = !o->call_depth && !no_wd;
400
401 if (update_cache) {
402 if (remove_file_from_cache(path))
403 return -1;
404 }
405 if (update_working_directory) {
406 if (remove_path(path) && errno != ENOENT)
407 return -1;
408 }
409 return 0;
410 }
411
412 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
413 {
414 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
415 int suffix = 0;
416 struct stat st;
417 char *p = newpath + strlen(path);
418 strcpy(newpath, path);
419 *(p++) = '~';
420 strcpy(p, branch);
421 for (; *p; ++p)
422 if ('/' == *p)
423 *p = '_';
424 while (string_list_has_string(&o->current_file_set, newpath) ||
425 string_list_has_string(&o->current_directory_set, newpath) ||
426 lstat(newpath, &st) == 0)
427 sprintf(p, "_%d", suffix++);
428
429 string_list_insert(newpath, &o->current_file_set);
430 return newpath;
431 }
432
433 static void flush_buffer(int fd, const char *buf, unsigned long size)
434 {
435 while (size > 0) {
436 long ret = write_in_full(fd, buf, size);
437 if (ret < 0) {
438 /* Ignore epipe */
439 if (errno == EPIPE)
440 break;
441 die("merge-recursive: %s", strerror(errno));
442 } else if (!ret) {
443 die("merge-recursive: disk full?");
444 }
445 size -= ret;
446 buf += ret;
447 }
448 }
449
450 static int would_lose_untracked(const char *path)
451 {
452 int pos = cache_name_pos(path, strlen(path));
453
454 if (pos < 0)
455 pos = -1 - pos;
456 while (pos < active_nr &&
457 !strcmp(path, active_cache[pos]->name)) {
458 /*
459 * If stage #0, it is definitely tracked.
460 * If it has stage #2 then it was tracked
461 * before this merge started. All other
462 * cases the path was not tracked.
463 */
464 switch (ce_stage(active_cache[pos])) {
465 case 0:
466 case 2:
467 return 0;
468 }
469 pos++;
470 }
471 return file_exists(path);
472 }
473
474 static int make_room_for_path(const char *path)
475 {
476 int status;
477 const char *msg = "failed to create path '%s'%s";
478
479 status = safe_create_leading_directories_const(path);
480 if (status) {
481 if (status == -3) {
482 /* something else exists */
483 error(msg, path, ": perhaps a D/F conflict?");
484 return -1;
485 }
486 die(msg, path, "");
487 }
488
489 /*
490 * Do not unlink a file in the work tree if we are not
491 * tracking it.
492 */
493 if (would_lose_untracked(path))
494 return error("refusing to lose untracked file at '%s'",
495 path);
496
497 /* Successful unlink is good.. */
498 if (!unlink(path))
499 return 0;
500 /* .. and so is no existing file */
501 if (errno == ENOENT)
502 return 0;
503 /* .. but not some other error (who really cares what?) */
504 return error(msg, path, ": perhaps a D/F conflict?");
505 }
506
507 static void update_file_flags(struct merge_options *o,
508 const unsigned char *sha,
509 unsigned mode,
510 const char *path,
511 int update_cache,
512 int update_wd)
513 {
514 if (o->call_depth)
515 update_wd = 0;
516
517 if (update_wd) {
518 enum object_type type;
519 void *buf;
520 unsigned long size;
521
522 if (S_ISGITLINK(mode))
523 die("cannot read object %s '%s': It is a submodule!",
524 sha1_to_hex(sha), path);
525
526 buf = read_sha1_file(sha, &type, &size);
527 if (!buf)
528 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
529 if (type != OBJ_BLOB)
530 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
531 if (S_ISREG(mode)) {
532 struct strbuf strbuf = STRBUF_INIT;
533 if (convert_to_working_tree(path, buf, size, &strbuf)) {
534 free(buf);
535 size = strbuf.len;
536 buf = strbuf_detach(&strbuf, NULL);
537 }
538 }
539
540 if (make_room_for_path(path) < 0) {
541 update_wd = 0;
542 free(buf);
543 goto update_index;
544 }
545 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
546 int fd;
547 if (mode & 0100)
548 mode = 0777;
549 else
550 mode = 0666;
551 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
552 if (fd < 0)
553 die("failed to open %s: %s", path, strerror(errno));
554 flush_buffer(fd, buf, size);
555 close(fd);
556 } else if (S_ISLNK(mode)) {
557 char *lnk = xmemdupz(buf, size);
558 safe_create_leading_directories_const(path);
559 unlink(path);
560 if (symlink(lnk, path))
561 die("failed to symlink %s: %s", path, strerror(errno));
562 free(lnk);
563 } else
564 die("do not know what to do with %06o %s '%s'",
565 mode, sha1_to_hex(sha), path);
566 free(buf);
567 }
568 update_index:
569 if (update_cache)
570 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
571 }
572
573 static void update_file(struct merge_options *o,
574 int clean,
575 const unsigned char *sha,
576 unsigned mode,
577 const char *path)
578 {
579 update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
580 }
581
582 /* Low level file merging, update and removal */
583
584 struct merge_file_info
585 {
586 unsigned char sha[20];
587 unsigned mode;
588 unsigned clean:1,
589 merge:1;
590 };
591
592 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
593 {
594 unsigned long size;
595 enum object_type type;
596
597 if (!hashcmp(sha1, null_sha1)) {
598 mm->ptr = xstrdup("");
599 mm->size = 0;
600 return;
601 }
602
603 mm->ptr = read_sha1_file(sha1, &type, &size);
604 if (!mm->ptr || type != OBJ_BLOB)
605 die("unable to read blob object %s", sha1_to_hex(sha1));
606 mm->size = size;
607 }
608
609 static int merge_3way(struct merge_options *o,
610 mmbuffer_t *result_buf,
611 struct diff_filespec *one,
612 struct diff_filespec *a,
613 struct diff_filespec *b,
614 const char *branch1,
615 const char *branch2)
616 {
617 mmfile_t orig, src1, src2;
618 char *name1, *name2;
619 int merge_status;
620
621 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
622 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
623
624 fill_mm(one->sha1, &orig);
625 fill_mm(a->sha1, &src1);
626 fill_mm(b->sha1, &src2);
627
628 merge_status = ll_merge(result_buf, a->path, &orig,
629 &src1, name1, &src2, name2,
630 o->call_depth);
631
632 free(name1);
633 free(name2);
634 free(orig.ptr);
635 free(src1.ptr);
636 free(src2.ptr);
637 return merge_status;
638 }
639
640 static struct merge_file_info merge_file(struct merge_options *o,
641 struct diff_filespec *one,
642 struct diff_filespec *a,
643 struct diff_filespec *b,
644 const char *branch1,
645 const char *branch2)
646 {
647 struct merge_file_info result;
648 result.merge = 0;
649 result.clean = 1;
650
651 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
652 result.clean = 0;
653 if (S_ISREG(a->mode)) {
654 result.mode = a->mode;
655 hashcpy(result.sha, a->sha1);
656 } else {
657 result.mode = b->mode;
658 hashcpy(result.sha, b->sha1);
659 }
660 } else {
661 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
662 result.merge = 1;
663
664 /*
665 * Merge modes
666 */
667 if (a->mode == b->mode || a->mode == one->mode)
668 result.mode = b->mode;
669 else {
670 result.mode = a->mode;
671 if (b->mode != one->mode) {
672 result.clean = 0;
673 result.merge = 1;
674 }
675 }
676
677 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
678 hashcpy(result.sha, b->sha1);
679 else if (sha_eq(b->sha1, one->sha1))
680 hashcpy(result.sha, a->sha1);
681 else if (S_ISREG(a->mode)) {
682 mmbuffer_t result_buf;
683 int merge_status;
684
685 merge_status = merge_3way(o, &result_buf, one, a, b,
686 branch1, branch2);
687
688 if ((merge_status < 0) || !result_buf.ptr)
689 die("Failed to execute internal merge");
690
691 if (write_sha1_file(result_buf.ptr, result_buf.size,
692 blob_type, result.sha))
693 die("Unable to add %s to database",
694 a->path);
695
696 free(result_buf.ptr);
697 result.clean = (merge_status == 0);
698 } else if (S_ISGITLINK(a->mode)) {
699 result.clean = 0;
700 hashcpy(result.sha, a->sha1);
701 } else if (S_ISLNK(a->mode)) {
702 hashcpy(result.sha, a->sha1);
703
704 if (!sha_eq(a->sha1, b->sha1))
705 result.clean = 0;
706 } else {
707 die("unsupported object type in the tree");
708 }
709 }
710
711 return result;
712 }
713
714 static void conflict_rename_rename(struct merge_options *o,
715 struct rename *ren1,
716 const char *branch1,
717 struct rename *ren2,
718 const char *branch2)
719 {
720 char *del[2];
721 int delp = 0;
722 const char *ren1_dst = ren1->pair->two->path;
723 const char *ren2_dst = ren2->pair->two->path;
724 const char *dst_name1 = ren1_dst;
725 const char *dst_name2 = ren2_dst;
726 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
727 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
728 output(o, 1, "%s is a directory in %s adding as %s instead",
729 ren1_dst, branch2, dst_name1);
730 remove_file(o, 0, ren1_dst, 0);
731 }
732 if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
733 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
734 output(o, 1, "%s is a directory in %s adding as %s instead",
735 ren2_dst, branch1, dst_name2);
736 remove_file(o, 0, ren2_dst, 0);
737 }
738 if (o->call_depth) {
739 remove_file_from_cache(dst_name1);
740 remove_file_from_cache(dst_name2);
741 /*
742 * Uncomment to leave the conflicting names in the resulting tree
743 *
744 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
745 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
746 */
747 } else {
748 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
749 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
750 }
751 while (delp--)
752 free(del[delp]);
753 }
754
755 static void conflict_rename_dir(struct merge_options *o,
756 struct rename *ren1,
757 const char *branch1)
758 {
759 char *new_path = unique_path(o, ren1->pair->two->path, branch1);
760 output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
761 remove_file(o, 0, ren1->pair->two->path, 0);
762 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
763 free(new_path);
764 }
765
766 static void conflict_rename_rename_2(struct merge_options *o,
767 struct rename *ren1,
768 const char *branch1,
769 struct rename *ren2,
770 const char *branch2)
771 {
772 char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
773 char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
774 output(o, 1, "Renaming %s to %s and %s to %s instead",
775 ren1->pair->one->path, new_path1,
776 ren2->pair->one->path, new_path2);
777 remove_file(o, 0, ren1->pair->two->path, 0);
778 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
779 update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
780 free(new_path2);
781 free(new_path1);
782 }
783
784 static int process_renames(struct merge_options *o,
785 struct string_list *a_renames,
786 struct string_list *b_renames)
787 {
788 int clean_merge = 1, i, j;
789 struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
790 const struct rename *sre;
791
792 for (i = 0; i < a_renames->nr; i++) {
793 sre = a_renames->items[i].util;
794 string_list_insert(sre->pair->two->path, &a_by_dst)->util
795 = sre->dst_entry;
796 }
797 for (i = 0; i < b_renames->nr; i++) {
798 sre = b_renames->items[i].util;
799 string_list_insert(sre->pair->two->path, &b_by_dst)->util
800 = sre->dst_entry;
801 }
802
803 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
804 int compare;
805 char *src;
806 struct string_list *renames1, *renames2, *renames2Dst;
807 struct rename *ren1 = NULL, *ren2 = NULL;
808 const char *branch1, *branch2;
809 const char *ren1_src, *ren1_dst;
810
811 if (i >= a_renames->nr) {
812 compare = 1;
813 ren2 = b_renames->items[j++].util;
814 } else if (j >= b_renames->nr) {
815 compare = -1;
816 ren1 = a_renames->items[i++].util;
817 } else {
818 compare = strcmp(a_renames->items[i].string,
819 b_renames->items[j].string);
820 if (compare <= 0)
821 ren1 = a_renames->items[i++].util;
822 if (compare >= 0)
823 ren2 = b_renames->items[j++].util;
824 }
825
826 /* TODO: refactor, so that 1/2 are not needed */
827 if (ren1) {
828 renames1 = a_renames;
829 renames2 = b_renames;
830 renames2Dst = &b_by_dst;
831 branch1 = o->branch1;
832 branch2 = o->branch2;
833 } else {
834 struct rename *tmp;
835 renames1 = b_renames;
836 renames2 = a_renames;
837 renames2Dst = &a_by_dst;
838 branch1 = o->branch2;
839 branch2 = o->branch1;
840 tmp = ren2;
841 ren2 = ren1;
842 ren1 = tmp;
843 }
844 src = ren1->pair->one->path;
845
846 ren1->dst_entry->processed = 1;
847 ren1->src_entry->processed = 1;
848
849 if (ren1->processed)
850 continue;
851 ren1->processed = 1;
852
853 ren1_src = ren1->pair->one->path;
854 ren1_dst = ren1->pair->two->path;
855
856 if (ren2) {
857 const char *ren2_src = ren2->pair->one->path;
858 const char *ren2_dst = ren2->pair->two->path;
859 /* Renamed in 1 and renamed in 2 */
860 if (strcmp(ren1_src, ren2_src) != 0)
861 die("ren1.src != ren2.src");
862 ren2->dst_entry->processed = 1;
863 ren2->processed = 1;
864 if (strcmp(ren1_dst, ren2_dst) != 0) {
865 clean_merge = 0;
866 output(o, 1, "CONFLICT (rename/rename): "
867 "Rename \"%s\"->\"%s\" in branch \"%s\" "
868 "rename \"%s\"->\"%s\" in \"%s\"%s",
869 src, ren1_dst, branch1,
870 src, ren2_dst, branch2,
871 o->call_depth ? " (left unresolved)": "");
872 if (o->call_depth) {
873 remove_file_from_cache(src);
874 update_file(o, 0, ren1->pair->one->sha1,
875 ren1->pair->one->mode, src);
876 }
877 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
878 } else {
879 struct merge_file_info mfi;
880 remove_file(o, 1, ren1_src, 1);
881 mfi = merge_file(o,
882 ren1->pair->one,
883 ren1->pair->two,
884 ren2->pair->two,
885 branch1,
886 branch2);
887 if (mfi.merge || !mfi.clean)
888 output(o, 1, "Renaming %s->%s", src, ren1_dst);
889
890 if (mfi.merge)
891 output(o, 2, "Auto-merging %s", ren1_dst);
892
893 if (!mfi.clean) {
894 output(o, 1, "CONFLICT (content): merge conflict in %s",
895 ren1_dst);
896 clean_merge = 0;
897
898 if (!o->call_depth)
899 update_stages(ren1_dst,
900 ren1->pair->one,
901 ren1->pair->two,
902 ren2->pair->two,
903 1 /* clear */);
904 }
905 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
906 }
907 } else {
908 /* Renamed in 1, maybe changed in 2 */
909 struct string_list_item *item;
910 /* we only use sha1 and mode of these */
911 struct diff_filespec src_other, dst_other;
912 int try_merge, stage = a_renames == renames1 ? 3: 2;
913
914 remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
915
916 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
917 src_other.mode = ren1->src_entry->stages[stage].mode;
918 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
919 dst_other.mode = ren1->dst_entry->stages[stage].mode;
920
921 try_merge = 0;
922
923 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
924 clean_merge = 0;
925 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
926 " directory %s added in %s",
927 ren1_src, ren1_dst, branch1,
928 ren1_dst, branch2);
929 conflict_rename_dir(o, ren1, branch1);
930 } else if (sha_eq(src_other.sha1, null_sha1)) {
931 clean_merge = 0;
932 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
933 "and deleted in %s",
934 ren1_src, ren1_dst, branch1,
935 branch2);
936 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
937 update_stages(ren1_dst, NULL,
938 branch1 == o->branch1 ?
939 ren1->pair->two : NULL,
940 branch1 == o->branch1 ?
941 NULL : ren1->pair->two, 1);
942 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
943 const char *new_path;
944 clean_merge = 0;
945 try_merge = 1;
946 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
947 "%s added in %s",
948 ren1_src, ren1_dst, branch1,
949 ren1_dst, branch2);
950 new_path = unique_path(o, ren1_dst, branch2);
951 output(o, 1, "Adding as %s instead", new_path);
952 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
953 } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
954 ren2 = item->util;
955 clean_merge = 0;
956 ren2->processed = 1;
957 output(o, 1, "CONFLICT (rename/rename): "
958 "Rename %s->%s in %s. "
959 "Rename %s->%s in %s",
960 ren1_src, ren1_dst, branch1,
961 ren2->pair->one->path, ren2->pair->two->path, branch2);
962 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
963 } else
964 try_merge = 1;
965
966 if (try_merge) {
967 struct diff_filespec *one, *a, *b;
968 struct merge_file_info mfi;
969 src_other.path = (char *)ren1_src;
970
971 one = ren1->pair->one;
972 if (a_renames == renames1) {
973 a = ren1->pair->two;
974 b = &src_other;
975 } else {
976 b = ren1->pair->two;
977 a = &src_other;
978 }
979 mfi = merge_file(o, one, a, b,
980 o->branch1, o->branch2);
981
982 if (mfi.clean &&
983 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
984 mfi.mode == ren1->pair->two->mode)
985 /*
986 * This messaged is part of
987 * t6022 test. If you change
988 * it update the test too.
989 */
990 output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
991 else {
992 if (mfi.merge || !mfi.clean)
993 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
994 if (mfi.merge)
995 output(o, 2, "Auto-merging %s", ren1_dst);
996 if (!mfi.clean) {
997 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
998 ren1_dst);
999 clean_merge = 0;
1000
1001 if (!o->call_depth)
1002 update_stages(ren1_dst,
1003 one, a, b, 1);
1004 }
1005 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1006 }
1007 }
1008 }
1009 }
1010 string_list_clear(&a_by_dst, 0);
1011 string_list_clear(&b_by_dst, 0);
1012
1013 return clean_merge;
1014 }
1015
1016 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1017 {
1018 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1019 }
1020
1021 /* Per entry merge function */
1022 static int process_entry(struct merge_options *o,
1023 const char *path, struct stage_data *entry)
1024 {
1025 /*
1026 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1027 print_index_entry("\tpath: ", entry);
1028 */
1029 int clean_merge = 1;
1030 unsigned o_mode = entry->stages[1].mode;
1031 unsigned a_mode = entry->stages[2].mode;
1032 unsigned b_mode = entry->stages[3].mode;
1033 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1034 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1035 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1036
1037 if (o_sha && (!a_sha || !b_sha)) {
1038 /* Case A: Deleted in one */
1039 if ((!a_sha && !b_sha) ||
1040 (sha_eq(a_sha, o_sha) && !b_sha) ||
1041 (!a_sha && sha_eq(b_sha, o_sha))) {
1042 /* Deleted in both or deleted in one and
1043 * unchanged in the other */
1044 if (a_sha)
1045 output(o, 2, "Removing %s", path);
1046 /* do not touch working file if it did not exist */
1047 remove_file(o, 1, path, !a_sha);
1048 } else {
1049 /* Deleted in one and changed in the other */
1050 clean_merge = 0;
1051 if (!a_sha) {
1052 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1053 "and modified in %s. Version %s of %s left in tree.",
1054 path, o->branch1,
1055 o->branch2, o->branch2, path);
1056 update_file(o, 0, b_sha, b_mode, path);
1057 } else {
1058 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1059 "and modified in %s. Version %s of %s left in tree.",
1060 path, o->branch2,
1061 o->branch1, o->branch1, path);
1062 update_file(o, 0, a_sha, a_mode, path);
1063 }
1064 }
1065
1066 } else if ((!o_sha && a_sha && !b_sha) ||
1067 (!o_sha && !a_sha && b_sha)) {
1068 /* Case B: Added in one. */
1069 const char *add_branch;
1070 const char *other_branch;
1071 unsigned mode;
1072 const unsigned char *sha;
1073 const char *conf;
1074
1075 if (a_sha) {
1076 add_branch = o->branch1;
1077 other_branch = o->branch2;
1078 mode = a_mode;
1079 sha = a_sha;
1080 conf = "file/directory";
1081 } else {
1082 add_branch = o->branch2;
1083 other_branch = o->branch1;
1084 mode = b_mode;
1085 sha = b_sha;
1086 conf = "directory/file";
1087 }
1088 if (string_list_has_string(&o->current_directory_set, path)) {
1089 const char *new_path = unique_path(o, path, add_branch);
1090 clean_merge = 0;
1091 output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1092 "Adding %s as %s",
1093 conf, path, other_branch, path, new_path);
1094 remove_file(o, 0, path, 0);
1095 update_file(o, 0, sha, mode, new_path);
1096 } else {
1097 output(o, 2, "Adding %s", path);
1098 update_file(o, 1, sha, mode, path);
1099 }
1100 } else if (a_sha && b_sha) {
1101 /* Case C: Added in both (check for same permissions) and */
1102 /* case D: Modified in both, but differently. */
1103 const char *reason = "content";
1104 struct merge_file_info mfi;
1105 struct diff_filespec one, a, b;
1106
1107 if (!o_sha) {
1108 reason = "add/add";
1109 o_sha = (unsigned char *)null_sha1;
1110 }
1111 output(o, 2, "Auto-merging %s", path);
1112 one.path = a.path = b.path = (char *)path;
1113 hashcpy(one.sha1, o_sha);
1114 one.mode = o_mode;
1115 hashcpy(a.sha1, a_sha);
1116 a.mode = a_mode;
1117 hashcpy(b.sha1, b_sha);
1118 b.mode = b_mode;
1119
1120 mfi = merge_file(o, &one, &a, &b,
1121 o->branch1, o->branch2);
1122
1123 clean_merge = mfi.clean;
1124 if (mfi.clean)
1125 update_file(o, 1, mfi.sha, mfi.mode, path);
1126 else if (S_ISGITLINK(mfi.mode))
1127 output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
1128 "- needs %s", path, sha1_to_hex(b.sha1));
1129 else {
1130 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1131 reason, path);
1132
1133 if (o->call_depth)
1134 update_file(o, 0, mfi.sha, mfi.mode, path);
1135 else
1136 update_file_flags(o, mfi.sha, mfi.mode, path,
1137 0 /* update_cache */, 1 /* update_working_directory */);
1138 }
1139 } else if (!o_sha && !a_sha && !b_sha) {
1140 /*
1141 * this entry was deleted altogether. a_mode == 0 means
1142 * we had that path and want to actively remove it.
1143 */
1144 remove_file(o, 1, path, !a_mode);
1145 } else
1146 die("Fatal merge failure, shouldn't happen.");
1147
1148 return clean_merge;
1149 }
1150
1151 int merge_trees(struct merge_options *o,
1152 struct tree *head,
1153 struct tree *merge,
1154 struct tree *common,
1155 struct tree **result)
1156 {
1157 int code, clean;
1158
1159 if (o->subtree_merge) {
1160 merge = shift_tree_object(head, merge);
1161 common = shift_tree_object(head, common);
1162 }
1163
1164 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1165 output(o, 0, "Already uptodate!");
1166 *result = head;
1167 return 1;
1168 }
1169
1170 code = git_merge_trees(o->call_depth, common, head, merge);
1171
1172 if (code != 0)
1173 die("merging of trees %s and %s failed",
1174 sha1_to_hex(head->object.sha1),
1175 sha1_to_hex(merge->object.sha1));
1176
1177 if (unmerged_cache()) {
1178 struct string_list *entries, *re_head, *re_merge;
1179 int i;
1180 string_list_clear(&o->current_file_set, 1);
1181 string_list_clear(&o->current_directory_set, 1);
1182 get_files_dirs(o, head);
1183 get_files_dirs(o, merge);
1184
1185 entries = get_unmerged();
1186 re_head = get_renames(o, head, common, head, merge, entries);
1187 re_merge = get_renames(o, merge, common, head, merge, entries);
1188 clean = process_renames(o, re_head, re_merge);
1189 for (i = 0; i < entries->nr; i++) {
1190 const char *path = entries->items[i].string;
1191 struct stage_data *e = entries->items[i].util;
1192 if (!e->processed
1193 && !process_entry(o, path, e))
1194 clean = 0;
1195 }
1196
1197 string_list_clear(re_merge, 0);
1198 string_list_clear(re_head, 0);
1199 string_list_clear(entries, 1);
1200
1201 }
1202 else
1203 clean = 1;
1204
1205 if (o->call_depth)
1206 *result = write_tree_from_memory(o);
1207
1208 return clean;
1209 }
1210
1211 static struct commit_list *reverse_commit_list(struct commit_list *list)
1212 {
1213 struct commit_list *next = NULL, *current, *backup;
1214 for (current = list; current; current = backup) {
1215 backup = current->next;
1216 current->next = next;
1217 next = current;
1218 }
1219 return next;
1220 }
1221
1222 /*
1223 * Merge the commits h1 and h2, return the resulting virtual
1224 * commit object and a flag indicating the cleanness of the merge.
1225 */
1226 int merge_recursive(struct merge_options *o,
1227 struct commit *h1,
1228 struct commit *h2,
1229 struct commit_list *ca,
1230 struct commit **result)
1231 {
1232 struct commit_list *iter;
1233 struct commit *merged_common_ancestors;
1234 struct tree *mrtree = mrtree;
1235 int clean;
1236
1237 if (show(o, 4)) {
1238 output(o, 4, "Merging:");
1239 output_commit_title(o, h1);
1240 output_commit_title(o, h2);
1241 }
1242
1243 if (!ca) {
1244 ca = get_merge_bases(h1, h2, 1);
1245 ca = reverse_commit_list(ca);
1246 }
1247
1248 if (show(o, 5)) {
1249 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1250 for (iter = ca; iter; iter = iter->next)
1251 output_commit_title(o, iter->item);
1252 }
1253
1254 merged_common_ancestors = pop_commit(&ca);
1255 if (merged_common_ancestors == NULL) {
1256 /* if there is no common ancestor, make an empty tree */
1257 struct tree *tree = xcalloc(1, sizeof(struct tree));
1258
1259 tree->object.parsed = 1;
1260 tree->object.type = OBJ_TREE;
1261 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1262 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1263 }
1264
1265 for (iter = ca; iter; iter = iter->next) {
1266 const char *saved_b1, *saved_b2;
1267 o->call_depth++;
1268 /*
1269 * When the merge fails, the result contains files
1270 * with conflict markers. The cleanness flag is
1271 * ignored, it was never actually used, as result of
1272 * merge_trees has always overwritten it: the committed
1273 * "conflicts" were already resolved.
1274 */
1275 discard_cache();
1276 saved_b1 = o->branch1;
1277 saved_b2 = o->branch2;
1278 o->branch1 = "Temporary merge branch 1";
1279 o->branch2 = "Temporary merge branch 2";
1280 merge_recursive(o, merged_common_ancestors, iter->item,
1281 NULL, &merged_common_ancestors);
1282 o->branch1 = saved_b1;
1283 o->branch2 = saved_b2;
1284 o->call_depth--;
1285
1286 if (!merged_common_ancestors)
1287 die("merge returned no commit");
1288 }
1289
1290 discard_cache();
1291 if (!o->call_depth)
1292 read_cache();
1293
1294 clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1295 &mrtree);
1296
1297 if (o->call_depth) {
1298 *result = make_virtual_commit(mrtree, "merged tree");
1299 commit_list_insert(h1, &(*result)->parents);
1300 commit_list_insert(h2, &(*result)->parents->next);
1301 }
1302 flush_output(o);
1303 return clean;
1304 }
1305
1306 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1307 {
1308 struct object *object;
1309
1310 object = deref_tag(parse_object(sha1), name, strlen(name));
1311 if (!object)
1312 return NULL;
1313 if (object->type == OBJ_TREE)
1314 return make_virtual_commit((struct tree*)object, name);
1315 if (object->type != OBJ_COMMIT)
1316 return NULL;
1317 if (parse_commit((struct commit *)object))
1318 return NULL;
1319 return (struct commit *)object;
1320 }
1321
1322 int merge_recursive_generic(struct merge_options *o,
1323 const unsigned char *head,
1324 const unsigned char *merge,
1325 int num_base_list,
1326 const unsigned char **base_list,
1327 struct commit **result)
1328 {
1329 int clean, index_fd;
1330 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1331 struct commit *head_commit = get_ref(head, o->branch1);
1332 struct commit *next_commit = get_ref(merge, o->branch2);
1333 struct commit_list *ca = NULL;
1334
1335 if (base_list) {
1336 int i;
1337 for (i = 0; i < num_base_list; ++i) {
1338 struct commit *base;
1339 if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1340 return error("Could not parse object '%s'",
1341 sha1_to_hex(base_list[i]));
1342 commit_list_insert(base, &ca);
1343 }
1344 }
1345
1346 index_fd = hold_locked_index(lock, 1);
1347 clean = merge_recursive(o, head_commit, next_commit, ca,
1348 result);
1349 if (active_cache_changed &&
1350 (write_cache(index_fd, active_cache, active_nr) ||
1351 commit_locked_index(lock)))
1352 return error("Unable to write index.");
1353
1354 return clean ? 0 : 1;
1355 }
1356
1357 static int merge_recursive_config(const char *var, const char *value, void *cb)
1358 {
1359 struct merge_options *o = cb;
1360 if (!strcasecmp(var, "merge.verbosity")) {
1361 o->verbosity = git_config_int(var, value);
1362 return 0;
1363 }
1364 if (!strcasecmp(var, "diff.renamelimit")) {
1365 o->diff_rename_limit = git_config_int(var, value);
1366 return 0;
1367 }
1368 if (!strcasecmp(var, "merge.renamelimit")) {
1369 o->merge_rename_limit = git_config_int(var, value);
1370 return 0;
1371 }
1372 return git_xmerge_config(var, value, cb);
1373 }
1374
1375 void init_merge_options(struct merge_options *o)
1376 {
1377 memset(o, 0, sizeof(struct merge_options));
1378 o->verbosity = 2;
1379 o->buffer_output = 1;
1380 o->diff_rename_limit = -1;
1381 o->merge_rename_limit = -1;
1382 git_config(merge_recursive_config, o);
1383 if (getenv("GIT_MERGE_VERBOSITY"))
1384 o->verbosity =
1385 strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1386 if (o->verbosity >= 5)
1387 o->buffer_output = 0;
1388 strbuf_init(&o->obuf, 0);
1389 memset(&o->current_file_set, 0, sizeof(struct string_list));
1390 o->current_file_set.strdup_strings = 1;
1391 memset(&o->current_directory_set, 0, sizeof(struct string_list));
1392 o->current_directory_set.strdup_strings = 1;
1393 }
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