Merge branch 'jc/better-conflict-resolution'
[git/git.git] / merge-recursive.c
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 "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.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_path(const char *name)
396 {
397 char *slash, *dirs;
398
399 if (unlink(name))
400 return -1;
401 dirs = xstrdup(name);
402 while ((slash = strrchr(name, '/'))) {
403 *slash = '\0';
404 if (rmdir(name) != 0)
405 break;
406 }
407 free(dirs);
408 return 0;
409 }
410
411 static int remove_file(struct merge_options *o, int clean,
412 const char *path, int no_wd)
413 {
414 int update_cache = o->call_depth || clean;
415 int update_working_directory = !o->call_depth && !no_wd;
416
417 if (update_cache) {
418 if (remove_file_from_cache(path))
419 return -1;
420 }
421 if (update_working_directory) {
422 if (remove_path(path) && errno != ENOENT)
423 return -1;
424 }
425 return 0;
426 }
427
428 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
429 {
430 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
431 int suffix = 0;
432 struct stat st;
433 char *p = newpath + strlen(path);
434 strcpy(newpath, path);
435 *(p++) = '~';
436 strcpy(p, branch);
437 for (; *p; ++p)
438 if ('/' == *p)
439 *p = '_';
440 while (string_list_has_string(&o->current_file_set, newpath) ||
441 string_list_has_string(&o->current_directory_set, newpath) ||
442 lstat(newpath, &st) == 0)
443 sprintf(p, "_%d", suffix++);
444
445 string_list_insert(newpath, &o->current_file_set);
446 return newpath;
447 }
448
449 static void flush_buffer(int fd, const char *buf, unsigned long size)
450 {
451 while (size > 0) {
452 long ret = write_in_full(fd, buf, size);
453 if (ret < 0) {
454 /* Ignore epipe */
455 if (errno == EPIPE)
456 break;
457 die("merge-recursive: %s", strerror(errno));
458 } else if (!ret) {
459 die("merge-recursive: disk full?");
460 }
461 size -= ret;
462 buf += ret;
463 }
464 }
465
466 static int make_room_for_path(const char *path)
467 {
468 int status;
469 const char *msg = "failed to create path '%s'%s";
470
471 status = safe_create_leading_directories_const(path);
472 if (status) {
473 if (status == -3) {
474 /* something else exists */
475 error(msg, path, ": perhaps a D/F conflict?");
476 return -1;
477 }
478 die(msg, path, "");
479 }
480
481 /* Successful unlink is good.. */
482 if (!unlink(path))
483 return 0;
484 /* .. and so is no existing file */
485 if (errno == ENOENT)
486 return 0;
487 /* .. but not some other error (who really cares what?) */
488 return error(msg, path, ": perhaps a D/F conflict?");
489 }
490
491 static void update_file_flags(struct merge_options *o,
492 const unsigned char *sha,
493 unsigned mode,
494 const char *path,
495 int update_cache,
496 int update_wd)
497 {
498 if (o->call_depth)
499 update_wd = 0;
500
501 if (update_wd) {
502 enum object_type type;
503 void *buf;
504 unsigned long size;
505
506 if (S_ISGITLINK(mode))
507 die("cannot read object %s '%s': It is a submodule!",
508 sha1_to_hex(sha), path);
509
510 buf = read_sha1_file(sha, &type, &size);
511 if (!buf)
512 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
513 if (type != OBJ_BLOB)
514 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
515 if (S_ISREG(mode)) {
516 struct strbuf strbuf;
517 strbuf_init(&strbuf, 0);
518 if (convert_to_working_tree(path, buf, size, &strbuf)) {
519 free(buf);
520 size = strbuf.len;
521 buf = strbuf_detach(&strbuf, NULL);
522 }
523 }
524
525 if (make_room_for_path(path) < 0) {
526 update_wd = 0;
527 free(buf);
528 goto update_index;
529 }
530 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
531 int fd;
532 if (mode & 0100)
533 mode = 0777;
534 else
535 mode = 0666;
536 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
537 if (fd < 0)
538 die("failed to open %s: %s", path, strerror(errno));
539 flush_buffer(fd, buf, size);
540 close(fd);
541 } else if (S_ISLNK(mode)) {
542 char *lnk = xmemdupz(buf, size);
543 safe_create_leading_directories_const(path);
544 unlink(path);
545 symlink(lnk, path);
546 free(lnk);
547 } else
548 die("do not know what to do with %06o %s '%s'",
549 mode, sha1_to_hex(sha), path);
550 free(buf);
551 }
552 update_index:
553 if (update_cache)
554 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
555 }
556
557 static void update_file(struct merge_options *o,
558 int clean,
559 const unsigned char *sha,
560 unsigned mode,
561 const char *path)
562 {
563 update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
564 }
565
566 /* Low level file merging, update and removal */
567
568 struct merge_file_info
569 {
570 unsigned char sha[20];
571 unsigned mode;
572 unsigned clean:1,
573 merge:1;
574 };
575
576 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
577 {
578 unsigned long size;
579 enum object_type type;
580
581 if (!hashcmp(sha1, null_sha1)) {
582 mm->ptr = xstrdup("");
583 mm->size = 0;
584 return;
585 }
586
587 mm->ptr = read_sha1_file(sha1, &type, &size);
588 if (!mm->ptr || type != OBJ_BLOB)
589 die("unable to read blob object %s", sha1_to_hex(sha1));
590 mm->size = size;
591 }
592
593 static int merge_3way(struct merge_options *o,
594 mmbuffer_t *result_buf,
595 struct diff_filespec *one,
596 struct diff_filespec *a,
597 struct diff_filespec *b,
598 const char *branch1,
599 const char *branch2)
600 {
601 mmfile_t orig, src1, src2;
602 char *name1, *name2;
603 int merge_status;
604
605 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
606 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
607
608 fill_mm(one->sha1, &orig);
609 fill_mm(a->sha1, &src1);
610 fill_mm(b->sha1, &src2);
611
612 merge_status = ll_merge(result_buf, a->path, &orig,
613 &src1, name1, &src2, name2,
614 o->call_depth);
615
616 free(name1);
617 free(name2);
618 free(orig.ptr);
619 free(src1.ptr);
620 free(src2.ptr);
621 return merge_status;
622 }
623
624 static struct merge_file_info merge_file(struct merge_options *o,
625 struct diff_filespec *one,
626 struct diff_filespec *a,
627 struct diff_filespec *b,
628 const char *branch1,
629 const char *branch2)
630 {
631 struct merge_file_info result;
632 result.merge = 0;
633 result.clean = 1;
634
635 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
636 result.clean = 0;
637 if (S_ISREG(a->mode)) {
638 result.mode = a->mode;
639 hashcpy(result.sha, a->sha1);
640 } else {
641 result.mode = b->mode;
642 hashcpy(result.sha, b->sha1);
643 }
644 } else {
645 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
646 result.merge = 1;
647
648 /*
649 * Merge modes
650 */
651 if (a->mode == b->mode || a->mode == one->mode)
652 result.mode = b->mode;
653 else {
654 result.mode = a->mode;
655 if (b->mode != one->mode) {
656 result.clean = 0;
657 result.merge = 1;
658 }
659 }
660
661 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
662 hashcpy(result.sha, b->sha1);
663 else if (sha_eq(b->sha1, one->sha1))
664 hashcpy(result.sha, a->sha1);
665 else if (S_ISREG(a->mode)) {
666 mmbuffer_t result_buf;
667 int merge_status;
668
669 merge_status = merge_3way(o, &result_buf, one, a, b,
670 branch1, branch2);
671
672 if ((merge_status < 0) || !result_buf.ptr)
673 die("Failed to execute internal merge");
674
675 if (write_sha1_file(result_buf.ptr, result_buf.size,
676 blob_type, result.sha))
677 die("Unable to add %s to database",
678 a->path);
679
680 free(result_buf.ptr);
681 result.clean = (merge_status == 0);
682 } else if (S_ISGITLINK(a->mode)) {
683 result.clean = 0;
684 hashcpy(result.sha, a->sha1);
685 } else if (S_ISLNK(a->mode)) {
686 hashcpy(result.sha, a->sha1);
687
688 if (!sha_eq(a->sha1, b->sha1))
689 result.clean = 0;
690 } else {
691 die("unsupported object type in the tree");
692 }
693 }
694
695 return result;
696 }
697
698 static void conflict_rename_rename(struct merge_options *o,
699 struct rename *ren1,
700 const char *branch1,
701 struct rename *ren2,
702 const char *branch2)
703 {
704 char *del[2];
705 int delp = 0;
706 const char *ren1_dst = ren1->pair->two->path;
707 const char *ren2_dst = ren2->pair->two->path;
708 const char *dst_name1 = ren1_dst;
709 const char *dst_name2 = ren2_dst;
710 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
711 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
712 output(o, 1, "%s is a directory in %s adding as %s instead",
713 ren1_dst, branch2, dst_name1);
714 remove_file(o, 0, ren1_dst, 0);
715 }
716 if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
717 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
718 output(o, 1, "%s is a directory in %s adding as %s instead",
719 ren2_dst, branch1, dst_name2);
720 remove_file(o, 0, ren2_dst, 0);
721 }
722 if (o->call_depth) {
723 remove_file_from_cache(dst_name1);
724 remove_file_from_cache(dst_name2);
725 /*
726 * Uncomment to leave the conflicting names in the resulting tree
727 *
728 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
729 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
730 */
731 } else {
732 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
733 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
734 }
735 while (delp--)
736 free(del[delp]);
737 }
738
739 static void conflict_rename_dir(struct merge_options *o,
740 struct rename *ren1,
741 const char *branch1)
742 {
743 char *new_path = unique_path(o, ren1->pair->two->path, branch1);
744 output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
745 remove_file(o, 0, ren1->pair->two->path, 0);
746 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
747 free(new_path);
748 }
749
750 static void conflict_rename_rename_2(struct merge_options *o,
751 struct rename *ren1,
752 const char *branch1,
753 struct rename *ren2,
754 const char *branch2)
755 {
756 char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
757 char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
758 output(o, 1, "Renaming %s to %s and %s to %s instead",
759 ren1->pair->one->path, new_path1,
760 ren2->pair->one->path, new_path2);
761 remove_file(o, 0, ren1->pair->two->path, 0);
762 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
763 update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
764 free(new_path2);
765 free(new_path1);
766 }
767
768 static int process_renames(struct merge_options *o,
769 struct string_list *a_renames,
770 struct string_list *b_renames)
771 {
772 int clean_merge = 1, i, j;
773 struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
774 const struct rename *sre;
775
776 for (i = 0; i < a_renames->nr; i++) {
777 sre = a_renames->items[i].util;
778 string_list_insert(sre->pair->two->path, &a_by_dst)->util
779 = sre->dst_entry;
780 }
781 for (i = 0; i < b_renames->nr; i++) {
782 sre = b_renames->items[i].util;
783 string_list_insert(sre->pair->two->path, &b_by_dst)->util
784 = sre->dst_entry;
785 }
786
787 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
788 int compare;
789 char *src;
790 struct string_list *renames1, *renames2, *renames2Dst;
791 struct rename *ren1 = NULL, *ren2 = NULL;
792 const char *branch1, *branch2;
793 const char *ren1_src, *ren1_dst;
794
795 if (i >= a_renames->nr) {
796 compare = 1;
797 ren2 = b_renames->items[j++].util;
798 } else if (j >= b_renames->nr) {
799 compare = -1;
800 ren1 = a_renames->items[i++].util;
801 } else {
802 compare = strcmp(a_renames->items[i].string,
803 b_renames->items[j].string);
804 if (compare <= 0)
805 ren1 = a_renames->items[i++].util;
806 if (compare >= 0)
807 ren2 = b_renames->items[j++].util;
808 }
809
810 /* TODO: refactor, so that 1/2 are not needed */
811 if (ren1) {
812 renames1 = a_renames;
813 renames2 = b_renames;
814 renames2Dst = &b_by_dst;
815 branch1 = o->branch1;
816 branch2 = o->branch2;
817 } else {
818 struct rename *tmp;
819 renames1 = b_renames;
820 renames2 = a_renames;
821 renames2Dst = &a_by_dst;
822 branch1 = o->branch2;
823 branch2 = o->branch1;
824 tmp = ren2;
825 ren2 = ren1;
826 ren1 = tmp;
827 }
828 src = ren1->pair->one->path;
829
830 ren1->dst_entry->processed = 1;
831 ren1->src_entry->processed = 1;
832
833 if (ren1->processed)
834 continue;
835 ren1->processed = 1;
836
837 ren1_src = ren1->pair->one->path;
838 ren1_dst = ren1->pair->two->path;
839
840 if (ren2) {
841 const char *ren2_src = ren2->pair->one->path;
842 const char *ren2_dst = ren2->pair->two->path;
843 /* Renamed in 1 and renamed in 2 */
844 if (strcmp(ren1_src, ren2_src) != 0)
845 die("ren1.src != ren2.src");
846 ren2->dst_entry->processed = 1;
847 ren2->processed = 1;
848 if (strcmp(ren1_dst, ren2_dst) != 0) {
849 clean_merge = 0;
850 output(o, 1, "CONFLICT (rename/rename): "
851 "Rename \"%s\"->\"%s\" in branch \"%s\" "
852 "rename \"%s\"->\"%s\" in \"%s\"%s",
853 src, ren1_dst, branch1,
854 src, ren2_dst, branch2,
855 o->call_depth ? " (left unresolved)": "");
856 if (o->call_depth) {
857 remove_file_from_cache(src);
858 update_file(o, 0, ren1->pair->one->sha1,
859 ren1->pair->one->mode, src);
860 }
861 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
862 } else {
863 struct merge_file_info mfi;
864 remove_file(o, 1, ren1_src, 1);
865 mfi = merge_file(o,
866 ren1->pair->one,
867 ren1->pair->two,
868 ren2->pair->two,
869 branch1,
870 branch2);
871 if (mfi.merge || !mfi.clean)
872 output(o, 1, "Renaming %s->%s", src, ren1_dst);
873
874 if (mfi.merge)
875 output(o, 2, "Auto-merging %s", ren1_dst);
876
877 if (!mfi.clean) {
878 output(o, 1, "CONFLICT (content): merge conflict in %s",
879 ren1_dst);
880 clean_merge = 0;
881
882 if (!o->call_depth)
883 update_stages(ren1_dst,
884 ren1->pair->one,
885 ren1->pair->two,
886 ren2->pair->two,
887 1 /* clear */);
888 }
889 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
890 }
891 } else {
892 /* Renamed in 1, maybe changed in 2 */
893 struct string_list_item *item;
894 /* we only use sha1 and mode of these */
895 struct diff_filespec src_other, dst_other;
896 int try_merge, stage = a_renames == renames1 ? 3: 2;
897
898 remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
899
900 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
901 src_other.mode = ren1->src_entry->stages[stage].mode;
902 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
903 dst_other.mode = ren1->dst_entry->stages[stage].mode;
904
905 try_merge = 0;
906
907 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
908 clean_merge = 0;
909 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
910 " directory %s added in %s",
911 ren1_src, ren1_dst, branch1,
912 ren1_dst, branch2);
913 conflict_rename_dir(o, ren1, branch1);
914 } else if (sha_eq(src_other.sha1, null_sha1)) {
915 clean_merge = 0;
916 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
917 "and deleted in %s",
918 ren1_src, ren1_dst, branch1,
919 branch2);
920 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
921 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
922 const char *new_path;
923 clean_merge = 0;
924 try_merge = 1;
925 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
926 "%s added in %s",
927 ren1_src, ren1_dst, branch1,
928 ren1_dst, branch2);
929 new_path = unique_path(o, ren1_dst, branch2);
930 output(o, 1, "Adding as %s instead", new_path);
931 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
932 } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
933 ren2 = item->util;
934 clean_merge = 0;
935 ren2->processed = 1;
936 output(o, 1, "CONFLICT (rename/rename): "
937 "Rename %s->%s in %s. "
938 "Rename %s->%s in %s",
939 ren1_src, ren1_dst, branch1,
940 ren2->pair->one->path, ren2->pair->two->path, branch2);
941 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
942 } else
943 try_merge = 1;
944
945 if (try_merge) {
946 struct diff_filespec *one, *a, *b;
947 struct merge_file_info mfi;
948 src_other.path = (char *)ren1_src;
949
950 one = ren1->pair->one;
951 if (a_renames == renames1) {
952 a = ren1->pair->two;
953 b = &src_other;
954 } else {
955 b = ren1->pair->two;
956 a = &src_other;
957 }
958 mfi = merge_file(o, one, a, b,
959 o->branch1, o->branch2);
960
961 if (mfi.clean &&
962 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
963 mfi.mode == ren1->pair->two->mode)
964 /*
965 * This messaged is part of
966 * t6022 test. If you change
967 * it update the test too.
968 */
969 output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
970 else {
971 if (mfi.merge || !mfi.clean)
972 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
973 if (mfi.merge)
974 output(o, 2, "Auto-merging %s", ren1_dst);
975 if (!mfi.clean) {
976 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
977 ren1_dst);
978 clean_merge = 0;
979
980 if (!o->call_depth)
981 update_stages(ren1_dst,
982 one, a, b, 1);
983 }
984 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
985 }
986 }
987 }
988 }
989 string_list_clear(&a_by_dst, 0);
990 string_list_clear(&b_by_dst, 0);
991
992 return clean_merge;
993 }
994
995 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
996 {
997 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
998 }
999
1000 /* Per entry merge function */
1001 static int process_entry(struct merge_options *o,
1002 const char *path, struct stage_data *entry)
1003 {
1004 /*
1005 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1006 print_index_entry("\tpath: ", entry);
1007 */
1008 int clean_merge = 1;
1009 unsigned o_mode = entry->stages[1].mode;
1010 unsigned a_mode = entry->stages[2].mode;
1011 unsigned b_mode = entry->stages[3].mode;
1012 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1013 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1014 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1015
1016 if (o_sha && (!a_sha || !b_sha)) {
1017 /* Case A: Deleted in one */
1018 if ((!a_sha && !b_sha) ||
1019 (sha_eq(a_sha, o_sha) && !b_sha) ||
1020 (!a_sha && sha_eq(b_sha, o_sha))) {
1021 /* Deleted in both or deleted in one and
1022 * unchanged in the other */
1023 if (a_sha)
1024 output(o, 2, "Removing %s", path);
1025 /* do not touch working file if it did not exist */
1026 remove_file(o, 1, path, !a_sha);
1027 } else {
1028 /* Deleted in one and changed in the other */
1029 clean_merge = 0;
1030 if (!a_sha) {
1031 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1032 "and modified in %s. Version %s of %s left in tree.",
1033 path, o->branch1,
1034 o->branch2, o->branch2, path);
1035 update_file(o, 0, b_sha, b_mode, path);
1036 } else {
1037 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1038 "and modified in %s. Version %s of %s left in tree.",
1039 path, o->branch2,
1040 o->branch1, o->branch1, path);
1041 update_file(o, 0, a_sha, a_mode, path);
1042 }
1043 }
1044
1045 } else if ((!o_sha && a_sha && !b_sha) ||
1046 (!o_sha && !a_sha && b_sha)) {
1047 /* Case B: Added in one. */
1048 const char *add_branch;
1049 const char *other_branch;
1050 unsigned mode;
1051 const unsigned char *sha;
1052 const char *conf;
1053
1054 if (a_sha) {
1055 add_branch = o->branch1;
1056 other_branch = o->branch2;
1057 mode = a_mode;
1058 sha = a_sha;
1059 conf = "file/directory";
1060 } else {
1061 add_branch = o->branch2;
1062 other_branch = o->branch1;
1063 mode = b_mode;
1064 sha = b_sha;
1065 conf = "directory/file";
1066 }
1067 if (string_list_has_string(&o->current_directory_set, path)) {
1068 const char *new_path = unique_path(o, path, add_branch);
1069 clean_merge = 0;
1070 output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1071 "Adding %s as %s",
1072 conf, path, other_branch, path, new_path);
1073 remove_file(o, 0, path, 0);
1074 update_file(o, 0, sha, mode, new_path);
1075 } else {
1076 output(o, 2, "Adding %s", path);
1077 update_file(o, 1, sha, mode, path);
1078 }
1079 } else if (a_sha && b_sha) {
1080 /* Case C: Added in both (check for same permissions) and */
1081 /* case D: Modified in both, but differently. */
1082 const char *reason = "content";
1083 struct merge_file_info mfi;
1084 struct diff_filespec one, a, b;
1085
1086 if (!o_sha) {
1087 reason = "add/add";
1088 o_sha = (unsigned char *)null_sha1;
1089 }
1090 output(o, 2, "Auto-merging %s", path);
1091 one.path = a.path = b.path = (char *)path;
1092 hashcpy(one.sha1, o_sha);
1093 one.mode = o_mode;
1094 hashcpy(a.sha1, a_sha);
1095 a.mode = a_mode;
1096 hashcpy(b.sha1, b_sha);
1097 b.mode = b_mode;
1098
1099 mfi = merge_file(o, &one, &a, &b,
1100 o->branch1, o->branch2);
1101
1102 clean_merge = mfi.clean;
1103 if (mfi.clean)
1104 update_file(o, 1, mfi.sha, mfi.mode, path);
1105 else if (S_ISGITLINK(mfi.mode))
1106 output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
1107 "- needs %s", path, sha1_to_hex(b.sha1));
1108 else {
1109 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1110 reason, path);
1111
1112 if (o->call_depth)
1113 update_file(o, 0, mfi.sha, mfi.mode, path);
1114 else
1115 update_file_flags(o, mfi.sha, mfi.mode, path,
1116 0 /* update_cache */, 1 /* update_working_directory */);
1117 }
1118 } else if (!o_sha && !a_sha && !b_sha) {
1119 /*
1120 * this entry was deleted altogether. a_mode == 0 means
1121 * we had that path and want to actively remove it.
1122 */
1123 remove_file(o, 1, path, !a_mode);
1124 } else
1125 die("Fatal merge failure, shouldn't happen.");
1126
1127 return clean_merge;
1128 }
1129
1130 int merge_trees(struct merge_options *o,
1131 struct tree *head,
1132 struct tree *merge,
1133 struct tree *common,
1134 struct tree **result)
1135 {
1136 int code, clean;
1137
1138 if (o->subtree_merge) {
1139 merge = shift_tree_object(head, merge);
1140 common = shift_tree_object(head, common);
1141 }
1142
1143 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1144 output(o, 0, "Already uptodate!");
1145 *result = head;
1146 return 1;
1147 }
1148
1149 code = git_merge_trees(o->call_depth, common, head, merge);
1150
1151 if (code != 0)
1152 die("merging of trees %s and %s failed",
1153 sha1_to_hex(head->object.sha1),
1154 sha1_to_hex(merge->object.sha1));
1155
1156 if (unmerged_cache()) {
1157 struct string_list *entries, *re_head, *re_merge;
1158 int i;
1159 string_list_clear(&o->current_file_set, 1);
1160 string_list_clear(&o->current_directory_set, 1);
1161 get_files_dirs(o, head);
1162 get_files_dirs(o, merge);
1163
1164 entries = get_unmerged();
1165 re_head = get_renames(o, head, common, head, merge, entries);
1166 re_merge = get_renames(o, merge, common, head, merge, entries);
1167 clean = process_renames(o, re_head, re_merge);
1168 for (i = 0; i < entries->nr; i++) {
1169 const char *path = entries->items[i].string;
1170 struct stage_data *e = entries->items[i].util;
1171 if (!e->processed
1172 && !process_entry(o, path, e))
1173 clean = 0;
1174 }
1175
1176 string_list_clear(re_merge, 0);
1177 string_list_clear(re_head, 0);
1178 string_list_clear(entries, 1);
1179
1180 }
1181 else
1182 clean = 1;
1183
1184 if (o->call_depth)
1185 *result = write_tree_from_memory(o);
1186
1187 return clean;
1188 }
1189
1190 static struct commit_list *reverse_commit_list(struct commit_list *list)
1191 {
1192 struct commit_list *next = NULL, *current, *backup;
1193 for (current = list; current; current = backup) {
1194 backup = current->next;
1195 current->next = next;
1196 next = current;
1197 }
1198 return next;
1199 }
1200
1201 /*
1202 * Merge the commits h1 and h2, return the resulting virtual
1203 * commit object and a flag indicating the cleanness of the merge.
1204 */
1205 int merge_recursive(struct merge_options *o,
1206 struct commit *h1,
1207 struct commit *h2,
1208 struct commit_list *ca,
1209 struct commit **result)
1210 {
1211 struct commit_list *iter;
1212 struct commit *merged_common_ancestors;
1213 struct tree *mrtree = mrtree;
1214 int clean;
1215
1216 if (show(o, 4)) {
1217 output(o, 4, "Merging:");
1218 output_commit_title(o, h1);
1219 output_commit_title(o, h2);
1220 }
1221
1222 if (!ca) {
1223 ca = get_merge_bases(h1, h2, 1);
1224 ca = reverse_commit_list(ca);
1225 }
1226
1227 if (show(o, 5)) {
1228 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1229 for (iter = ca; iter; iter = iter->next)
1230 output_commit_title(o, iter->item);
1231 }
1232
1233 merged_common_ancestors = pop_commit(&ca);
1234 if (merged_common_ancestors == NULL) {
1235 /* if there is no common ancestor, make an empty tree */
1236 struct tree *tree = xcalloc(1, sizeof(struct tree));
1237
1238 tree->object.parsed = 1;
1239 tree->object.type = OBJ_TREE;
1240 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1241 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1242 }
1243
1244 for (iter = ca; iter; iter = iter->next) {
1245 const char *saved_b1, *saved_b2;
1246 o->call_depth++;
1247 /*
1248 * When the merge fails, the result contains files
1249 * with conflict markers. The cleanness flag is
1250 * ignored, it was never actually used, as result of
1251 * merge_trees has always overwritten it: the committed
1252 * "conflicts" were already resolved.
1253 */
1254 discard_cache();
1255 saved_b1 = o->branch1;
1256 saved_b2 = o->branch2;
1257 o->branch1 = "Temporary merge branch 1";
1258 o->branch2 = "Temporary merge branch 2";
1259 merge_recursive(o, merged_common_ancestors, iter->item,
1260 NULL, &merged_common_ancestors);
1261 o->branch1 = saved_b1;
1262 o->branch2 = saved_b2;
1263 o->call_depth--;
1264
1265 if (!merged_common_ancestors)
1266 die("merge returned no commit");
1267 }
1268
1269 discard_cache();
1270 if (!o->call_depth)
1271 read_cache();
1272
1273 clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1274 &mrtree);
1275
1276 if (o->call_depth) {
1277 *result = make_virtual_commit(mrtree, "merged tree");
1278 commit_list_insert(h1, &(*result)->parents);
1279 commit_list_insert(h2, &(*result)->parents->next);
1280 }
1281 flush_output(o);
1282 return clean;
1283 }
1284
1285 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1286 {
1287 struct object *object;
1288
1289 object = deref_tag(parse_object(sha1), name, strlen(name));
1290 if (!object)
1291 return NULL;
1292 if (object->type == OBJ_TREE)
1293 return make_virtual_commit((struct tree*)object, name);
1294 if (object->type != OBJ_COMMIT)
1295 return NULL;
1296 if (parse_commit((struct commit *)object))
1297 return NULL;
1298 return (struct commit *)object;
1299 }
1300
1301 int merge_recursive_generic(struct merge_options *o,
1302 const unsigned char *head,
1303 const unsigned char *merge,
1304 int num_base_list,
1305 const unsigned char **base_list,
1306 struct commit **result)
1307 {
1308 int clean, index_fd;
1309 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1310 struct commit *head_commit = get_ref(head, o->branch1);
1311 struct commit *next_commit = get_ref(merge, o->branch2);
1312 struct commit_list *ca = NULL;
1313
1314 if (base_list) {
1315 int i;
1316 for (i = 0; i < num_base_list; ++i) {
1317 struct commit *base;
1318 if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1319 return error("Could not parse object '%s'",
1320 sha1_to_hex(base_list[i]));
1321 commit_list_insert(base, &ca);
1322 }
1323 }
1324
1325 index_fd = hold_locked_index(lock, 1);
1326 clean = merge_recursive(o, head_commit, next_commit, ca,
1327 result);
1328 if (active_cache_changed &&
1329 (write_cache(index_fd, active_cache, active_nr) ||
1330 commit_locked_index(lock)))
1331 return error("Unable to write index.");
1332
1333 return clean ? 0 : 1;
1334 }
1335
1336 static int merge_recursive_config(const char *var, const char *value, void *cb)
1337 {
1338 struct merge_options *o = cb;
1339 if (!strcasecmp(var, "merge.verbosity")) {
1340 o->verbosity = git_config_int(var, value);
1341 return 0;
1342 }
1343 if (!strcasecmp(var, "diff.renamelimit")) {
1344 o->diff_rename_limit = git_config_int(var, value);
1345 return 0;
1346 }
1347 if (!strcasecmp(var, "merge.renamelimit")) {
1348 o->merge_rename_limit = git_config_int(var, value);
1349 return 0;
1350 }
1351 return git_default_config(var, value, cb);
1352 }
1353
1354 void init_merge_options(struct merge_options *o)
1355 {
1356 memset(o, 0, sizeof(struct merge_options));
1357 o->verbosity = 2;
1358 o->buffer_output = 1;
1359 o->diff_rename_limit = -1;
1360 o->merge_rename_limit = -1;
1361 git_config(merge_recursive_config, o);
1362 if (getenv("GIT_MERGE_VERBOSITY"))
1363 o->verbosity =
1364 strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1365 if (o->verbosity >= 5)
1366 o->buffer_output = 0;
1367 strbuf_init(&o->obuf, 0);
1368 memset(&o->current_file_set, 0, sizeof(struct string_list));
1369 o->current_file_set.strdup_strings = 1;
1370 memset(&o->current_directory_set, 0, sizeof(struct string_list));
1371 o->current_directory_set.strdup_strings = 1;
1372 }