aab4c3458884455608466d377de8942f82b04aca
[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 "tree-walk.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "run-command.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18
19 /*
20 * A virtual commit has
21 * - (const char *)commit->util set to the name, and
22 * - *(int *)commit->object.sha1 set to the virtual id.
23 */
24
25 static unsigned commit_list_count(const struct commit_list *l)
26 {
27 unsigned c = 0;
28 for (; l; l = l->next )
29 c++;
30 return c;
31 }
32
33 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
34 {
35 struct commit *commit = xcalloc(1, sizeof(struct commit));
36 static unsigned virtual_id = 1;
37 commit->tree = tree;
38 commit->util = (void*)comment;
39 *(int*)commit->object.sha1 = virtual_id++;
40 /* avoid warnings */
41 commit->object.parsed = 1;
42 return commit;
43 }
44
45 /*
46 * Since we use get_tree_entry(), which does not put the read object into
47 * the object pool, we cannot rely on a == b.
48 */
49 static int sha_eq(const unsigned char *a, const unsigned char *b)
50 {
51 if (!a && !b)
52 return 2;
53 return a && b && hashcmp(a, b) == 0;
54 }
55
56 /*
57 * Since we want to write the index eventually, we cannot reuse the index
58 * for these (temporary) data.
59 */
60 struct stage_data
61 {
62 struct
63 {
64 unsigned mode;
65 unsigned char sha[20];
66 } stages[4];
67 unsigned processed:1;
68 };
69
70 static struct path_list current_file_set = {NULL, 0, 0, 1};
71 static struct path_list current_directory_set = {NULL, 0, 0, 1};
72
73 static int output_indent = 0;
74
75 static void output(const char *fmt, ...)
76 {
77 va_list args;
78 int i;
79 for (i = output_indent; i--;)
80 fputs(" ", stdout);
81 va_start(args, fmt);
82 vfprintf(stdout, fmt, args);
83 va_end(args);
84 fputc('\n', stdout);
85 }
86
87 static void output_commit_title(struct commit *commit)
88 {
89 int i;
90 for (i = output_indent; i--;)
91 fputs(" ", stdout);
92 if (commit->util)
93 printf("virtual %s\n", (char *)commit->util);
94 else {
95 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
96 if (parse_commit(commit) != 0)
97 printf("(bad commit)\n");
98 else {
99 const char *s;
100 int len;
101 for (s = commit->buffer; *s; s++)
102 if (*s == '\n' && s[1] == '\n') {
103 s += 2;
104 break;
105 }
106 for (len = 0; s[len] && '\n' != s[len]; len++)
107 ; /* do nothing */
108 printf("%.*s\n", len, s);
109 }
110 }
111 }
112
113 static const char *current_index_file = NULL;
114 static const char *original_index_file;
115 static const char *temporary_index_file;
116 static int cache_dirty = 0;
117
118 static int flush_cache(void)
119 {
120 /* flush temporary index */
121 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
122 int fd = hold_lock_file_for_update(lock, current_index_file, 1);
123 if (write_cache(fd, active_cache, active_nr) ||
124 close(fd) || commit_lock_file(lock))
125 die ("unable to write %s", current_index_file);
126 discard_cache();
127 cache_dirty = 0;
128 return 0;
129 }
130
131 static void setup_index(int temp)
132 {
133 current_index_file = temp ? temporary_index_file: original_index_file;
134 if (cache_dirty) {
135 discard_cache();
136 cache_dirty = 0;
137 }
138 unlink(temporary_index_file);
139 discard_cache();
140 }
141
142 static struct cache_entry *make_cache_entry(unsigned int mode,
143 const unsigned char *sha1, const char *path, int stage, int refresh)
144 {
145 int size, len;
146 struct cache_entry *ce;
147
148 if (!verify_path(path))
149 return NULL;
150
151 len = strlen(path);
152 size = cache_entry_size(len);
153 ce = xcalloc(1, size);
154
155 hashcpy(ce->sha1, sha1);
156 memcpy(ce->name, path, len);
157 ce->ce_flags = create_ce_flags(len, stage);
158 ce->ce_mode = create_ce_mode(mode);
159
160 if (refresh)
161 return refresh_cache_entry(ce, 0);
162
163 return ce;
164 }
165
166 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
167 const char *path, int stage, int refresh, int options)
168 {
169 struct cache_entry *ce;
170 if (!cache_dirty)
171 read_cache_from(current_index_file);
172 cache_dirty++;
173 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
174 if (!ce)
175 return error("cache_addinfo failed: %s", strerror(cache_errno));
176 return add_cache_entry(ce, options);
177 }
178
179 /*
180 * This is a global variable which is used in a number of places but
181 * only written to in the 'merge' function.
182 *
183 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
184 * don't update the working directory.
185 * 0 => Leave unmerged entries in the cache and update
186 * the working directory.
187 */
188 static int index_only = 0;
189
190 static int git_read_tree(struct tree *tree)
191 {
192 int rc;
193 struct object_list *trees = NULL;
194 struct unpack_trees_options opts;
195
196 if (cache_dirty)
197 die("read-tree with dirty cache");
198
199 memset(&opts, 0, sizeof(opts));
200 object_list_append(&tree->object, &trees);
201 rc = unpack_trees(trees, &opts);
202 cache_tree_free(&active_cache_tree);
203
204 if (rc == 0)
205 cache_dirty = 1;
206
207 return rc;
208 }
209
210 static int git_merge_trees(int index_only,
211 struct tree *common,
212 struct tree *head,
213 struct tree *merge)
214 {
215 int rc;
216 struct object_list *trees = NULL;
217 struct unpack_trees_options opts;
218
219 if (!cache_dirty) {
220 read_cache_from(current_index_file);
221 cache_dirty = 1;
222 }
223
224 memset(&opts, 0, sizeof(opts));
225 if (index_only)
226 opts.index_only = 1;
227 else
228 opts.update = 1;
229 opts.merge = 1;
230 opts.head_idx = 2;
231 opts.fn = threeway_merge;
232
233 object_list_append(&common->object, &trees);
234 object_list_append(&head->object, &trees);
235 object_list_append(&merge->object, &trees);
236
237 rc = unpack_trees(trees, &opts);
238 cache_tree_free(&active_cache_tree);
239
240 cache_dirty = 1;
241
242 return rc;
243 }
244
245 static struct tree *git_write_tree(void)
246 {
247 struct tree *result = NULL;
248
249 if (cache_dirty) {
250 unsigned i;
251 for (i = 0; i < active_nr; i++) {
252 struct cache_entry *ce = active_cache[i];
253 if (ce_stage(ce))
254 return NULL;
255 }
256 } else
257 read_cache_from(current_index_file);
258
259 if (!active_cache_tree)
260 active_cache_tree = cache_tree();
261
262 if (!cache_tree_fully_valid(active_cache_tree) &&
263 cache_tree_update(active_cache_tree,
264 active_cache, active_nr, 0, 0) < 0)
265 die("error building trees");
266
267 result = lookup_tree(active_cache_tree->sha1);
268
269 flush_cache();
270 cache_dirty = 0;
271
272 return result;
273 }
274
275 static int save_files_dirs(const unsigned char *sha1,
276 const char *base, int baselen, const char *path,
277 unsigned int mode, int stage)
278 {
279 int len = strlen(path);
280 char *newpath = xmalloc(baselen + len + 1);
281 memcpy(newpath, base, baselen);
282 memcpy(newpath + baselen, path, len);
283 newpath[baselen + len] = '\0';
284
285 if (S_ISDIR(mode))
286 path_list_insert(newpath, &current_directory_set);
287 else
288 path_list_insert(newpath, &current_file_set);
289 free(newpath);
290
291 return READ_TREE_RECURSIVE;
292 }
293
294 static int get_files_dirs(struct tree *tree)
295 {
296 int n;
297 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
298 return 0;
299 n = current_file_set.nr + current_directory_set.nr;
300 return n;
301 }
302
303 /*
304 * Returns a index_entry instance which doesn't have to correspond to
305 * a real cache entry in Git's index.
306 */
307 static struct stage_data *insert_stage_data(const char *path,
308 struct tree *o, struct tree *a, struct tree *b,
309 struct path_list *entries)
310 {
311 struct path_list_item *item;
312 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
313 get_tree_entry(o->object.sha1, path,
314 e->stages[1].sha, &e->stages[1].mode);
315 get_tree_entry(a->object.sha1, path,
316 e->stages[2].sha, &e->stages[2].mode);
317 get_tree_entry(b->object.sha1, path,
318 e->stages[3].sha, &e->stages[3].mode);
319 item = path_list_insert(path, entries);
320 item->util = e;
321 return e;
322 }
323
324 /*
325 * Create a dictionary mapping file names to stage_data objects. The
326 * dictionary contains one entry for every path with a non-zero stage entry.
327 */
328 static struct path_list *get_unmerged(void)
329 {
330 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
331 int i;
332
333 unmerged->strdup_paths = 1;
334 if (!cache_dirty) {
335 read_cache_from(current_index_file);
336 cache_dirty++;
337 }
338 for (i = 0; i < active_nr; i++) {
339 struct path_list_item *item;
340 struct stage_data *e;
341 struct cache_entry *ce = active_cache[i];
342 if (!ce_stage(ce))
343 continue;
344
345 item = path_list_lookup(ce->name, unmerged);
346 if (!item) {
347 item = path_list_insert(ce->name, unmerged);
348 item->util = xcalloc(1, sizeof(struct stage_data));
349 }
350 e = item->util;
351 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
352 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
353 }
354
355 return unmerged;
356 }
357
358 struct rename
359 {
360 struct diff_filepair *pair;
361 struct stage_data *src_entry;
362 struct stage_data *dst_entry;
363 unsigned processed:1;
364 };
365
366 /*
367 * Get information of all renames which occured between 'o_tree' and
368 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
369 * 'b_tree') to be able to associate the correct cache entries with
370 * the rename information. 'tree' is always equal to either a_tree or b_tree.
371 */
372 static struct path_list *get_renames(struct tree *tree,
373 struct tree *o_tree,
374 struct tree *a_tree,
375 struct tree *b_tree,
376 struct path_list *entries)
377 {
378 int i;
379 struct path_list *renames;
380 struct diff_options opts;
381
382 renames = xcalloc(1, sizeof(struct path_list));
383 diff_setup(&opts);
384 opts.recursive = 1;
385 opts.detect_rename = DIFF_DETECT_RENAME;
386 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
387 if (diff_setup_done(&opts) < 0)
388 die("diff setup failed");
389 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
390 diffcore_std(&opts);
391 for (i = 0; i < diff_queued_diff.nr; ++i) {
392 struct path_list_item *item;
393 struct rename *re;
394 struct diff_filepair *pair = diff_queued_diff.queue[i];
395 if (pair->status != 'R') {
396 diff_free_filepair(pair);
397 continue;
398 }
399 re = xmalloc(sizeof(*re));
400 re->processed = 0;
401 re->pair = pair;
402 item = path_list_lookup(re->pair->one->path, entries);
403 if (!item)
404 re->src_entry = insert_stage_data(re->pair->one->path,
405 o_tree, a_tree, b_tree, entries);
406 else
407 re->src_entry = item->util;
408
409 item = path_list_lookup(re->pair->two->path, entries);
410 if (!item)
411 re->dst_entry = insert_stage_data(re->pair->two->path,
412 o_tree, a_tree, b_tree, entries);
413 else
414 re->dst_entry = item->util;
415 item = path_list_insert(pair->one->path, renames);
416 item->util = re;
417 }
418 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
419 diff_queued_diff.nr = 0;
420 diff_flush(&opts);
421 return renames;
422 }
423
424 static int update_stages(const char *path, struct diff_filespec *o,
425 struct diff_filespec *a, struct diff_filespec *b,
426 int clear)
427 {
428 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
429 if (clear)
430 if (remove_file_from_cache(path))
431 return -1;
432 if (o)
433 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
434 return -1;
435 if (a)
436 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
437 return -1;
438 if (b)
439 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
440 return -1;
441 return 0;
442 }
443
444 static int remove_path(const char *name)
445 {
446 int ret, len;
447 char *slash, *dirs;
448
449 ret = unlink(name);
450 if (ret)
451 return ret;
452 len = strlen(name);
453 dirs = xmalloc(len+1);
454 memcpy(dirs, name, len);
455 dirs[len] = '\0';
456 while ((slash = strrchr(name, '/'))) {
457 *slash = '\0';
458 len = slash - name;
459 if (rmdir(name) != 0)
460 break;
461 }
462 free(dirs);
463 return ret;
464 }
465
466 static int remove_file(int clean, const char *path, int no_wd)
467 {
468 int update_cache = index_only || clean;
469 int update_working_directory = !index_only && !no_wd;
470
471 if (update_cache) {
472 if (!cache_dirty)
473 read_cache_from(current_index_file);
474 cache_dirty++;
475 if (remove_file_from_cache(path))
476 return -1;
477 }
478 if (update_working_directory) {
479 unlink(path);
480 if (errno != ENOENT || errno != EISDIR)
481 return -1;
482 remove_path(path);
483 }
484 return 0;
485 }
486
487 static char *unique_path(const char *path, const char *branch)
488 {
489 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
490 int suffix = 0;
491 struct stat st;
492 char *p = newpath + strlen(path);
493 strcpy(newpath, path);
494 *(p++) = '~';
495 strcpy(p, branch);
496 for (; *p; ++p)
497 if ('/' == *p)
498 *p = '_';
499 while (path_list_has_path(&current_file_set, newpath) ||
500 path_list_has_path(&current_directory_set, newpath) ||
501 lstat(newpath, &st) == 0)
502 sprintf(p, "_%d", suffix++);
503
504 path_list_insert(newpath, &current_file_set);
505 return newpath;
506 }
507
508 static int mkdir_p(const char *path, unsigned long mode)
509 {
510 /* path points to cache entries, so xstrdup before messing with it */
511 char *buf = xstrdup(path);
512 int result = safe_create_leading_directories(buf);
513 free(buf);
514 return result;
515 }
516
517 static void flush_buffer(int fd, const char *buf, unsigned long size)
518 {
519 while (size > 0) {
520 long ret = write_in_full(fd, buf, size);
521 if (ret < 0) {
522 /* Ignore epipe */
523 if (errno == EPIPE)
524 break;
525 die("merge-recursive: %s", strerror(errno));
526 } else if (!ret) {
527 die("merge-recursive: disk full?");
528 }
529 size -= ret;
530 buf += ret;
531 }
532 }
533
534 static void update_file_flags(const unsigned char *sha,
535 unsigned mode,
536 const char *path,
537 int update_cache,
538 int update_wd)
539 {
540 if (index_only)
541 update_wd = 0;
542
543 if (update_wd) {
544 char type[20];
545 void *buf;
546 unsigned long size;
547
548 buf = read_sha1_file(sha, type, &size);
549 if (!buf)
550 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
551 if (strcmp(type, blob_type) != 0)
552 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
553
554 if (S_ISREG(mode)) {
555 int fd;
556 if (mkdir_p(path, 0777))
557 die("failed to create path %s: %s", path, strerror(errno));
558 unlink(path);
559 if (mode & 0100)
560 mode = 0777;
561 else
562 mode = 0666;
563 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
564 if (fd < 0)
565 die("failed to open %s: %s", path, strerror(errno));
566 flush_buffer(fd, buf, size);
567 close(fd);
568 } else if (S_ISLNK(mode)) {
569 char *lnk = xmalloc(size + 1);
570 memcpy(lnk, buf, size);
571 lnk[size] = '\0';
572 mkdir_p(path, 0777);
573 unlink(lnk);
574 symlink(lnk, path);
575 } else
576 die("do not know what to do with %06o %s '%s'",
577 mode, sha1_to_hex(sha), path);
578 }
579 if (update_cache)
580 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
581 }
582
583 static void update_file(int clean,
584 const unsigned char *sha,
585 unsigned mode,
586 const char *path)
587 {
588 update_file_flags(sha, mode, path, index_only || clean, !index_only);
589 }
590
591 /* Low level file merging, update and removal */
592
593 struct merge_file_info
594 {
595 unsigned char sha[20];
596 unsigned mode;
597 unsigned clean:1,
598 merge:1;
599 };
600
601 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
602 {
603 unsigned long size;
604 char type[20];
605
606 if (!hashcmp(sha1, null_sha1)) {
607 mm->ptr = xstrdup("");
608 mm->size = 0;
609 return;
610 }
611
612 mm->ptr = read_sha1_file(sha1, type, &size);
613 if (!mm->ptr || strcmp(type, blob_type))
614 die("unable to read blob object %s", sha1_to_hex(sha1));
615 mm->size = size;
616 }
617
618 static struct merge_file_info merge_file(struct diff_filespec *o,
619 struct diff_filespec *a, struct diff_filespec *b,
620 const char *branch1, const char *branch2)
621 {
622 struct merge_file_info result;
623 result.merge = 0;
624 result.clean = 1;
625
626 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
627 result.clean = 0;
628 if (S_ISREG(a->mode)) {
629 result.mode = a->mode;
630 hashcpy(result.sha, a->sha1);
631 } else {
632 result.mode = b->mode;
633 hashcpy(result.sha, b->sha1);
634 }
635 } else {
636 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
637 result.merge = 1;
638
639 result.mode = a->mode == o->mode ? b->mode: a->mode;
640
641 if (sha_eq(a->sha1, o->sha1))
642 hashcpy(result.sha, b->sha1);
643 else if (sha_eq(b->sha1, o->sha1))
644 hashcpy(result.sha, a->sha1);
645 else if (S_ISREG(a->mode)) {
646 mmfile_t orig, src1, src2;
647 mmbuffer_t result_buf;
648 xpparam_t xpp;
649 char *name1, *name2;
650 int merge_status;
651
652 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
653 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
654
655 fill_mm(o->sha1, &orig);
656 fill_mm(a->sha1, &src1);
657 fill_mm(b->sha1, &src2);
658
659 memset(&xpp, 0, sizeof(xpp));
660 merge_status = xdl_merge(&orig,
661 &src1, name1,
662 &src2, name2,
663 &xpp, XDL_MERGE_ZEALOUS,
664 &result_buf);
665 free(name1);
666 free(name2);
667 free(orig.ptr);
668 free(src1.ptr);
669 free(src2.ptr);
670
671 if ((merge_status < 0) || !result_buf.ptr)
672 die("Failed to execute internal merge");
673
674 if (write_sha1_file(result_buf.ptr, result_buf.size,
675 blob_type, result.sha))
676 die("Unable to add %s to database",
677 a->path);
678
679 free(result_buf.ptr);
680 result.clean = (merge_status == 0);
681 } else {
682 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
683 die("cannot merge modes?");
684
685 hashcpy(result.sha, a->sha1);
686
687 if (!sha_eq(a->sha1, b->sha1))
688 result.clean = 0;
689 }
690 }
691
692 return result;
693 }
694
695 static void conflict_rename_rename(struct rename *ren1,
696 const char *branch1,
697 struct rename *ren2,
698 const char *branch2)
699 {
700 char *del[2];
701 int delp = 0;
702 const char *ren1_dst = ren1->pair->two->path;
703 const char *ren2_dst = ren2->pair->two->path;
704 const char *dst_name1 = ren1_dst;
705 const char *dst_name2 = ren2_dst;
706 if (path_list_has_path(&current_directory_set, ren1_dst)) {
707 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
708 output("%s is a directory in %s adding as %s instead",
709 ren1_dst, branch2, dst_name1);
710 remove_file(0, ren1_dst, 0);
711 }
712 if (path_list_has_path(&current_directory_set, ren2_dst)) {
713 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
714 output("%s is a directory in %s adding as %s instead",
715 ren2_dst, branch1, dst_name2);
716 remove_file(0, ren2_dst, 0);
717 }
718 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
719 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
720 while (delp--)
721 free(del[delp]);
722 }
723
724 static void conflict_rename_dir(struct rename *ren1,
725 const char *branch1)
726 {
727 char *new_path = unique_path(ren1->pair->two->path, branch1);
728 output("Renaming %s to %s instead", ren1->pair->one->path, new_path);
729 remove_file(0, ren1->pair->two->path, 0);
730 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
731 free(new_path);
732 }
733
734 static void conflict_rename_rename_2(struct rename *ren1,
735 const char *branch1,
736 struct rename *ren2,
737 const char *branch2)
738 {
739 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
740 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
741 output("Renaming %s to %s and %s to %s instead",
742 ren1->pair->one->path, new_path1,
743 ren2->pair->one->path, new_path2);
744 remove_file(0, ren1->pair->two->path, 0);
745 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
746 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
747 free(new_path2);
748 free(new_path1);
749 }
750
751 static int process_renames(struct path_list *a_renames,
752 struct path_list *b_renames,
753 const char *a_branch,
754 const char *b_branch)
755 {
756 int clean_merge = 1, i, j;
757 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
758 const struct rename *sre;
759
760 for (i = 0; i < a_renames->nr; i++) {
761 sre = a_renames->items[i].util;
762 path_list_insert(sre->pair->two->path, &a_by_dst)->util
763 = sre->dst_entry;
764 }
765 for (i = 0; i < b_renames->nr; i++) {
766 sre = b_renames->items[i].util;
767 path_list_insert(sre->pair->two->path, &b_by_dst)->util
768 = sre->dst_entry;
769 }
770
771 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
772 int compare;
773 char *src;
774 struct path_list *renames1, *renames2, *renames2Dst;
775 struct rename *ren1 = NULL, *ren2 = NULL;
776 const char *branch1, *branch2;
777 const char *ren1_src, *ren1_dst;
778
779 if (i >= a_renames->nr) {
780 compare = 1;
781 ren2 = b_renames->items[j++].util;
782 } else if (j >= b_renames->nr) {
783 compare = -1;
784 ren1 = a_renames->items[i++].util;
785 } else {
786 compare = strcmp(a_renames->items[i].path,
787 b_renames->items[j].path);
788 if (compare <= 0)
789 ren1 = a_renames->items[i++].util;
790 if (compare >= 0)
791 ren2 = b_renames->items[j++].util;
792 }
793
794 /* TODO: refactor, so that 1/2 are not needed */
795 if (ren1) {
796 renames1 = a_renames;
797 renames2 = b_renames;
798 renames2Dst = &b_by_dst;
799 branch1 = a_branch;
800 branch2 = b_branch;
801 } else {
802 struct rename *tmp;
803 renames1 = b_renames;
804 renames2 = a_renames;
805 renames2Dst = &a_by_dst;
806 branch1 = b_branch;
807 branch2 = a_branch;
808 tmp = ren2;
809 ren2 = ren1;
810 ren1 = tmp;
811 }
812 src = ren1->pair->one->path;
813
814 ren1->dst_entry->processed = 1;
815 ren1->src_entry->processed = 1;
816
817 if (ren1->processed)
818 continue;
819 ren1->processed = 1;
820
821 ren1_src = ren1->pair->one->path;
822 ren1_dst = ren1->pair->two->path;
823
824 if (ren2) {
825 const char *ren2_src = ren2->pair->one->path;
826 const char *ren2_dst = ren2->pair->two->path;
827 /* Renamed in 1 and renamed in 2 */
828 if (strcmp(ren1_src, ren2_src) != 0)
829 die("ren1.src != ren2.src");
830 ren2->dst_entry->processed = 1;
831 ren2->processed = 1;
832 if (strcmp(ren1_dst, ren2_dst) != 0) {
833 clean_merge = 0;
834 output("CONFLICT (rename/rename): "
835 "Rename %s->%s in branch %s "
836 "rename %s->%s in %s",
837 src, ren1_dst, branch1,
838 src, ren2_dst, branch2);
839 conflict_rename_rename(ren1, branch1, ren2, branch2);
840 } else {
841 struct merge_file_info mfi;
842 remove_file(1, ren1_src, 1);
843 mfi = merge_file(ren1->pair->one,
844 ren1->pair->two,
845 ren2->pair->two,
846 branch1,
847 branch2);
848 if (mfi.merge || !mfi.clean)
849 output("Renaming %s->%s", src, ren1_dst);
850
851 if (mfi.merge)
852 output("Auto-merging %s", ren1_dst);
853
854 if (!mfi.clean) {
855 output("CONFLICT (content): merge conflict in %s",
856 ren1_dst);
857 clean_merge = 0;
858
859 if (!index_only)
860 update_stages(ren1_dst,
861 ren1->pair->one,
862 ren1->pair->two,
863 ren2->pair->two,
864 1 /* clear */);
865 }
866 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
867 }
868 } else {
869 /* Renamed in 1, maybe changed in 2 */
870 struct path_list_item *item;
871 /* we only use sha1 and mode of these */
872 struct diff_filespec src_other, dst_other;
873 int try_merge, stage = a_renames == renames1 ? 3: 2;
874
875 remove_file(1, ren1_src, index_only);
876
877 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
878 src_other.mode = ren1->src_entry->stages[stage].mode;
879 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
880 dst_other.mode = ren1->dst_entry->stages[stage].mode;
881
882 try_merge = 0;
883
884 if (path_list_has_path(&current_directory_set, ren1_dst)) {
885 clean_merge = 0;
886 output("CONFLICT (rename/directory): Rename %s->%s in %s "
887 " directory %s added in %s",
888 ren1_src, ren1_dst, branch1,
889 ren1_dst, branch2);
890 conflict_rename_dir(ren1, branch1);
891 } else if (sha_eq(src_other.sha1, null_sha1)) {
892 clean_merge = 0;
893 output("CONFLICT (rename/delete): Rename %s->%s in %s "
894 "and deleted in %s",
895 ren1_src, ren1_dst, branch1,
896 branch2);
897 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
898 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
899 const char *new_path;
900 clean_merge = 0;
901 try_merge = 1;
902 output("CONFLICT (rename/add): Rename %s->%s in %s. "
903 "%s added in %s",
904 ren1_src, ren1_dst, branch1,
905 ren1_dst, branch2);
906 new_path = unique_path(ren1_dst, branch2);
907 output("Adding as %s instead", new_path);
908 update_file(0, dst_other.sha1, dst_other.mode, new_path);
909 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
910 ren2 = item->util;
911 clean_merge = 0;
912 ren2->processed = 1;
913 output("CONFLICT (rename/rename): Rename %s->%s in %s. "
914 "Rename %s->%s in %s",
915 ren1_src, ren1_dst, branch1,
916 ren2->pair->one->path, ren2->pair->two->path, branch2);
917 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
918 } else
919 try_merge = 1;
920
921 if (try_merge) {
922 struct diff_filespec *o, *a, *b;
923 struct merge_file_info mfi;
924 src_other.path = (char *)ren1_src;
925
926 o = ren1->pair->one;
927 if (a_renames == renames1) {
928 a = ren1->pair->two;
929 b = &src_other;
930 } else {
931 b = ren1->pair->two;
932 a = &src_other;
933 }
934 mfi = merge_file(o, a, b,
935 a_branch, b_branch);
936
937 if (mfi.merge || !mfi.clean)
938 output("Renaming %s => %s", ren1_src, ren1_dst);
939 if (mfi.merge)
940 output("Auto-merging %s", ren1_dst);
941 if (!mfi.clean) {
942 output("CONFLICT (rename/modify): Merge conflict in %s",
943 ren1_dst);
944 clean_merge = 0;
945
946 if (!index_only)
947 update_stages(ren1_dst,
948 o, a, b, 1);
949 }
950 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
951 }
952 }
953 }
954 path_list_clear(&a_by_dst, 0);
955 path_list_clear(&b_by_dst, 0);
956
957 return clean_merge;
958 }
959
960 static unsigned char *has_sha(const unsigned char *sha)
961 {
962 return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
963 }
964
965 /* Per entry merge function */
966 static int process_entry(const char *path, struct stage_data *entry,
967 const char *branch1,
968 const char *branch2)
969 {
970 /*
971 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
972 print_index_entry("\tpath: ", entry);
973 */
974 int clean_merge = 1;
975 unsigned char *o_sha = has_sha(entry->stages[1].sha);
976 unsigned char *a_sha = has_sha(entry->stages[2].sha);
977 unsigned char *b_sha = has_sha(entry->stages[3].sha);
978 unsigned o_mode = entry->stages[1].mode;
979 unsigned a_mode = entry->stages[2].mode;
980 unsigned b_mode = entry->stages[3].mode;
981
982 if (o_sha && (!a_sha || !b_sha)) {
983 /* Case A: Deleted in one */
984 if ((!a_sha && !b_sha) ||
985 (sha_eq(a_sha, o_sha) && !b_sha) ||
986 (!a_sha && sha_eq(b_sha, o_sha))) {
987 /* Deleted in both or deleted in one and
988 * unchanged in the other */
989 if (a_sha)
990 output("Removing %s", path);
991 /* do not touch working file if it did not exist */
992 remove_file(1, path, !a_sha);
993 } else {
994 /* Deleted in one and changed in the other */
995 clean_merge = 0;
996 if (!a_sha) {
997 output("CONFLICT (delete/modify): %s deleted in %s "
998 "and modified in %s. Version %s of %s left in tree.",
999 path, branch1,
1000 branch2, branch2, path);
1001 update_file(0, b_sha, b_mode, path);
1002 } else {
1003 output("CONFLICT (delete/modify): %s deleted in %s "
1004 "and modified in %s. Version %s of %s left in tree.",
1005 path, branch2,
1006 branch1, branch1, path);
1007 update_file(0, a_sha, a_mode, path);
1008 }
1009 }
1010
1011 } else if ((!o_sha && a_sha && !b_sha) ||
1012 (!o_sha && !a_sha && b_sha)) {
1013 /* Case B: Added in one. */
1014 const char *add_branch;
1015 const char *other_branch;
1016 unsigned mode;
1017 const unsigned char *sha;
1018 const char *conf;
1019
1020 if (a_sha) {
1021 add_branch = branch1;
1022 other_branch = branch2;
1023 mode = a_mode;
1024 sha = a_sha;
1025 conf = "file/directory";
1026 } else {
1027 add_branch = branch2;
1028 other_branch = branch1;
1029 mode = b_mode;
1030 sha = b_sha;
1031 conf = "directory/file";
1032 }
1033 if (path_list_has_path(&current_directory_set, path)) {
1034 const char *new_path = unique_path(path, add_branch);
1035 clean_merge = 0;
1036 output("CONFLICT (%s): There is a directory with name %s in %s. "
1037 "Adding %s as %s",
1038 conf, path, other_branch, path, new_path);
1039 remove_file(0, path, 0);
1040 update_file(0, sha, mode, new_path);
1041 } else {
1042 output("Adding %s", path);
1043 update_file(1, sha, mode, path);
1044 }
1045 } else if (a_sha && b_sha) {
1046 /* Case C: Added in both (check for same permissions) and */
1047 /* case D: Modified in both, but differently. */
1048 const char *reason = "content";
1049 struct merge_file_info mfi;
1050 struct diff_filespec o, a, b;
1051
1052 if (!o_sha) {
1053 reason = "add/add";
1054 o_sha = (unsigned char *)null_sha1;
1055 }
1056 output("Auto-merging %s", path);
1057 o.path = a.path = b.path = (char *)path;
1058 hashcpy(o.sha1, o_sha);
1059 o.mode = o_mode;
1060 hashcpy(a.sha1, a_sha);
1061 a.mode = a_mode;
1062 hashcpy(b.sha1, b_sha);
1063 b.mode = b_mode;
1064
1065 mfi = merge_file(&o, &a, &b,
1066 branch1, branch2);
1067
1068 if (mfi.clean)
1069 update_file(1, mfi.sha, mfi.mode, path);
1070 else {
1071 clean_merge = 0;
1072 output("CONFLICT (%s): Merge conflict in %s",
1073 reason, path);
1074
1075 if (index_only)
1076 update_file(0, mfi.sha, mfi.mode, path);
1077 else
1078 update_file_flags(mfi.sha, mfi.mode, path,
1079 0 /* update_cache */, 1 /* update_working_directory */);
1080 }
1081 } else
1082 die("Fatal merge failure, shouldn't happen.");
1083
1084 return clean_merge;
1085 }
1086
1087 static int merge_trees(struct tree *head,
1088 struct tree *merge,
1089 struct tree *common,
1090 const char *branch1,
1091 const char *branch2,
1092 struct tree **result)
1093 {
1094 int code, clean;
1095 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1096 output("Already uptodate!");
1097 *result = head;
1098 return 1;
1099 }
1100
1101 code = git_merge_trees(index_only, common, head, merge);
1102
1103 if (code != 0)
1104 die("merging of trees %s and %s failed",
1105 sha1_to_hex(head->object.sha1),
1106 sha1_to_hex(merge->object.sha1));
1107
1108 *result = git_write_tree();
1109
1110 if (!*result) {
1111 struct path_list *entries, *re_head, *re_merge;
1112 int i;
1113 path_list_clear(&current_file_set, 1);
1114 path_list_clear(&current_directory_set, 1);
1115 get_files_dirs(head);
1116 get_files_dirs(merge);
1117
1118 entries = get_unmerged();
1119 re_head = get_renames(head, common, head, merge, entries);
1120 re_merge = get_renames(merge, common, head, merge, entries);
1121 clean = process_renames(re_head, re_merge,
1122 branch1, branch2);
1123 for (i = 0; i < entries->nr; i++) {
1124 const char *path = entries->items[i].path;
1125 struct stage_data *e = entries->items[i].util;
1126 if (e->processed)
1127 continue;
1128 if (!process_entry(path, e, branch1, branch2))
1129 clean = 0;
1130 }
1131 if (cache_dirty)
1132 flush_cache();
1133
1134 path_list_clear(re_merge, 0);
1135 path_list_clear(re_head, 0);
1136 path_list_clear(entries, 1);
1137
1138 if (clean || index_only)
1139 *result = git_write_tree();
1140 else
1141 *result = NULL;
1142 } else {
1143 clean = 1;
1144 printf("merging of trees %s and %s resulted in %s\n",
1145 sha1_to_hex(head->object.sha1),
1146 sha1_to_hex(merge->object.sha1),
1147 sha1_to_hex((*result)->object.sha1));
1148 }
1149
1150 return clean;
1151 }
1152
1153 static struct commit_list *reverse_commit_list(struct commit_list *list)
1154 {
1155 struct commit_list *next = NULL, *current, *backup;
1156 for (current = list; current; current = backup) {
1157 backup = current->next;
1158 current->next = next;
1159 next = current;
1160 }
1161 return next;
1162 }
1163
1164 /*
1165 * Merge the commits h1 and h2, return the resulting virtual
1166 * commit object and a flag indicating the cleaness of the merge.
1167 */
1168 static int merge(struct commit *h1,
1169 struct commit *h2,
1170 const char *branch1,
1171 const char *branch2,
1172 int call_depth /* =0 */,
1173 struct commit *ancestor /* =None */,
1174 struct commit **result)
1175 {
1176 struct commit_list *ca = NULL, *iter;
1177 struct commit *merged_common_ancestors;
1178 struct tree *mrtree;
1179 int clean;
1180
1181 output("Merging:");
1182 output_commit_title(h1);
1183 output_commit_title(h2);
1184
1185 if (ancestor)
1186 commit_list_insert(ancestor, &ca);
1187 else
1188 ca = reverse_commit_list(get_merge_bases(h1, h2, 1));
1189
1190 output("found %u common ancestor(s):", commit_list_count(ca));
1191 for (iter = ca; iter; iter = iter->next)
1192 output_commit_title(iter->item);
1193
1194 merged_common_ancestors = pop_commit(&ca);
1195 if (merged_common_ancestors == NULL) {
1196 /* if there is no common ancestor, make an empty tree */
1197 struct tree *tree = xcalloc(1, sizeof(struct tree));
1198
1199 tree->object.parsed = 1;
1200 tree->object.type = OBJ_TREE;
1201 write_sha1_file(NULL, 0, tree_type, tree->object.sha1);
1202 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1203 }
1204
1205 for (iter = ca; iter; iter = iter->next) {
1206 output_indent = call_depth + 1;
1207 /*
1208 * When the merge fails, the result contains files
1209 * with conflict markers. The cleanness flag is
1210 * ignored, it was never acutally used, as result of
1211 * merge_trees has always overwritten it: the commited
1212 * "conflicts" were already resolved.
1213 */
1214 merge(merged_common_ancestors, iter->item,
1215 "Temporary merge branch 1",
1216 "Temporary merge branch 2",
1217 call_depth + 1,
1218 NULL,
1219 &merged_common_ancestors);
1220 output_indent = call_depth;
1221
1222 if (!merged_common_ancestors)
1223 die("merge returned no commit");
1224 }
1225
1226 if (call_depth == 0) {
1227 setup_index(0 /* $GIT_DIR/index */);
1228 index_only = 0;
1229 } else {
1230 setup_index(1 /* temporary index */);
1231 git_read_tree(h1->tree);
1232 index_only = 1;
1233 }
1234
1235 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1236 branch1, branch2, &mrtree);
1237
1238 if (!ancestor && (clean || index_only)) {
1239 *result = make_virtual_commit(mrtree, "merged tree");
1240 commit_list_insert(h1, &(*result)->parents);
1241 commit_list_insert(h2, &(*result)->parents->next);
1242 } else
1243 *result = NULL;
1244
1245 return clean;
1246 }
1247
1248 static const char *better_branch_name(const char *branch)
1249 {
1250 static char githead_env[8 + 40 + 1];
1251 char *name;
1252
1253 if (strlen(branch) != 40)
1254 return branch;
1255 sprintf(githead_env, "GITHEAD_%s", branch);
1256 name = getenv(githead_env);
1257 return name ? name : branch;
1258 }
1259
1260 static struct commit *get_ref(const char *ref)
1261 {
1262 unsigned char sha1[20];
1263 struct object *object;
1264
1265 if (get_sha1(ref, sha1))
1266 die("Could not resolve ref '%s'", ref);
1267 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1268 if (object->type == OBJ_TREE)
1269 return make_virtual_commit((struct tree*)object,
1270 better_branch_name(ref));
1271 if (object->type != OBJ_COMMIT)
1272 return NULL;
1273 if (parse_commit((struct commit *)object))
1274 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1275 return (struct commit *)object;
1276 }
1277
1278 int main(int argc, char *argv[])
1279 {
1280 static const char *bases[2];
1281 static unsigned bases_count = 0;
1282 int i, clean;
1283 const char *branch1, *branch2;
1284 struct commit *result, *h1, *h2;
1285
1286 git_config(git_default_config); /* core.filemode */
1287 original_index_file = getenv(INDEX_ENVIRONMENT);
1288
1289 if (!original_index_file)
1290 original_index_file = xstrdup(git_path("index"));
1291
1292 temporary_index_file = xstrdup(git_path("mrg-rcrsv-tmp-idx"));
1293
1294 if (argc < 4)
1295 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1296
1297 for (i = 1; i < argc; ++i) {
1298 if (!strcmp(argv[i], "--"))
1299 break;
1300 if (bases_count < sizeof(bases)/sizeof(*bases))
1301 bases[bases_count++] = argv[i];
1302 }
1303 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1304 die("Not handling anything other than two heads merge.");
1305
1306 branch1 = argv[++i];
1307 branch2 = argv[++i];
1308
1309 h1 = get_ref(branch1);
1310 h2 = get_ref(branch2);
1311
1312 branch1 = better_branch_name(branch1);
1313 branch2 = better_branch_name(branch2);
1314 printf("Merging %s with %s\n", branch1, branch2);
1315
1316 if (bases_count == 1) {
1317 struct commit *ancestor = get_ref(bases[0]);
1318 clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
1319 } else
1320 clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
1321
1322 if (cache_dirty)
1323 flush_cache();
1324
1325 return clean ? 0: 1;
1326 }
1327
1328 /*
1329 vim: sw=8 noet
1330 */