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[git/debian.git] / merge-recursive.c
blob611cd95cf597b0ccf06cf9b4318eb34a86a4c05a
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 <stdarg.h>
7 #include <string.h>
8 #include <assert.h>
9 #include <sys/wait.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <time.h>
13 #include "cache.h"
14 #include "cache-tree.h"
15 #include "commit.h"
16 #include "blob.h"
17 #include "tree-walk.h"
18 #include "diff.h"
19 #include "diffcore.h"
20 #include "run-command.h"
21 #include "tag.h"
22 #include "unpack-trees.h"
23 #include "path-list.h"
24
25 /*
26 * A virtual commit has
27 * - (const char *)commit->util set to the name, and
28 * - *(int *)commit->object.sha1 set to the virtual id.
29 */
30
31 static unsigned commit_list_count(const struct commit_list *l)
32 {
33 unsigned c = 0;
34 for (; l; l = l->next )
35 c++;
36 return c;
37 }
38
39 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
40 {
41 struct commit *commit = xcalloc(1, sizeof(struct commit));
42 static unsigned virtual_id = 1;
43 commit->tree = tree;
44 commit->util = (void*)comment;
45 *(int*)commit->object.sha1 = virtual_id++;
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 struct path_list current_file_set = {NULL, 0, 0, 1};
77 static struct path_list current_directory_set = {NULL, 0, 0, 1};
78
79 static int output_indent = 0;
80
81 static void output(const char *fmt, ...)
82 {
83 va_list args;
84 int i;
85 for (i = output_indent; i--;)
86 fputs(" ", stdout);
87 va_start(args, fmt);
88 vfprintf(stdout, fmt, args);
89 va_end(args);
90 fputc('\n', stdout);
91 }
92
93 static void output_commit_title(struct commit *commit)
94 {
95 int i;
96 for (i = output_indent; i--;)
97 fputs(" ", stdout);
98 if (commit->util)
99 printf("virtual %s\n", (char *)commit->util);
100 else {
101 printf("%s ", sha1_to_hex(commit->object.sha1));
102 if (parse_commit(commit) != 0)
103 printf("(bad commit)\n");
104 else {
105 const char *s;
106 int len;
107 for (s = commit->buffer; *s; s++)
108 if (*s == '\n' && s[1] == '\n') {
109 s += 2;
110 break;
111 }
112 for (len = 0; s[len] && '\n' != s[len]; len++)
113 ; /* do nothing */
114 printf("%.*s\n", len, s);
115 }
116 }
117 }
118
119 static const char *current_index_file = NULL;
120 static const char *original_index_file;
121 static const char *temporary_index_file;
122 static int cache_dirty = 0;
123
124 static int flush_cache(void)
125 {
126 /* flush temporary index */
127 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
128 int fd = hold_lock_file_for_update(lock, current_index_file, 1);
129 if (write_cache(fd, active_cache, active_nr) ||
130 close(fd) || commit_lock_file(lock))
131 die ("unable to write %s", current_index_file);
132 discard_cache();
133 cache_dirty = 0;
134 return 0;
135 }
136
137 static void setup_index(int temp)
138 {
139 current_index_file = temp ? temporary_index_file: original_index_file;
140 if (cache_dirty) {
141 discard_cache();
142 cache_dirty = 0;
143 }
144 unlink(temporary_index_file);
145 discard_cache();
146 }
147
148 static struct cache_entry *make_cache_entry(unsigned int mode,
149 const unsigned char *sha1, const char *path, int stage, int refresh)
150 {
151 int size, len;
152 struct cache_entry *ce;
153
154 if (!verify_path(path))
155 return NULL;
156
157 len = strlen(path);
158 size = cache_entry_size(len);
159 ce = xcalloc(1, size);
160
161 hashcpy(ce->sha1, sha1);
162 memcpy(ce->name, path, len);
163 ce->ce_flags = create_ce_flags(len, stage);
164 ce->ce_mode = create_ce_mode(mode);
165
166 if (refresh)
167 return refresh_cache_entry(ce, 0);
168
169 return ce;
170 }
171
172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
173 const char *path, int stage, int refresh, int options)
174 {
175 struct cache_entry *ce;
176 if (!cache_dirty)
177 read_cache_from(current_index_file);
178 cache_dirty++;
179 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
180 if (!ce)
181 return error("cache_addinfo failed: %s", strerror(cache_errno));
182 return add_cache_entry(ce, options);
183 }
184
185 /*
186 * This is a global variable which is used in a number of places but
187 * only written to in the 'merge' function.
188 *
189 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
190 * don't update the working directory.
191 * 0 => Leave unmerged entries in the cache and update
192 * the working directory.
193 */
194 static int index_only = 0;
195
196 static int git_read_tree(struct tree *tree)
197 {
198 int rc;
199 struct object_list *trees = NULL;
200 struct unpack_trees_options opts;
201
202 if (cache_dirty)
203 die("read-tree with dirty cache");
204
205 memset(&opts, 0, sizeof(opts));
206 object_list_append(&tree->object, &trees);
207 rc = unpack_trees(trees, &opts);
208 cache_tree_free(&active_cache_tree);
209
210 if (rc == 0)
211 cache_dirty = 1;
212
213 return rc;
214 }
215
216 static int git_merge_trees(int index_only,
217 struct tree *common,
218 struct tree *head,
219 struct tree *merge)
220 {
221 int rc;
222 struct object_list *trees = NULL;
223 struct unpack_trees_options opts;
224
225 if (!cache_dirty) {
226 read_cache_from(current_index_file);
227 cache_dirty = 1;
228 }
229
230 memset(&opts, 0, sizeof(opts));
231 if (index_only)
232 opts.index_only = 1;
233 else
234 opts.update = 1;
235 opts.merge = 1;
236 opts.head_idx = 2;
237 opts.fn = threeway_merge;
238
239 object_list_append(&common->object, &trees);
240 object_list_append(&head->object, &trees);
241 object_list_append(&merge->object, &trees);
242
243 rc = unpack_trees(trees, &opts);
244 cache_tree_free(&active_cache_tree);
245
246 cache_dirty = 1;
247
248 return rc;
249 }
250
251 static struct tree *git_write_tree(void)
252 {
253 struct tree *result = NULL;
254
255 if (cache_dirty) {
256 unsigned i;
257 for (i = 0; i < active_nr; i++) {
258 struct cache_entry *ce = active_cache[i];
259 if (ce_stage(ce))
260 return NULL;
261 }
262 } else
263 read_cache_from(current_index_file);
264
265 if (!active_cache_tree)
266 active_cache_tree = cache_tree();
267
268 if (!cache_tree_fully_valid(active_cache_tree) &&
269 cache_tree_update(active_cache_tree,
270 active_cache, active_nr, 0, 0) < 0)
271 die("error building trees");
272
273 result = lookup_tree(active_cache_tree->sha1);
274
275 flush_cache();
276 cache_dirty = 0;
277
278 return result;
279 }
280
281 static int save_files_dirs(const unsigned char *sha1,
282 const char *base, int baselen, const char *path,
283 unsigned int mode, int stage)
284 {
285 int len = strlen(path);
286 char *newpath = xmalloc(baselen + len + 1);
287 memcpy(newpath, base, baselen);
288 memcpy(newpath + baselen, path, len);
289 newpath[baselen + len] = '\0';
290
291 if (S_ISDIR(mode))
292 path_list_insert(newpath, &current_directory_set);
293 else
294 path_list_insert(newpath, &current_file_set);
295 free(newpath);
296
297 return READ_TREE_RECURSIVE;
298 }
299
300 static int get_files_dirs(struct tree *tree)
301 {
302 int n;
303 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
304 return 0;
305 n = current_file_set.nr + current_directory_set.nr;
306 return n;
307 }
308
309 /*
310 * Returns a index_entry instance which doesn't have to correspond to
311 * a real cache entry in Git's index.
312 */
313 static struct stage_data *insert_stage_data(const char *path,
314 struct tree *o, struct tree *a, struct tree *b,
315 struct path_list *entries)
316 {
317 struct path_list_item *item;
318 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
319 get_tree_entry(o->object.sha1, path,
320 e->stages[1].sha, &e->stages[1].mode);
321 get_tree_entry(a->object.sha1, path,
322 e->stages[2].sha, &e->stages[2].mode);
323 get_tree_entry(b->object.sha1, path,
324 e->stages[3].sha, &e->stages[3].mode);
325 item = path_list_insert(path, entries);
326 item->util = e;
327 return e;
328 }
329
330 /*
331 * Create a dictionary mapping file names to stage_data objects. The
332 * dictionary contains one entry for every path with a non-zero stage entry.
333 */
334 static struct path_list *get_unmerged(void)
335 {
336 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
337 int i;
338
339 unmerged->strdup_paths = 1;
340 if (!cache_dirty) {
341 read_cache_from(current_index_file);
342 cache_dirty++;
343 }
344 for (i = 0; i < active_nr; i++) {
345 struct path_list_item *item;
346 struct stage_data *e;
347 struct cache_entry *ce = active_cache[i];
348 if (!ce_stage(ce))
349 continue;
350
351 item = path_list_lookup(ce->name, unmerged);
352 if (!item) {
353 item = path_list_insert(ce->name, unmerged);
354 item->util = xcalloc(1, sizeof(struct stage_data));
355 }
356 e = item->util;
357 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
358 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
359 }
360
361 return unmerged;
362 }
363
364 struct rename
365 {
366 struct diff_filepair *pair;
367 struct stage_data *src_entry;
368 struct stage_data *dst_entry;
369 unsigned processed:1;
370 };
371
372 /*
373 * Get information of all renames which occured between 'o_tree' and
374 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
375 * 'b_tree') to be able to associate the correct cache entries with
376 * the rename information. 'tree' is always equal to either a_tree or b_tree.
377 */
378 static struct path_list *get_renames(struct tree *tree,
379 struct tree *o_tree,
380 struct tree *a_tree,
381 struct tree *b_tree,
382 struct path_list *entries)
383 {
384 int i;
385 struct path_list *renames;
386 struct diff_options opts;
387
388 renames = xcalloc(1, sizeof(struct path_list));
389 diff_setup(&opts);
390 opts.recursive = 1;
391 opts.detect_rename = DIFF_DETECT_RENAME;
392 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
393 if (diff_setup_done(&opts) < 0)
394 die("diff setup failed");
395 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
396 diffcore_std(&opts);
397 for (i = 0; i < diff_queued_diff.nr; ++i) {
398 struct path_list_item *item;
399 struct rename *re;
400 struct diff_filepair *pair = diff_queued_diff.queue[i];
401 if (pair->status != 'R') {
402 diff_free_filepair(pair);
403 continue;
404 }
405 re = xmalloc(sizeof(*re));
406 re->processed = 0;
407 re->pair = pair;
408 item = path_list_lookup(re->pair->one->path, entries);
409 if (!item)
410 re->src_entry = insert_stage_data(re->pair->one->path,
411 o_tree, a_tree, b_tree, entries);
412 else
413 re->src_entry = item->util;
414
415 item = path_list_lookup(re->pair->two->path, entries);
416 if (!item)
417 re->dst_entry = insert_stage_data(re->pair->two->path,
418 o_tree, a_tree, b_tree, entries);
419 else
420 re->dst_entry = item->util;
421 item = path_list_insert(pair->one->path, renames);
422 item->util = re;
423 }
424 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
425 diff_queued_diff.nr = 0;
426 diff_flush(&opts);
427 return renames;
428 }
429
430 int update_stages(const char *path, struct diff_filespec *o,
431 struct diff_filespec *a, struct diff_filespec *b, int clear)
432 {
433 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
434 if (clear)
435 if (remove_file_from_cache(path))
436 return -1;
437 if (o)
438 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
439 return -1;
440 if (a)
441 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
442 return -1;
443 if (b)
444 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
445 return -1;
446 return 0;
447 }
448
449 static int remove_path(const char *name)
450 {
451 int ret, len;
452 char *slash, *dirs;
453
454 ret = unlink(name);
455 if (ret)
456 return ret;
457 len = strlen(name);
458 dirs = xmalloc(len+1);
459 memcpy(dirs, name, len);
460 dirs[len] = '\0';
461 while ((slash = strrchr(name, '/'))) {
462 *slash = '\0';
463 len = slash - name;
464 if (rmdir(name) != 0)
465 break;
466 }
467 free(dirs);
468 return ret;
469 }
470
471 int remove_file(int clean, const char *path)
472 {
473 int update_cache = index_only || clean;
474 int update_working_directory = !index_only;
475
476 if (update_cache) {
477 if (!cache_dirty)
478 read_cache_from(current_index_file);
479 cache_dirty++;
480 if (remove_file_from_cache(path))
481 return -1;
482 }
483 if (update_working_directory)
484 {
485 unlink(path);
486 if (errno != ENOENT || errno != EISDIR)
487 return -1;
488 remove_path(path);
489 }
490 return 0;
491 }
492
493 static char *unique_path(const char *path, const char *branch)
494 {
495 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
496 int suffix = 0;
497 struct stat st;
498 char *p = newpath + strlen(path);
499 strcpy(newpath, path);
500 *(p++) = '~';
501 strcpy(p, branch);
502 for (; *p; ++p)
503 if ('/' == *p)
504 *p = '_';
505 while (path_list_has_path(&current_file_set, newpath) ||
506 path_list_has_path(&current_directory_set, newpath) ||
507 lstat(newpath, &st) == 0)
508 sprintf(p, "_%d", suffix++);
509
510 path_list_insert(newpath, &current_file_set);
511 return newpath;
512 }
513
514 static int mkdir_p(const char *path, unsigned long mode)
515 {
516 /* path points to cache entries, so xstrdup before messing with it */
517 char *buf = xstrdup(path);
518 int result = safe_create_leading_directories(buf);
519 free(buf);
520 return result;
521 }
522
523 static void flush_buffer(int fd, const char *buf, unsigned long size)
524 {
525 while (size > 0) {
526 long ret = xwrite(fd, buf, size);
527 if (ret < 0) {
528 /* Ignore epipe */
529 if (errno == EPIPE)
530 break;
531 die("merge-recursive: %s", strerror(errno));
532 } else if (!ret) {
533 die("merge-recursive: disk full?");
534 }
535 size -= ret;
536 buf += ret;
537 }
538 }
539
540 void update_file_flags(const unsigned char *sha,
541 unsigned mode,
542 const char *path,
543 int update_cache,
544 int update_wd)
545 {
546 if (index_only)
547 update_wd = 0;
548
549 if (update_wd) {
550 char type[20];
551 void *buf;
552 unsigned long size;
553
554 buf = read_sha1_file(sha, type, &size);
555 if (!buf)
556 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
557 if (strcmp(type, blob_type) != 0)
558 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
559
560 if (S_ISREG(mode)) {
561 int fd;
562 if (mkdir_p(path, 0777))
563 die("failed to create path %s: %s", path, strerror(errno));
564 unlink(path);
565 if (mode & 0100)
566 mode = 0777;
567 else
568 mode = 0666;
569 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
570 if (fd < 0)
571 die("failed to open %s: %s", path, strerror(errno));
572 flush_buffer(fd, buf, size);
573 close(fd);
574 } else if (S_ISLNK(mode)) {
575 char *lnk = xmalloc(size + 1);
576 memcpy(lnk, buf, size);
577 lnk[size] = '\0';
578 mkdir_p(path, 0777);
579 unlink(lnk);
580 symlink(lnk, path);
581 } else
582 die("do not know what to do with %06o %s '%s'",
583 mode, sha1_to_hex(sha), path);
584 }
585 if (update_cache)
586 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
587 }
588
589 void update_file(int clean,
590 const unsigned char *sha,
591 unsigned mode,
592 const char *path)
593 {
594 update_file_flags(sha, mode, path, index_only || clean, !index_only);
595 }
596
597 /* Low level file merging, update and removal */
598
599 struct merge_file_info
600 {
601 unsigned char sha[20];
602 unsigned mode;
603 unsigned clean:1,
604 merge:1;
605 };
606
607 static char *git_unpack_file(const unsigned char *sha1, char *path)
608 {
609 void *buf;
610 char type[20];
611 unsigned long size;
612 int fd;
613
614 buf = read_sha1_file(sha1, type, &size);
615 if (!buf || strcmp(type, blob_type))
616 die("unable to read blob object %s", sha1_to_hex(sha1));
617
618 strcpy(path, ".merge_file_XXXXXX");
619 fd = mkstemp(path);
620 if (fd < 0)
621 die("unable to create temp-file");
622 flush_buffer(fd, buf, size);
623 close(fd);
624 return path;
625 }
626
627 static struct merge_file_info merge_file(struct diff_filespec *o,
628 struct diff_filespec *a, struct diff_filespec *b,
629 const char *branch1, 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, o->sha1) && !sha_eq(b->sha1, o->sha1))
646 result.merge = 1;
647
648 result.mode = a->mode == o->mode ? b->mode: a->mode;
649
650 if (sha_eq(a->sha1, o->sha1))
651 hashcpy(result.sha, b->sha1);
652 else if (sha_eq(b->sha1, o->sha1))
653 hashcpy(result.sha, a->sha1);
654 else if (S_ISREG(a->mode)) {
655 int code = 1, fd;
656 struct stat st;
657 char orig[PATH_MAX];
658 char src1[PATH_MAX];
659 char src2[PATH_MAX];
660 const char *argv[] = {
661 "merge", "-L", NULL, "-L", NULL, "-L", NULL,
662 NULL, NULL, NULL,
663 NULL
664 };
665 char *la, *lb, *lo;
666
667 git_unpack_file(o->sha1, orig);
668 git_unpack_file(a->sha1, src1);
669 git_unpack_file(b->sha1, src2);
670
671 argv[2] = la = xstrdup(mkpath("%s/%s", branch1, a->path));
672 argv[6] = lb = xstrdup(mkpath("%s/%s", branch2, b->path));
673 argv[4] = lo = xstrdup(mkpath("orig/%s", o->path));
674 argv[7] = src1;
675 argv[8] = orig;
676 argv[9] = src2,
677
678 code = run_command_v(10, argv);
679
680 free(la);
681 free(lb);
682 free(lo);
683 if (code && code < -256) {
684 die("Failed to execute 'merge'. merge(1) is used as the "
685 "file-level merge tool. Is 'merge' in your path?");
686 }
687 fd = open(src1, O_RDONLY);
688 if (fd < 0 || fstat(fd, &st) < 0 ||
689 index_fd(result.sha, fd, &st, 1,
690 "blob"))
691 die("Unable to add %s to database", src1);
692
693 unlink(orig);
694 unlink(src1);
695 unlink(src2);
696
697 result.clean = WEXITSTATUS(code) == 0;
698 } else {
699 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
700 die("cannot merge modes?");
701
702 hashcpy(result.sha, a->sha1);
703
704 if (!sha_eq(a->sha1, b->sha1))
705 result.clean = 0;
706 }
707 }
708
709 return result;
710 }
711
712 static void conflict_rename_rename(struct rename *ren1,
713 const char *branch1,
714 struct rename *ren2,
715 const char *branch2)
716 {
717 char *del[2];
718 int delp = 0;
719 const char *ren1_dst = ren1->pair->two->path;
720 const char *ren2_dst = ren2->pair->two->path;
721 const char *dst_name1 = ren1_dst;
722 const char *dst_name2 = ren2_dst;
723 if (path_list_has_path(&current_directory_set, ren1_dst)) {
724 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
725 output("%s is a directory in %s adding as %s instead",
726 ren1_dst, branch2, dst_name1);
727 remove_file(0, ren1_dst);
728 }
729 if (path_list_has_path(&current_directory_set, ren2_dst)) {
730 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
731 output("%s is a directory in %s adding as %s instead",
732 ren2_dst, branch1, dst_name2);
733 remove_file(0, ren2_dst);
734 }
735 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
736 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
737 while (delp--)
738 free(del[delp]);
739 }
740
741 static void conflict_rename_dir(struct rename *ren1,
742 const char *branch1)
743 {
744 char *new_path = unique_path(ren1->pair->two->path, branch1);
745 output("Renaming %s to %s instead", ren1->pair->one->path, new_path);
746 remove_file(0, ren1->pair->two->path);
747 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
748 free(new_path);
749 }
750
751 static void conflict_rename_rename_2(struct rename *ren1,
752 const char *branch1,
753 struct rename *ren2,
754 const char *branch2)
755 {
756 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
757 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
758 output("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(0, ren1->pair->two->path);
762 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
763 update_file(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 path_list *a_renames,
769 struct path_list *b_renames,
770 const char *a_branch,
771 const char *b_branch)
772 {
773 int clean_merge = 1, i, j;
774 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
775 const struct rename *sre;
776
777 for (i = 0; i < a_renames->nr; i++) {
778 sre = a_renames->items[i].util;
779 path_list_insert(sre->pair->two->path, &a_by_dst)->util
780 = sre->dst_entry;
781 }
782 for (i = 0; i < b_renames->nr; i++) {
783 sre = b_renames->items[i].util;
784 path_list_insert(sre->pair->two->path, &b_by_dst)->util
785 = sre->dst_entry;
786 }
787
788 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
789 int compare;
790 char *src;
791 struct path_list *renames1, *renames2, *renames2Dst;
792 struct rename *ren1 = NULL, *ren2 = NULL;
793 const char *branch1, *branch2;
794 const char *ren1_src, *ren1_dst;
795
796 if (i >= a_renames->nr) {
797 compare = 1;
798 ren2 = b_renames->items[j++].util;
799 } else if (j >= b_renames->nr) {
800 compare = -1;
801 ren1 = a_renames->items[i++].util;
802 } else {
803 compare = strcmp(a_renames->items[i].path,
804 b_renames->items[j].path);
805 if (compare <= 0)
806 ren1 = a_renames->items[i++].util;
807 if (compare >= 0)
808 ren2 = b_renames->items[j++].util;
809 }
810
811 /* TODO: refactor, so that 1/2 are not needed */
812 if (ren1) {
813 renames1 = a_renames;
814 renames2 = b_renames;
815 renames2Dst = &b_by_dst;
816 branch1 = a_branch;
817 branch2 = b_branch;
818 } else {
819 struct rename *tmp;
820 renames1 = b_renames;
821 renames2 = a_renames;
822 renames2Dst = &a_by_dst;
823 branch1 = b_branch;
824 branch2 = a_branch;
825 tmp = ren2;
826 ren2 = ren1;
827 ren1 = tmp;
828 }
829 src = ren1->pair->one->path;
830
831 ren1->dst_entry->processed = 1;
832 ren1->src_entry->processed = 1;
833
834 if (ren1->processed)
835 continue;
836 ren1->processed = 1;
837
838 ren1_src = ren1->pair->one->path;
839 ren1_dst = ren1->pair->two->path;
840
841 if (ren2) {
842 const char *ren2_src = ren2->pair->one->path;
843 const char *ren2_dst = ren2->pair->two->path;
844 /* Renamed in 1 and renamed in 2 */
845 if (strcmp(ren1_src, ren2_src) != 0)
846 die("ren1.src != ren2.src");
847 ren2->dst_entry->processed = 1;
848 ren2->processed = 1;
849 if (strcmp(ren1_dst, ren2_dst) != 0) {
850 clean_merge = 0;
851 output("CONFLICT (rename/rename): "
852 "Rename %s->%s in branch %s "
853 "rename %s->%s in %s",
854 src, ren1_dst, branch1,
855 src, ren2_dst, branch2);
856 conflict_rename_rename(ren1, branch1, ren2, branch2);
857 } else {
858 struct merge_file_info mfi;
859 remove_file(1, ren1_src);
860 mfi = merge_file(ren1->pair->one,
861 ren1->pair->two,
862 ren2->pair->two,
863 branch1,
864 branch2);
865 if (mfi.merge || !mfi.clean)
866 output("Renaming %s->%s", src, ren1_dst);
867
868 if (mfi.merge)
869 output("Auto-merging %s", ren1_dst);
870
871 if (!mfi.clean) {
872 output("CONFLICT (content): merge conflict in %s",
873 ren1_dst);
874 clean_merge = 0;
875
876 if (!index_only)
877 update_stages(ren1_dst,
878 ren1->pair->one,
879 ren1->pair->two,
880 ren2->pair->two,
881 1 /* clear */);
882 }
883 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
884 }
885 } else {
886 /* Renamed in 1, maybe changed in 2 */
887 struct path_list_item *item;
888 /* we only use sha1 and mode of these */
889 struct diff_filespec src_other, dst_other;
890 int try_merge, stage = a_renames == renames1 ? 3: 2;
891
892 remove_file(1, ren1_src);
893
894 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
895 src_other.mode = ren1->src_entry->stages[stage].mode;
896 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
897 dst_other.mode = ren1->dst_entry->stages[stage].mode;
898
899 try_merge = 0;
900
901 if (path_list_has_path(&current_directory_set, ren1_dst)) {
902 clean_merge = 0;
903 output("CONFLICT (rename/directory): Rename %s->%s in %s "
904 " directory %s added in %s",
905 ren1_src, ren1_dst, branch1,
906 ren1_dst, branch2);
907 conflict_rename_dir(ren1, branch1);
908 } else if (sha_eq(src_other.sha1, null_sha1)) {
909 clean_merge = 0;
910 output("CONFLICT (rename/delete): Rename %s->%s in %s "
911 "and deleted in %s",
912 ren1_src, ren1_dst, branch1,
913 branch2);
914 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
915 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
916 const char *new_path;
917 clean_merge = 0;
918 try_merge = 1;
919 output("CONFLICT (rename/add): Rename %s->%s in %s. "
920 "%s added in %s",
921 ren1_src, ren1_dst, branch1,
922 ren1_dst, branch2);
923 new_path = unique_path(ren1_dst, branch2);
924 output("Adding as %s instead", new_path);
925 update_file(0, dst_other.sha1, dst_other.mode, new_path);
926 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
927 ren2 = item->util;
928 clean_merge = 0;
929 ren2->processed = 1;
930 output("CONFLICT (rename/rename): Rename %s->%s in %s. "
931 "Rename %s->%s in %s",
932 ren1_src, ren1_dst, branch1,
933 ren2->pair->one->path, ren2->pair->two->path, branch2);
934 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
935 } else
936 try_merge = 1;
937
938 if (try_merge) {
939 struct diff_filespec *o, *a, *b;
940 struct merge_file_info mfi;
941 src_other.path = (char *)ren1_src;
942
943 o = ren1->pair->one;
944 if (a_renames == renames1) {
945 a = ren1->pair->two;
946 b = &src_other;
947 } else {
948 b = ren1->pair->two;
949 a = &src_other;
950 }
951 mfi = merge_file(o, a, b,
952 a_branch, b_branch);
953
954 if (mfi.merge || !mfi.clean)
955 output("Renaming %s => %s", ren1_src, ren1_dst);
956 if (mfi.merge)
957 output("Auto-merging %s", ren1_dst);
958 if (!mfi.clean) {
959 output("CONFLICT (rename/modify): Merge conflict in %s",
960 ren1_dst);
961 clean_merge = 0;
962
963 if (!index_only)
964 update_stages(ren1_dst,
965 o, a, b, 1);
966 }
967 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
968 }
969 }
970 }
971 path_list_clear(&a_by_dst, 0);
972 path_list_clear(&b_by_dst, 0);
973
974 if (cache_dirty)
975 flush_cache();
976 return clean_merge;
977 }
978
979 static unsigned char *has_sha(const unsigned char *sha)
980 {
981 return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
982 }
983
984 /* Per entry merge function */
985 static int process_entry(const char *path, struct stage_data *entry,
986 const char *branch1,
987 const char *branch2)
988 {
989 /*
990 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
991 print_index_entry("\tpath: ", entry);
992 */
993 int clean_merge = 1;
994 unsigned char *o_sha = has_sha(entry->stages[1].sha);
995 unsigned char *a_sha = has_sha(entry->stages[2].sha);
996 unsigned char *b_sha = has_sha(entry->stages[3].sha);
997 unsigned o_mode = entry->stages[1].mode;
998 unsigned a_mode = entry->stages[2].mode;
999 unsigned b_mode = entry->stages[3].mode;
1000
1001 if (o_sha && (!a_sha || !b_sha)) {
1002 /* Case A: Deleted in one */
1003 if ((!a_sha && !b_sha) ||
1004 (sha_eq(a_sha, o_sha) && !b_sha) ||
1005 (!a_sha && sha_eq(b_sha, o_sha))) {
1006 /* Deleted in both or deleted in one and
1007 * unchanged in the other */
1008 if (a_sha)
1009 output("Removing %s", path);
1010 remove_file(1, path);
1011 } else {
1012 /* Deleted in one and changed in the other */
1013 clean_merge = 0;
1014 if (!a_sha) {
1015 output("CONFLICT (delete/modify): %s deleted in %s "
1016 "and modified in %s. Version %s of %s left in tree.",
1017 path, branch1,
1018 branch2, branch2, path);
1019 update_file(0, b_sha, b_mode, path);
1020 } else {
1021 output("CONFLICT (delete/modify): %s deleted in %s "
1022 "and modified in %s. Version %s of %s left in tree.",
1023 path, branch2,
1024 branch1, branch1, path);
1025 update_file(0, a_sha, a_mode, path);
1026 }
1027 }
1028
1029 } else if ((!o_sha && a_sha && !b_sha) ||
1030 (!o_sha && !a_sha && b_sha)) {
1031 /* Case B: Added in one. */
1032 const char *add_branch;
1033 const char *other_branch;
1034 unsigned mode;
1035 const unsigned char *sha;
1036 const char *conf;
1037
1038 if (a_sha) {
1039 add_branch = branch1;
1040 other_branch = branch2;
1041 mode = a_mode;
1042 sha = a_sha;
1043 conf = "file/directory";
1044 } else {
1045 add_branch = branch2;
1046 other_branch = branch1;
1047 mode = b_mode;
1048 sha = b_sha;
1049 conf = "directory/file";
1050 }
1051 if (path_list_has_path(&current_directory_set, path)) {
1052 const char *new_path = unique_path(path, add_branch);
1053 clean_merge = 0;
1054 output("CONFLICT (%s): There is a directory with name %s in %s. "
1055 "Adding %s as %s",
1056 conf, path, other_branch, path, new_path);
1057 remove_file(0, path);
1058 update_file(0, sha, mode, new_path);
1059 } else {
1060 output("Adding %s", path);
1061 update_file(1, sha, mode, path);
1062 }
1063 } else if (!o_sha && a_sha && b_sha) {
1064 /* Case C: Added in both (check for same permissions). */
1065 if (sha_eq(a_sha, b_sha)) {
1066 if (a_mode != b_mode) {
1067 clean_merge = 0;
1068 output("CONFLICT: File %s added identically in both branches, "
1069 "but permissions conflict %06o->%06o",
1070 path, a_mode, b_mode);
1071 output("CONFLICT: adding with permission: %06o", a_mode);
1072 update_file(0, a_sha, a_mode, path);
1073 } else {
1074 /* This case is handled by git-read-tree */
1075 assert(0 && "This case must be handled by git-read-tree");
1076 }
1077 } else {
1078 const char *new_path1, *new_path2;
1079 clean_merge = 0;
1080 new_path1 = unique_path(path, branch1);
1081 new_path2 = unique_path(path, branch2);
1082 output("CONFLICT (add/add): File %s added non-identically "
1083 "in both branches. Adding as %s and %s instead.",
1084 path, new_path1, new_path2);
1085 remove_file(0, path);
1086 update_file(0, a_sha, a_mode, new_path1);
1087 update_file(0, b_sha, b_mode, new_path2);
1088 }
1089
1090 } else if (o_sha && a_sha && b_sha) {
1091 /* case D: Modified in both, but differently. */
1092 struct merge_file_info mfi;
1093 struct diff_filespec o, a, b;
1094
1095 output("Auto-merging %s", path);
1096 o.path = a.path = b.path = (char *)path;
1097 hashcpy(o.sha1, o_sha);
1098 o.mode = o_mode;
1099 hashcpy(a.sha1, a_sha);
1100 a.mode = a_mode;
1101 hashcpy(b.sha1, b_sha);
1102 b.mode = b_mode;
1103
1104 mfi = merge_file(&o, &a, &b,
1105 branch1, branch2);
1106
1107 if (mfi.clean)
1108 update_file(1, mfi.sha, mfi.mode, path);
1109 else {
1110 clean_merge = 0;
1111 output("CONFLICT (content): Merge conflict in %s", path);
1112
1113 if (index_only)
1114 update_file(0, mfi.sha, mfi.mode, path);
1115 else
1116 update_file_flags(mfi.sha, mfi.mode, path,
1117 0 /* update_cache */, 1 /* update_working_directory */);
1118 }
1119 } else
1120 die("Fatal merge failure, shouldn't happen.");
1121
1122 if (cache_dirty)
1123 flush_cache();
1124
1125 return clean_merge;
1126 }
1127
1128 static int merge_trees(struct tree *head,
1129 struct tree *merge,
1130 struct tree *common,
1131 const char *branch1,
1132 const char *branch2,
1133 struct tree **result)
1134 {
1135 int code, clean;
1136 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1137 output("Already uptodate!");
1138 *result = head;
1139 return 1;
1140 }
1141
1142 code = git_merge_trees(index_only, common, head, merge);
1143
1144 if (code != 0)
1145 die("merging of trees %s and %s failed",
1146 sha1_to_hex(head->object.sha1),
1147 sha1_to_hex(merge->object.sha1));
1148
1149 *result = git_write_tree();
1150
1151 if (!*result) {
1152 struct path_list *entries, *re_head, *re_merge;
1153 int i;
1154 path_list_clear(&current_file_set, 1);
1155 path_list_clear(&current_directory_set, 1);
1156 get_files_dirs(head);
1157 get_files_dirs(merge);
1158
1159 entries = get_unmerged();
1160 re_head = get_renames(head, common, head, merge, entries);
1161 re_merge = get_renames(merge, common, head, merge, entries);
1162 clean = process_renames(re_head, re_merge,
1163 branch1, branch2);
1164 for (i = 0; i < entries->nr; i++) {
1165 const char *path = entries->items[i].path;
1166 struct stage_data *e = entries->items[i].util;
1167 if (e->processed)
1168 continue;
1169 if (!process_entry(path, e, branch1, branch2))
1170 clean = 0;
1171 }
1172
1173 path_list_clear(re_merge, 0);
1174 path_list_clear(re_head, 0);
1175 path_list_clear(entries, 1);
1176
1177 if (clean || index_only)
1178 *result = git_write_tree();
1179 else
1180 *result = NULL;
1181 } else {
1182 clean = 1;
1183 printf("merging of trees %s and %s resulted in %s\n",
1184 sha1_to_hex(head->object.sha1),
1185 sha1_to_hex(merge->object.sha1),
1186 sha1_to_hex((*result)->object.sha1));
1187 }
1188
1189 return clean;
1190 }
1191
1192 static struct commit_list *reverse_commit_list(struct commit_list *list)
1193 {
1194 struct commit_list *next = NULL, *current, *backup;
1195 for (current = list; current; current = backup) {
1196 backup = current->next;
1197 current->next = next;
1198 next = current;
1199 }
1200 return next;
1201 }
1202
1203 /*
1204 * Merge the commits h1 and h2, return the resulting virtual
1205 * commit object and a flag indicating the cleaness of the merge.
1206 */
1207 static
1208 int merge(struct commit *h1,
1209 struct commit *h2,
1210 const char *branch1,
1211 const char *branch2,
1212 int call_depth /* =0 */,
1213 struct commit *ancestor /* =None */,
1214 struct commit **result)
1215 {
1216 struct commit_list *ca = NULL, *iter;
1217 struct commit *merged_common_ancestors;
1218 struct tree *mrtree;
1219 int clean;
1220
1221 output("Merging:");
1222 output_commit_title(h1);
1223 output_commit_title(h2);
1224
1225 if (ancestor)
1226 commit_list_insert(ancestor, &ca);
1227 else
1228 ca = reverse_commit_list(get_merge_bases(h1, h2, 1));
1229
1230 output("found %u common ancestor(s):", commit_list_count(ca));
1231 for (iter = ca; iter; iter = iter->next)
1232 output_commit_title(iter->item);
1233
1234 merged_common_ancestors = pop_commit(&ca);
1235 if (merged_common_ancestors == NULL) {
1236 /* if there is no common ancestor, make an empty tree */
1237 struct tree *tree = xcalloc(1, sizeof(struct tree));
1238 unsigned char hdr[40];
1239 int hdrlen;
1240
1241 tree->object.parsed = 1;
1242 tree->object.type = OBJ_TREE;
1243 write_sha1_file_prepare(NULL, 0, tree_type, tree->object.sha1,
1244 hdr, &hdrlen);
1245 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1246 }
1247
1248 for (iter = ca; iter; iter = iter->next) {
1249 output_indent = call_depth + 1;
1250 /*
1251 * When the merge fails, the result contains files
1252 * with conflict markers. The cleanness flag is
1253 * ignored, it was never acutally used, as result of
1254 * merge_trees has always overwritten it: the commited
1255 * "conflicts" were already resolved.
1256 */
1257 merge(merged_common_ancestors, iter->item,
1258 "Temporary merge branch 1",
1259 "Temporary merge branch 2",
1260 call_depth + 1,
1261 NULL,
1262 &merged_common_ancestors);
1263 output_indent = call_depth;
1264
1265 if (!merged_common_ancestors)
1266 die("merge returned no commit");
1267 }
1268
1269 if (call_depth == 0) {
1270 setup_index(0 /* $GIT_DIR/index */);
1271 index_only = 0;
1272 } else {
1273 setup_index(1 /* temporary index */);
1274 git_read_tree(h1->tree);
1275 index_only = 1;
1276 }
1277
1278 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1279 branch1, branch2, &mrtree);
1280
1281 if (!ancestor && (clean || index_only)) {
1282 *result = make_virtual_commit(mrtree, "merged tree");
1283 commit_list_insert(h1, &(*result)->parents);
1284 commit_list_insert(h2, &(*result)->parents->next);
1285 } else
1286 *result = NULL;
1287
1288 return clean;
1289 }
1290
1291 static struct commit *get_ref(const char *ref)
1292 {
1293 unsigned char sha1[20];
1294 struct object *object;
1295
1296 if (get_sha1(ref, sha1))
1297 die("Could not resolve ref '%s'", ref);
1298 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1299 if (object->type != OBJ_COMMIT)
1300 return NULL;
1301 if (parse_commit((struct commit *)object))
1302 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1303 return (struct commit *)object;
1304 }
1305
1306 int main(int argc, char *argv[])
1307 {
1308 static const char *bases[2];
1309 static unsigned bases_count = 0;
1310 int i, clean;
1311 const char *branch1, *branch2;
1312 struct commit *result, *h1, *h2;
1313
1314 original_index_file = getenv("GIT_INDEX_FILE");
1315
1316 if (!original_index_file)
1317 original_index_file = xstrdup(git_path("index"));
1318
1319 temporary_index_file = xstrdup(git_path("mrg-rcrsv-tmp-idx"));
1320
1321 if (argc < 4)
1322 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1323
1324 for (i = 1; i < argc; ++i) {
1325 if (!strcmp(argv[i], "--"))
1326 break;
1327 if (bases_count < sizeof(bases)/sizeof(*bases))
1328 bases[bases_count++] = argv[i];
1329 }
1330 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1331 die("Not handling anything other than two heads merge.");
1332
1333 branch1 = argv[++i];
1334 branch2 = argv[++i];
1335 printf("Merging %s with %s\n", branch1, branch2);
1336
1337 h1 = get_ref(branch1);
1338 h2 = get_ref(branch2);
1339
1340 if (bases_count == 1) {
1341 struct commit *ancestor = get_ref(bases[0]);
1342 clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
1343 } else
1344 clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
1345
1346 if (cache_dirty)
1347 flush_cache();
1348
1349 return clean ? 0: 1;
1350 }
1351
1352 /*
1353 vim: sw=8 noet
1354 */
git for Debian