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merge-recursive: do not rudely die on binary merge
[git/builtin-gsoc.git] / merge-recursive.c
blob5326d7c97a693e409de2cbb406e08dd9fac77577
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 #include "interpolate.h"
19 #include "attr.h"
20
21 static int subtree_merge;
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
39 * - (const char *)commit->util set to the name, and
40 * - *(int *)commit->object.sha1 set to the virtual id.
41 */
42
43 static unsigned commit_list_count(const struct commit_list *l)
44 {
45 unsigned c = 0;
46 for (; l; l = l->next )
47 c++;
48 return c;
49 }
50
51 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
52 {
53 struct commit *commit = xcalloc(1, sizeof(struct commit));
54 static unsigned virtual_id = 1;
55 commit->tree = tree;
56 commit->util = (void*)comment;
57 *(int*)commit->object.sha1 = virtual_id++;
58 /* avoid warnings */
59 commit->object.parsed = 1;
60 return commit;
61 }
62
63 /*
64 * Since we use get_tree_entry(), which does not put the read object into
65 * the object pool, we cannot rely on a == b.
66 */
67 static int sha_eq(const unsigned char *a, const unsigned char *b)
68 {
69 if (!a && !b)
70 return 2;
71 return a && b && hashcmp(a, b) == 0;
72 }
73
74 /*
75 * Since we want to write the index eventually, we cannot reuse the index
76 * for these (temporary) data.
77 */
78 struct stage_data
79 {
80 struct
81 {
82 unsigned mode;
83 unsigned char sha[20];
84 } stages[4];
85 unsigned processed:1;
86 };
87
88 struct output_buffer
89 {
90 struct output_buffer *next;
91 char *str;
92 };
93
94 static struct path_list current_file_set = {NULL, 0, 0, 1};
95 static struct path_list current_directory_set = {NULL, 0, 0, 1};
96
97 static int call_depth = 0;
98 static int verbosity = 2;
99 static int buffer_output = 1;
100 static struct output_buffer *output_list, *output_end;
101
102 static int show (int v)
103 {
104 return (!call_depth && verbosity >= v) || verbosity >= 5;
105 }
106
107 static void output(int v, const char *fmt, ...)
108 {
109 va_list args;
110 va_start(args, fmt);
111 if (buffer_output && show(v)) {
112 struct output_buffer *b = xmalloc(sizeof(*b));
113 nfvasprintf(&b->str, fmt, args);
114 b->next = NULL;
115 if (output_end)
116 output_end->next = b;
117 else
118 output_list = b;
119 output_end = b;
120 } else if (show(v)) {
121 int i;
122 for (i = call_depth; i--;)
123 fputs(" ", stdout);
124 vfprintf(stdout, fmt, args);
125 fputc('\n', stdout);
126 }
127 va_end(args);
128 }
129
130 static void flush_output(void)
131 {
132 struct output_buffer *b, *n;
133 for (b = output_list; b; b = n) {
134 int i;
135 for (i = call_depth; i--;)
136 fputs(" ", stdout);
137 fputs(b->str, stdout);
138 fputc('\n', stdout);
139 n = b->next;
140 free(b->str);
141 free(b);
142 }
143 output_list = NULL;
144 output_end = NULL;
145 }
146
147 static void output_commit_title(struct commit *commit)
148 {
149 int i;
150 flush_output();
151 for (i = call_depth; i--;)
152 fputs(" ", stdout);
153 if (commit->util)
154 printf("virtual %s\n", (char *)commit->util);
155 else {
156 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
157 if (parse_commit(commit) != 0)
158 printf("(bad commit)\n");
159 else {
160 const char *s;
161 int len;
162 for (s = commit->buffer; *s; s++)
163 if (*s == '\n' && s[1] == '\n') {
164 s += 2;
165 break;
166 }
167 for (len = 0; s[len] && '\n' != s[len]; len++)
168 ; /* do nothing */
169 printf("%.*s\n", len, s);
170 }
171 }
172 }
173
174 static struct cache_entry *make_cache_entry(unsigned int mode,
175 const unsigned char *sha1, const char *path, int stage, int refresh)
176 {
177 int size, len;
178 struct cache_entry *ce;
179
180 if (!verify_path(path))
181 return NULL;
182
183 len = strlen(path);
184 size = cache_entry_size(len);
185 ce = xcalloc(1, size);
186
187 hashcpy(ce->sha1, sha1);
188 memcpy(ce->name, path, len);
189 ce->ce_flags = create_ce_flags(len, stage);
190 ce->ce_mode = create_ce_mode(mode);
191
192 if (refresh)
193 return refresh_cache_entry(ce, 0);
194
195 return ce;
196 }
197
198 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
199 const char *path, int stage, int refresh, int options)
200 {
201 struct cache_entry *ce;
202 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
203 if (!ce)
204 return error("addinfo_cache failed for path '%s'", path);
205 return add_cache_entry(ce, options);
206 }
207
208 /*
209 * This is a global variable which is used in a number of places but
210 * only written to in the 'merge' function.
211 *
212 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
213 * don't update the working directory.
214 * 0 => Leave unmerged entries in the cache and update
215 * the working directory.
216 */
217 static int index_only = 0;
218
219 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
220 {
221 parse_tree(tree);
222 init_tree_desc(desc, tree->buffer, tree->size);
223 }
224
225 static int git_merge_trees(int index_only,
226 struct tree *common,
227 struct tree *head,
228 struct tree *merge)
229 {
230 int rc;
231 struct tree_desc t[3];
232 struct unpack_trees_options opts;
233
234 memset(&opts, 0, sizeof(opts));
235 if (index_only)
236 opts.index_only = 1;
237 else
238 opts.update = 1;
239 opts.merge = 1;
240 opts.head_idx = 2;
241 opts.fn = threeway_merge;
242
243 init_tree_desc_from_tree(t+0, common);
244 init_tree_desc_from_tree(t+1, head);
245 init_tree_desc_from_tree(t+2, merge);
246
247 rc = unpack_trees(3, t, &opts);
248 cache_tree_free(&active_cache_tree);
249 return rc;
250 }
251
252 static int unmerged_index(void)
253 {
254 int i;
255 for (i = 0; i < active_nr; i++) {
256 struct cache_entry *ce = active_cache[i];
257 if (ce_stage(ce))
258 return 1;
259 }
260 return 0;
261 }
262
263 static struct tree *git_write_tree(void)
264 {
265 struct tree *result = NULL;
266
267 if (unmerged_index()) {
268 int i;
269 output(0, "There are unmerged index entries:");
270 for (i = 0; i < active_nr; i++) {
271 struct cache_entry *ce = active_cache[i];
272 if (ce_stage(ce))
273 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
274 }
275 return NULL;
276 }
277
278 if (!active_cache_tree)
279 active_cache_tree = cache_tree();
280
281 if (!cache_tree_fully_valid(active_cache_tree) &&
282 cache_tree_update(active_cache_tree,
283 active_cache, active_nr, 0, 0) < 0)
284 die("error building trees");
285
286 result = lookup_tree(active_cache_tree->sha1);
287
288 return result;
289 }
290
291 static int save_files_dirs(const unsigned char *sha1,
292 const char *base, int baselen, const char *path,
293 unsigned int mode, int stage)
294 {
295 int len = strlen(path);
296 char *newpath = xmalloc(baselen + len + 1);
297 memcpy(newpath, base, baselen);
298 memcpy(newpath + baselen, path, len);
299 newpath[baselen + len] = '\0';
300
301 if (S_ISDIR(mode))
302 path_list_insert(newpath, &current_directory_set);
303 else
304 path_list_insert(newpath, &current_file_set);
305 free(newpath);
306
307 return READ_TREE_RECURSIVE;
308 }
309
310 static int get_files_dirs(struct tree *tree)
311 {
312 int n;
313 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
314 return 0;
315 n = current_file_set.nr + current_directory_set.nr;
316 return n;
317 }
318
319 /*
320 * Returns a index_entry instance which doesn't have to correspond to
321 * a real cache entry in Git's index.
322 */
323 static struct stage_data *insert_stage_data(const char *path,
324 struct tree *o, struct tree *a, struct tree *b,
325 struct path_list *entries)
326 {
327 struct path_list_item *item;
328 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
329 get_tree_entry(o->object.sha1, path,
330 e->stages[1].sha, &e->stages[1].mode);
331 get_tree_entry(a->object.sha1, path,
332 e->stages[2].sha, &e->stages[2].mode);
333 get_tree_entry(b->object.sha1, path,
334 e->stages[3].sha, &e->stages[3].mode);
335 item = path_list_insert(path, entries);
336 item->util = e;
337 return e;
338 }
339
340 /*
341 * Create a dictionary mapping file names to stage_data objects. The
342 * dictionary contains one entry for every path with a non-zero stage entry.
343 */
344 static struct path_list *get_unmerged(void)
345 {
346 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
347 int i;
348
349 unmerged->strdup_paths = 1;
350
351 for (i = 0; i < active_nr; i++) {
352 struct path_list_item *item;
353 struct stage_data *e;
354 struct cache_entry *ce = active_cache[i];
355 if (!ce_stage(ce))
356 continue;
357
358 item = path_list_lookup(ce->name, unmerged);
359 if (!item) {
360 item = path_list_insert(ce->name, unmerged);
361 item->util = xcalloc(1, sizeof(struct stage_data));
362 }
363 e = item->util;
364 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
365 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
366 }
367
368 return unmerged;
369 }
370
371 struct rename
372 {
373 struct diff_filepair *pair;
374 struct stage_data *src_entry;
375 struct stage_data *dst_entry;
376 unsigned processed:1;
377 };
378
379 /*
380 * Get information of all renames which occurred between 'o_tree' and
381 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
382 * 'b_tree') to be able to associate the correct cache entries with
383 * the rename information. 'tree' is always equal to either a_tree or b_tree.
384 */
385 static struct path_list *get_renames(struct tree *tree,
386 struct tree *o_tree,
387 struct tree *a_tree,
388 struct tree *b_tree,
389 struct path_list *entries)
390 {
391 int i;
392 struct path_list *renames;
393 struct diff_options opts;
394
395 renames = xcalloc(1, sizeof(struct path_list));
396 diff_setup(&opts);
397 opts.recursive = 1;
398 opts.detect_rename = DIFF_DETECT_RENAME;
399 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
400 if (diff_setup_done(&opts) < 0)
401 die("diff setup failed");
402 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
403 diffcore_std(&opts);
404 for (i = 0; i < diff_queued_diff.nr; ++i) {
405 struct path_list_item *item;
406 struct rename *re;
407 struct diff_filepair *pair = diff_queued_diff.queue[i];
408 if (pair->status != 'R') {
409 diff_free_filepair(pair);
410 continue;
411 }
412 re = xmalloc(sizeof(*re));
413 re->processed = 0;
414 re->pair = pair;
415 item = path_list_lookup(re->pair->one->path, entries);
416 if (!item)
417 re->src_entry = insert_stage_data(re->pair->one->path,
418 o_tree, a_tree, b_tree, entries);
419 else
420 re->src_entry = item->util;
421
422 item = path_list_lookup(re->pair->two->path, entries);
423 if (!item)
424 re->dst_entry = insert_stage_data(re->pair->two->path,
425 o_tree, a_tree, b_tree, entries);
426 else
427 re->dst_entry = item->util;
428 item = path_list_insert(pair->one->path, renames);
429 item->util = re;
430 }
431 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
432 diff_queued_diff.nr = 0;
433 diff_flush(&opts);
434 return renames;
435 }
436
437 static int update_stages(const char *path, struct diff_filespec *o,
438 struct diff_filespec *a, struct diff_filespec *b,
439 int clear)
440 {
441 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
442 if (clear)
443 if (remove_file_from_cache(path))
444 return -1;
445 if (o)
446 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
447 return -1;
448 if (a)
449 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
450 return -1;
451 if (b)
452 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
453 return -1;
454 return 0;
455 }
456
457 static int remove_path(const char *name)
458 {
459 int ret, len;
460 char *slash, *dirs;
461
462 ret = unlink(name);
463 if (ret)
464 return ret;
465 len = strlen(name);
466 dirs = xmalloc(len+1);
467 memcpy(dirs, name, len);
468 dirs[len] = '\0';
469 while ((slash = strrchr(name, '/'))) {
470 *slash = '\0';
471 len = slash - name;
472 if (rmdir(name) != 0)
473 break;
474 }
475 free(dirs);
476 return ret;
477 }
478
479 static int remove_file(int clean, const char *path, int no_wd)
480 {
481 int update_cache = index_only || clean;
482 int update_working_directory = !index_only && !no_wd;
483
484 if (update_cache) {
485 if (remove_file_from_cache(path))
486 return -1;
487 }
488 if (update_working_directory) {
489 unlink(path);
490 if (errno != ENOENT || errno != EISDIR)
491 return -1;
492 remove_path(path);
493 }
494 return 0;
495 }
496
497 static char *unique_path(const char *path, const char *branch)
498 {
499 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
500 int suffix = 0;
501 struct stat st;
502 char *p = newpath + strlen(path);
503 strcpy(newpath, path);
504 *(p++) = '~';
505 strcpy(p, branch);
506 for (; *p; ++p)
507 if ('/' == *p)
508 *p = '_';
509 while (path_list_has_path(&current_file_set, newpath) ||
510 path_list_has_path(&current_directory_set, newpath) ||
511 lstat(newpath, &st) == 0)
512 sprintf(p, "_%d", suffix++);
513
514 path_list_insert(newpath, &current_file_set);
515 return newpath;
516 }
517
518 static int mkdir_p(const char *path, unsigned long mode)
519 {
520 /* path points to cache entries, so xstrdup before messing with it */
521 char *buf = xstrdup(path);
522 int result = safe_create_leading_directories(buf);
523 free(buf);
524 return result;
525 }
526
527 static void flush_buffer(int fd, const char *buf, unsigned long size)
528 {
529 while (size > 0) {
530 long ret = write_in_full(fd, buf, size);
531 if (ret < 0) {
532 /* Ignore epipe */
533 if (errno == EPIPE)
534 break;
535 die("merge-recursive: %s", strerror(errno));
536 } else if (!ret) {
537 die("merge-recursive: disk full?");
538 }
539 size -= ret;
540 buf += ret;
541 }
542 }
543
544 static int make_room_for_path(const char *path)
545 {
546 int status;
547 const char *msg = "failed to create path '%s'%s";
548
549 status = mkdir_p(path, 0777);
550 if (status) {
551 if (status == -3) {
552 /* something else exists */
553 error(msg, path, ": perhaps a D/F conflict?");
554 return -1;
555 }
556 die(msg, path, "");
557 }
558
559 /* Successful unlink is good.. */
560 if (!unlink(path))
561 return 0;
562 /* .. and so is no existing file */
563 if (errno == ENOENT)
564 return 0;
565 /* .. but not some other error (who really cares what?) */
566 return error(msg, path, ": perhaps a D/F conflict?");
567 }
568
569 static void update_file_flags(const unsigned char *sha,
570 unsigned mode,
571 const char *path,
572 int update_cache,
573 int update_wd)
574 {
575 if (index_only)
576 update_wd = 0;
577
578 if (update_wd) {
579 enum object_type type;
580 void *buf;
581 unsigned long size;
582
583 buf = read_sha1_file(sha, &type, &size);
584 if (!buf)
585 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
586 if (type != OBJ_BLOB)
587 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
588
589 if (make_room_for_path(path) < 0) {
590 update_wd = 0;
591 goto update_index;
592 }
593 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
594 int fd;
595 if (mode & 0100)
596 mode = 0777;
597 else
598 mode = 0666;
599 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
600 if (fd < 0)
601 die("failed to open %s: %s", path, strerror(errno));
602 flush_buffer(fd, buf, size);
603 close(fd);
604 } else if (S_ISLNK(mode)) {
605 char *lnk = xmalloc(size + 1);
606 memcpy(lnk, buf, size);
607 lnk[size] = '\0';
608 mkdir_p(path, 0777);
609 unlink(path);
610 symlink(lnk, path);
611 free(lnk);
612 } else
613 die("do not know what to do with %06o %s '%s'",
614 mode, sha1_to_hex(sha), path);
615 }
616 update_index:
617 if (update_cache)
618 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
619 }
620
621 static void update_file(int clean,
622 const unsigned char *sha,
623 unsigned mode,
624 const char *path)
625 {
626 update_file_flags(sha, mode, path, index_only || clean, !index_only);
627 }
628
629 /* Low level file merging, update and removal */
630
631 struct merge_file_info
632 {
633 unsigned char sha[20];
634 unsigned mode;
635 unsigned clean:1,
636 merge:1;
637 };
638
639 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
640 {
641 unsigned long size;
642 enum object_type type;
643
644 if (!hashcmp(sha1, null_sha1)) {
645 mm->ptr = xstrdup("");
646 mm->size = 0;
647 return;
648 }
649
650 mm->ptr = read_sha1_file(sha1, &type, &size);
651 if (!mm->ptr || type != OBJ_BLOB)
652 die("unable to read blob object %s", sha1_to_hex(sha1));
653 mm->size = size;
654 }
655
656 /*
657 * Customizable low-level merge drivers support.
658 */
659
660 struct ll_merge_driver;
661 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
662 const char *path,
663 mmfile_t *orig,
664 mmfile_t *src1, const char *name1,
665 mmfile_t *src2, const char *name2,
666 mmbuffer_t *result);
667
668 struct ll_merge_driver {
669 const char *name;
670 const char *description;
671 ll_merge_fn fn;
672 const char *recursive;
673 struct ll_merge_driver *next;
674 char *cmdline;
675 };
676
677 /*
678 * Built-in low-levels
679 */
680 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
681 const char *path_unused,
682 mmfile_t *orig,
683 mmfile_t *src1, const char *name1,
684 mmfile_t *src2, const char *name2,
685 mmbuffer_t *result)
686 {
687 /*
688 * The tentative merge result is "ours" for the final round,
689 * or common ancestor for an internal merge. Still return
690 * "conflicted merge" status.
691 */
692 mmfile_t *stolen = index_only ? orig : src1;
693
694 result->ptr = stolen->ptr;
695 result->size = stolen->size;
696 stolen->ptr = NULL;
697 return 1;
698 }
699
700 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
701 const char *path_unused,
702 mmfile_t *orig,
703 mmfile_t *src1, const char *name1,
704 mmfile_t *src2, const char *name2,
705 mmbuffer_t *result)
706 {
707 xpparam_t xpp;
708
709 if (buffer_is_binary(orig->ptr, orig->size) ||
710 buffer_is_binary(src1->ptr, src1->size) ||
711 buffer_is_binary(src2->ptr, src2->size)) {
712 warning("Cannot merge binary files: %s vs. %s\n",
713 name1, name2);
714 return ll_binary_merge(drv_unused, path_unused,
715 orig, src1, name1,
716 src2, name2,
717 result);
718 }
719
720 memset(&xpp, 0, sizeof(xpp));
721 return xdl_merge(orig,
722 src1, name1,
723 src2, name2,
724 &xpp, XDL_MERGE_ZEALOUS,
725 result);
726 }
727
728 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
729 const char *path_unused,
730 mmfile_t *orig,
731 mmfile_t *src1, const char *name1,
732 mmfile_t *src2, const char *name2,
733 mmbuffer_t *result)
734 {
735 char *src, *dst;
736 long size;
737 const int marker_size = 7;
738
739 int status = ll_xdl_merge(drv_unused, path_unused,
740 orig, src1, NULL, src2, NULL, result);
741 if (status <= 0)
742 return status;
743 size = result->size;
744 src = dst = result->ptr;
745 while (size) {
746 char ch;
747 if ((marker_size < size) &&
748 (*src == '<' || *src == '=' || *src == '>')) {
749 int i;
750 ch = *src;
751 for (i = 0; i < marker_size; i++)
752 if (src[i] != ch)
753 goto not_a_marker;
754 if (src[marker_size] != '\n')
755 goto not_a_marker;
756 src += marker_size + 1;
757 size -= marker_size + 1;
758 continue;
759 }
760 not_a_marker:
761 do {
762 ch = *src++;
763 *dst++ = ch;
764 size--;
765 } while (ch != '\n' && size);
766 }
767 result->size = dst - result->ptr;
768 return 0;
769 }
770
771 #define LL_BINARY_MERGE 0
772 #define LL_TEXT_MERGE 1
773 #define LL_UNION_MERGE 2
774 static struct ll_merge_driver ll_merge_drv[] = {
775 { "binary", "built-in binary merge", ll_binary_merge },
776 { "text", "built-in 3-way text merge", ll_xdl_merge },
777 { "union", "built-in union merge", ll_union_merge },
778 };
779
780 static void create_temp(mmfile_t *src, char *path)
781 {
782 int fd;
783
784 strcpy(path, ".merge_file_XXXXXX");
785 fd = mkstemp(path);
786 if (fd < 0)
787 die("unable to create temp-file");
788 if (write_in_full(fd, src->ptr, src->size) != src->size)
789 die("unable to write temp-file");
790 close(fd);
791 }
792
793 /*
794 * User defined low-level merge driver support.
795 */
796 static int ll_ext_merge(const struct ll_merge_driver *fn,
797 const char *path,
798 mmfile_t *orig,
799 mmfile_t *src1, const char *name1,
800 mmfile_t *src2, const char *name2,
801 mmbuffer_t *result)
802 {
803 char temp[3][50];
804 char cmdbuf[2048];
805 struct interp table[] = {
806 { "%O" },
807 { "%A" },
808 { "%B" },
809 };
810 struct child_process child;
811 const char *args[20];
812 int status, fd, i;
813 struct stat st;
814
815 if (fn->cmdline == NULL)
816 die("custom merge driver %s lacks command line.", fn->name);
817
818 result->ptr = NULL;
819 result->size = 0;
820 create_temp(orig, temp[0]);
821 create_temp(src1, temp[1]);
822 create_temp(src2, temp[2]);
823
824 interp_set_entry(table, 0, temp[0]);
825 interp_set_entry(table, 1, temp[1]);
826 interp_set_entry(table, 2, temp[2]);
827
828 output(1, "merging %s using %s", path,
829 fn->description ? fn->description : fn->name);
830
831 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
832
833 memset(&child, 0, sizeof(child));
834 child.argv = args;
835 args[0] = "sh";
836 args[1] = "-c";
837 args[2] = cmdbuf;
838 args[3] = NULL;
839
840 status = run_command(&child);
841 if (status < -ERR_RUN_COMMAND_FORK)
842 ; /* failure in run-command */
843 else
844 status = -status;
845 fd = open(temp[1], O_RDONLY);
846 if (fd < 0)
847 goto bad;
848 if (fstat(fd, &st))
849 goto close_bad;
850 result->size = st.st_size;
851 result->ptr = xmalloc(result->size + 1);
852 if (read_in_full(fd, result->ptr, result->size) != result->size) {
853 free(result->ptr);
854 result->ptr = NULL;
855 result->size = 0;
856 }
857 close_bad:
858 close(fd);
859 bad:
860 for (i = 0; i < 3; i++)
861 unlink(temp[i]);
862 return status;
863 }
864
865 /*
866 * merge.default and merge.driver configuration items
867 */
868 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
869 static const char *default_ll_merge;
870
871 static int read_merge_config(const char *var, const char *value)
872 {
873 struct ll_merge_driver *fn;
874 const char *ep, *name;
875 int namelen;
876
877 if (!strcmp(var, "merge.default")) {
878 if (value)
879 default_ll_merge = strdup(value);
880 return 0;
881 }
882
883 /*
884 * We are not interested in anything but "merge.<name>.variable";
885 * especially, we do not want to look at variables such as
886 * "merge.summary", "merge.tool", and "merge.verbosity".
887 */
888 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
889 return 0;
890
891 /*
892 * Find existing one as we might be processing merge.<name>.var2
893 * after seeing merge.<name>.var1.
894 */
895 name = var + 6;
896 namelen = ep - name;
897 for (fn = ll_user_merge; fn; fn = fn->next)
898 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
899 break;
900 if (!fn) {
901 char *namebuf;
902 fn = xcalloc(1, sizeof(struct ll_merge_driver));
903 namebuf = xmalloc(namelen + 1);
904 memcpy(namebuf, name, namelen);
905 namebuf[namelen] = 0;
906 fn->name = namebuf;
907 fn->fn = ll_ext_merge;
908 fn->next = NULL;
909 *ll_user_merge_tail = fn;
910 ll_user_merge_tail = &(fn->next);
911 }
912
913 ep++;
914
915 if (!strcmp("name", ep)) {
916 if (!value)
917 return error("%s: lacks value", var);
918 fn->description = strdup(value);
919 return 0;
920 }
921
922 if (!strcmp("driver", ep)) {
923 if (!value)
924 return error("%s: lacks value", var);
925 /*
926 * merge.<name>.driver specifies the command line:
927 *
928 * command-line
929 *
930 * The command-line will be interpolated with the following
931 * tokens and is given to the shell:
932 *
933 * %O - temporary file name for the merge base.
934 * %A - temporary file name for our version.
935 * %B - temporary file name for the other branches' version.
936 *
937 * The external merge driver should write the results in the
938 * file named by %A, and signal that it has done with zero exit
939 * status.
940 */
941 fn->cmdline = strdup(value);
942 return 0;
943 }
944
945 if (!strcmp("recursive", ep)) {
946 if (!value)
947 return error("%s: lacks value", var);
948 fn->recursive = strdup(value);
949 return 0;
950 }
951
952 return 0;
953 }
954
955 static void initialize_ll_merge(void)
956 {
957 if (ll_user_merge_tail)
958 return;
959 ll_user_merge_tail = &ll_user_merge;
960 git_config(read_merge_config);
961 }
962
963 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
964 {
965 struct ll_merge_driver *fn;
966 const char *name;
967 int i;
968
969 initialize_ll_merge();
970
971 if (ATTR_TRUE(merge_attr))
972 return &ll_merge_drv[LL_TEXT_MERGE];
973 else if (ATTR_FALSE(merge_attr))
974 return &ll_merge_drv[LL_BINARY_MERGE];
975 else if (ATTR_UNSET(merge_attr)) {
976 if (!default_ll_merge)
977 return &ll_merge_drv[LL_TEXT_MERGE];
978 else
979 name = default_ll_merge;
980 }
981 else
982 name = merge_attr;
983
984 for (fn = ll_user_merge; fn; fn = fn->next)
985 if (!strcmp(fn->name, name))
986 return fn;
987
988 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
989 if (!strcmp(ll_merge_drv[i].name, name))
990 return &ll_merge_drv[i];
991
992 /* default to the 3-way */
993 return &ll_merge_drv[LL_TEXT_MERGE];
994 }
995
996 static const char *git_path_check_merge(const char *path)
997 {
998 static struct git_attr_check attr_merge_check;
999
1000 if (!attr_merge_check.attr)
1001 attr_merge_check.attr = git_attr("merge", 5);
1002
1003 if (git_checkattr(path, 1, &attr_merge_check))
1004 return NULL;
1005 return attr_merge_check.value;
1006 }
1007
1008 static int ll_merge(mmbuffer_t *result_buf,
1009 struct diff_filespec *o,
1010 struct diff_filespec *a,
1011 struct diff_filespec *b,
1012 const char *branch1,
1013 const char *branch2)
1014 {
1015 mmfile_t orig, src1, src2;
1016 char *name1, *name2;
1017 int merge_status;
1018 const char *ll_driver_name;
1019 const struct ll_merge_driver *driver;
1020
1021 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1022 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1023
1024 fill_mm(o->sha1, &orig);
1025 fill_mm(a->sha1, &src1);
1026 fill_mm(b->sha1, &src2);
1027
1028 ll_driver_name = git_path_check_merge(a->path);
1029 driver = find_ll_merge_driver(ll_driver_name);
1030
1031 if (index_only && driver->recursive)
1032 driver = find_ll_merge_driver(driver->recursive);
1033 merge_status = driver->fn(driver, a->path,
1034 &orig, &src1, name1, &src2, name2,
1035 result_buf);
1036
1037 free(name1);
1038 free(name2);
1039 free(orig.ptr);
1040 free(src1.ptr);
1041 free(src2.ptr);
1042 return merge_status;
1043 }
1044
1045 static struct merge_file_info merge_file(struct diff_filespec *o,
1046 struct diff_filespec *a, struct diff_filespec *b,
1047 const char *branch1, const char *branch2)
1048 {
1049 struct merge_file_info result;
1050 result.merge = 0;
1051 result.clean = 1;
1052
1053 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1054 result.clean = 0;
1055 if (S_ISREG(a->mode)) {
1056 result.mode = a->mode;
1057 hashcpy(result.sha, a->sha1);
1058 } else {
1059 result.mode = b->mode;
1060 hashcpy(result.sha, b->sha1);
1061 }
1062 } else {
1063 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1064 result.merge = 1;
1065
1066 result.mode = a->mode == o->mode ? b->mode: a->mode;
1067
1068 if (sha_eq(a->sha1, o->sha1))
1069 hashcpy(result.sha, b->sha1);
1070 else if (sha_eq(b->sha1, o->sha1))
1071 hashcpy(result.sha, a->sha1);
1072 else if (S_ISREG(a->mode)) {
1073 mmbuffer_t result_buf;
1074 int merge_status;
1075
1076 merge_status = ll_merge(&result_buf, o, a, b,
1077 branch1, branch2);
1078
1079 if ((merge_status < 0) || !result_buf.ptr)
1080 die("Failed to execute internal merge");
1081
1082 if (write_sha1_file(result_buf.ptr, result_buf.size,
1083 blob_type, result.sha))
1084 die("Unable to add %s to database",
1085 a->path);
1086
1087 free(result_buf.ptr);
1088 result.clean = (merge_status == 0);
1089 } else {
1090 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1091 die("cannot merge modes?");
1092
1093 hashcpy(result.sha, a->sha1);
1094
1095 if (!sha_eq(a->sha1, b->sha1))
1096 result.clean = 0;
1097 }
1098 }
1099
1100 return result;
1101 }
1102
1103 static void conflict_rename_rename(struct rename *ren1,
1104 const char *branch1,
1105 struct rename *ren2,
1106 const char *branch2)
1107 {
1108 char *del[2];
1109 int delp = 0;
1110 const char *ren1_dst = ren1->pair->two->path;
1111 const char *ren2_dst = ren2->pair->two->path;
1112 const char *dst_name1 = ren1_dst;
1113 const char *dst_name2 = ren2_dst;
1114 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1115 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1116 output(1, "%s is a directory in %s added as %s instead",
1117 ren1_dst, branch2, dst_name1);
1118 remove_file(0, ren1_dst, 0);
1119 }
1120 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1121 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1122 output(1, "%s is a directory in %s added as %s instead",
1123 ren2_dst, branch1, dst_name2);
1124 remove_file(0, ren2_dst, 0);
1125 }
1126 if (index_only) {
1127 remove_file_from_cache(dst_name1);
1128 remove_file_from_cache(dst_name2);
1129 /*
1130 * Uncomment to leave the conflicting names in the resulting tree
1131 *
1132 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1133 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1134 */
1135 } else {
1136 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1137 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1138 }
1139 while (delp--)
1140 free(del[delp]);
1141 }
1142
1143 static void conflict_rename_dir(struct rename *ren1,
1144 const char *branch1)
1145 {
1146 char *new_path = unique_path(ren1->pair->two->path, branch1);
1147 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1148 remove_file(0, ren1->pair->two->path, 0);
1149 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1150 free(new_path);
1151 }
1152
1153 static void conflict_rename_rename_2(struct rename *ren1,
1154 const char *branch1,
1155 struct rename *ren2,
1156 const char *branch2)
1157 {
1158 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1159 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1160 output(1, "Renamed %s to %s and %s to %s instead",
1161 ren1->pair->one->path, new_path1,
1162 ren2->pair->one->path, new_path2);
1163 remove_file(0, ren1->pair->two->path, 0);
1164 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1165 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1166 free(new_path2);
1167 free(new_path1);
1168 }
1169
1170 static int process_renames(struct path_list *a_renames,
1171 struct path_list *b_renames,
1172 const char *a_branch,
1173 const char *b_branch)
1174 {
1175 int clean_merge = 1, i, j;
1176 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1177 const struct rename *sre;
1178
1179 for (i = 0; i < a_renames->nr; i++) {
1180 sre = a_renames->items[i].util;
1181 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1182 = sre->dst_entry;
1183 }
1184 for (i = 0; i < b_renames->nr; i++) {
1185 sre = b_renames->items[i].util;
1186 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1187 = sre->dst_entry;
1188 }
1189
1190 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1191 int compare;
1192 char *src;
1193 struct path_list *renames1, *renames2, *renames2Dst;
1194 struct rename *ren1 = NULL, *ren2 = NULL;
1195 const char *branch1, *branch2;
1196 const char *ren1_src, *ren1_dst;
1197
1198 if (i >= a_renames->nr) {
1199 compare = 1;
1200 ren2 = b_renames->items[j++].util;
1201 } else if (j >= b_renames->nr) {
1202 compare = -1;
1203 ren1 = a_renames->items[i++].util;
1204 } else {
1205 compare = strcmp(a_renames->items[i].path,
1206 b_renames->items[j].path);
1207 if (compare <= 0)
1208 ren1 = a_renames->items[i++].util;
1209 if (compare >= 0)
1210 ren2 = b_renames->items[j++].util;
1211 }
1212
1213 /* TODO: refactor, so that 1/2 are not needed */
1214 if (ren1) {
1215 renames1 = a_renames;
1216 renames2 = b_renames;
1217 renames2Dst = &b_by_dst;
1218 branch1 = a_branch;
1219 branch2 = b_branch;
1220 } else {
1221 struct rename *tmp;
1222 renames1 = b_renames;
1223 renames2 = a_renames;
1224 renames2Dst = &a_by_dst;
1225 branch1 = b_branch;
1226 branch2 = a_branch;
1227 tmp = ren2;
1228 ren2 = ren1;
1229 ren1 = tmp;
1230 }
1231 src = ren1->pair->one->path;
1232
1233 ren1->dst_entry->processed = 1;
1234 ren1->src_entry->processed = 1;
1235
1236 if (ren1->processed)
1237 continue;
1238 ren1->processed = 1;
1239
1240 ren1_src = ren1->pair->one->path;
1241 ren1_dst = ren1->pair->two->path;
1242
1243 if (ren2) {
1244 const char *ren2_src = ren2->pair->one->path;
1245 const char *ren2_dst = ren2->pair->two->path;
1246 /* Renamed in 1 and renamed in 2 */
1247 if (strcmp(ren1_src, ren2_src) != 0)
1248 die("ren1.src != ren2.src");
1249 ren2->dst_entry->processed = 1;
1250 ren2->processed = 1;
1251 if (strcmp(ren1_dst, ren2_dst) != 0) {
1252 clean_merge = 0;
1253 output(1, "CONFLICT (rename/rename): "
1254 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1255 "rename \"%s\"->\"%s\" in \"%s\"%s",
1256 src, ren1_dst, branch1,
1257 src, ren2_dst, branch2,
1258 index_only ? " (left unresolved)": "");
1259 if (index_only) {
1260 remove_file_from_cache(src);
1261 update_file(0, ren1->pair->one->sha1,
1262 ren1->pair->one->mode, src);
1263 }
1264 conflict_rename_rename(ren1, branch1, ren2, branch2);
1265 } else {
1266 struct merge_file_info mfi;
1267 remove_file(1, ren1_src, 1);
1268 mfi = merge_file(ren1->pair->one,
1269 ren1->pair->two,
1270 ren2->pair->two,
1271 branch1,
1272 branch2);
1273 if (mfi.merge || !mfi.clean)
1274 output(1, "Renamed %s->%s", src, ren1_dst);
1275
1276 if (mfi.merge)
1277 output(2, "Auto-merged %s", ren1_dst);
1278
1279 if (!mfi.clean) {
1280 output(1, "CONFLICT (content): merge conflict in %s",
1281 ren1_dst);
1282 clean_merge = 0;
1283
1284 if (!index_only)
1285 update_stages(ren1_dst,
1286 ren1->pair->one,
1287 ren1->pair->two,
1288 ren2->pair->two,
1289 1 /* clear */);
1290 }
1291 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1292 }
1293 } else {
1294 /* Renamed in 1, maybe changed in 2 */
1295 struct path_list_item *item;
1296 /* we only use sha1 and mode of these */
1297 struct diff_filespec src_other, dst_other;
1298 int try_merge, stage = a_renames == renames1 ? 3: 2;
1299
1300 remove_file(1, ren1_src, index_only || stage == 3);
1301
1302 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1303 src_other.mode = ren1->src_entry->stages[stage].mode;
1304 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1305 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1306
1307 try_merge = 0;
1308
1309 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1310 clean_merge = 0;
1311 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1312 " directory %s added in %s",
1313 ren1_src, ren1_dst, branch1,
1314 ren1_dst, branch2);
1315 conflict_rename_dir(ren1, branch1);
1316 } else if (sha_eq(src_other.sha1, null_sha1)) {
1317 clean_merge = 0;
1318 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1319 "and deleted in %s",
1320 ren1_src, ren1_dst, branch1,
1321 branch2);
1322 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1323 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1324 const char *new_path;
1325 clean_merge = 0;
1326 try_merge = 1;
1327 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1328 "%s added in %s",
1329 ren1_src, ren1_dst, branch1,
1330 ren1_dst, branch2);
1331 new_path = unique_path(ren1_dst, branch2);
1332 output(1, "Added as %s instead", new_path);
1333 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1334 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1335 ren2 = item->util;
1336 clean_merge = 0;
1337 ren2->processed = 1;
1338 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1339 "Renamed %s->%s in %s",
1340 ren1_src, ren1_dst, branch1,
1341 ren2->pair->one->path, ren2->pair->two->path, branch2);
1342 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1343 } else
1344 try_merge = 1;
1345
1346 if (try_merge) {
1347 struct diff_filespec *o, *a, *b;
1348 struct merge_file_info mfi;
1349 src_other.path = (char *)ren1_src;
1350
1351 o = ren1->pair->one;
1352 if (a_renames == renames1) {
1353 a = ren1->pair->two;
1354 b = &src_other;
1355 } else {
1356 b = ren1->pair->two;
1357 a = &src_other;
1358 }
1359 mfi = merge_file(o, a, b,
1360 a_branch, b_branch);
1361
1362 if (mfi.clean &&
1363 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1364 mfi.mode == ren1->pair->two->mode)
1365 /*
1366 * This messaged is part of
1367 * t6022 test. If you change
1368 * it update the test too.
1369 */
1370 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1371 else {
1372 if (mfi.merge || !mfi.clean)
1373 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1374 if (mfi.merge)
1375 output(2, "Auto-merged %s", ren1_dst);
1376 if (!mfi.clean) {
1377 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1378 ren1_dst);
1379 clean_merge = 0;
1380
1381 if (!index_only)
1382 update_stages(ren1_dst,
1383 o, a, b, 1);
1384 }
1385 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1386 }
1387 }
1388 }
1389 }
1390 path_list_clear(&a_by_dst, 0);
1391 path_list_clear(&b_by_dst, 0);
1392
1393 return clean_merge;
1394 }
1395
1396 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1397 {
1398 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1399 }
1400
1401 /* Per entry merge function */
1402 static int process_entry(const char *path, struct stage_data *entry,
1403 const char *branch1,
1404 const char *branch2)
1405 {
1406 /*
1407 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1408 print_index_entry("\tpath: ", entry);
1409 */
1410 int clean_merge = 1;
1411 unsigned o_mode = entry->stages[1].mode;
1412 unsigned a_mode = entry->stages[2].mode;
1413 unsigned b_mode = entry->stages[3].mode;
1414 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1415 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1416 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1417
1418 if (o_sha && (!a_sha || !b_sha)) {
1419 /* Case A: Deleted in one */
1420 if ((!a_sha && !b_sha) ||
1421 (sha_eq(a_sha, o_sha) && !b_sha) ||
1422 (!a_sha && sha_eq(b_sha, o_sha))) {
1423 /* Deleted in both or deleted in one and
1424 * unchanged in the other */
1425 if (a_sha)
1426 output(2, "Removed %s", path);
1427 /* do not touch working file if it did not exist */
1428 remove_file(1, path, !a_sha);
1429 } else {
1430 /* Deleted in one and changed in the other */
1431 clean_merge = 0;
1432 if (!a_sha) {
1433 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1434 "and modified in %s. Version %s of %s left in tree.",
1435 path, branch1,
1436 branch2, branch2, path);
1437 update_file(0, b_sha, b_mode, path);
1438 } else {
1439 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1440 "and modified in %s. Version %s of %s left in tree.",
1441 path, branch2,
1442 branch1, branch1, path);
1443 update_file(0, a_sha, a_mode, path);
1444 }
1445 }
1446
1447 } else if ((!o_sha && a_sha && !b_sha) ||
1448 (!o_sha && !a_sha && b_sha)) {
1449 /* Case B: Added in one. */
1450 const char *add_branch;
1451 const char *other_branch;
1452 unsigned mode;
1453 const unsigned char *sha;
1454 const char *conf;
1455
1456 if (a_sha) {
1457 add_branch = branch1;
1458 other_branch = branch2;
1459 mode = a_mode;
1460 sha = a_sha;
1461 conf = "file/directory";
1462 } else {
1463 add_branch = branch2;
1464 other_branch = branch1;
1465 mode = b_mode;
1466 sha = b_sha;
1467 conf = "directory/file";
1468 }
1469 if (path_list_has_path(&current_directory_set, path)) {
1470 const char *new_path = unique_path(path, add_branch);
1471 clean_merge = 0;
1472 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1473 "Added %s as %s",
1474 conf, path, other_branch, path, new_path);
1475 remove_file(0, path, 0);
1476 update_file(0, sha, mode, new_path);
1477 } else {
1478 output(2, "Added %s", path);
1479 update_file(1, sha, mode, path);
1480 }
1481 } else if (a_sha && b_sha) {
1482 /* Case C: Added in both (check for same permissions) and */
1483 /* case D: Modified in both, but differently. */
1484 const char *reason = "content";
1485 struct merge_file_info mfi;
1486 struct diff_filespec o, a, b;
1487
1488 if (!o_sha) {
1489 reason = "add/add";
1490 o_sha = (unsigned char *)null_sha1;
1491 }
1492 output(2, "Auto-merged %s", path);
1493 o.path = a.path = b.path = (char *)path;
1494 hashcpy(o.sha1, o_sha);
1495 o.mode = o_mode;
1496 hashcpy(a.sha1, a_sha);
1497 a.mode = a_mode;
1498 hashcpy(b.sha1, b_sha);
1499 b.mode = b_mode;
1500
1501 mfi = merge_file(&o, &a, &b,
1502 branch1, branch2);
1503
1504 if (mfi.clean)
1505 update_file(1, mfi.sha, mfi.mode, path);
1506 else {
1507 clean_merge = 0;
1508 output(1, "CONFLICT (%s): Merge conflict in %s",
1509 reason, path);
1510
1511 if (index_only)
1512 update_file(0, mfi.sha, mfi.mode, path);
1513 else
1514 update_file_flags(mfi.sha, mfi.mode, path,
1515 0 /* update_cache */, 1 /* update_working_directory */);
1516 }
1517 } else if (!o_sha && !a_sha && !b_sha) {
1518 /*
1519 * this entry was deleted altogether. a_mode == 0 means
1520 * we had that path and want to actively remove it.
1521 */
1522 remove_file(1, path, !a_mode);
1523 } else
1524 die("Fatal merge failure, shouldn't happen.");
1525
1526 return clean_merge;
1527 }
1528
1529 static int merge_trees(struct tree *head,
1530 struct tree *merge,
1531 struct tree *common,
1532 const char *branch1,
1533 const char *branch2,
1534 struct tree **result)
1535 {
1536 int code, clean;
1537
1538 if (subtree_merge) {
1539 merge = shift_tree_object(head, merge);
1540 common = shift_tree_object(head, common);
1541 }
1542
1543 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1544 output(0, "Already uptodate!");
1545 *result = head;
1546 return 1;
1547 }
1548
1549 code = git_merge_trees(index_only, common, head, merge);
1550
1551 if (code != 0)
1552 die("merging of trees %s and %s failed",
1553 sha1_to_hex(head->object.sha1),
1554 sha1_to_hex(merge->object.sha1));
1555
1556 if (unmerged_index()) {
1557 struct path_list *entries, *re_head, *re_merge;
1558 int i;
1559 path_list_clear(&current_file_set, 1);
1560 path_list_clear(&current_directory_set, 1);
1561 get_files_dirs(head);
1562 get_files_dirs(merge);
1563
1564 entries = get_unmerged();
1565 re_head = get_renames(head, common, head, merge, entries);
1566 re_merge = get_renames(merge, common, head, merge, entries);
1567 clean = process_renames(re_head, re_merge,
1568 branch1, branch2);
1569 for (i = 0; i < entries->nr; i++) {
1570 const char *path = entries->items[i].path;
1571 struct stage_data *e = entries->items[i].util;
1572 if (!e->processed
1573 && !process_entry(path, e, branch1, branch2))
1574 clean = 0;
1575 }
1576
1577 path_list_clear(re_merge, 0);
1578 path_list_clear(re_head, 0);
1579 path_list_clear(entries, 1);
1580
1581 }
1582 else
1583 clean = 1;
1584
1585 if (index_only)
1586 *result = git_write_tree();
1587
1588 return clean;
1589 }
1590
1591 static struct commit_list *reverse_commit_list(struct commit_list *list)
1592 {
1593 struct commit_list *next = NULL, *current, *backup;
1594 for (current = list; current; current = backup) {
1595 backup = current->next;
1596 current->next = next;
1597 next = current;
1598 }
1599 return next;
1600 }
1601
1602 /*
1603 * Merge the commits h1 and h2, return the resulting virtual
1604 * commit object and a flag indicating the cleanness of the merge.
1605 */
1606 static int merge(struct commit *h1,
1607 struct commit *h2,
1608 const char *branch1,
1609 const char *branch2,
1610 struct commit_list *ca,
1611 struct commit **result)
1612 {
1613 struct commit_list *iter;
1614 struct commit *merged_common_ancestors;
1615 struct tree *mrtree;
1616 int clean;
1617
1618 if (show(4)) {
1619 output(4, "Merging:");
1620 output_commit_title(h1);
1621 output_commit_title(h2);
1622 }
1623
1624 if (!ca) {
1625 ca = get_merge_bases(h1, h2, 1);
1626 ca = reverse_commit_list(ca);
1627 }
1628
1629 if (show(5)) {
1630 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1631 for (iter = ca; iter; iter = iter->next)
1632 output_commit_title(iter->item);
1633 }
1634
1635 merged_common_ancestors = pop_commit(&ca);
1636 if (merged_common_ancestors == NULL) {
1637 /* if there is no common ancestor, make an empty tree */
1638 struct tree *tree = xcalloc(1, sizeof(struct tree));
1639
1640 tree->object.parsed = 1;
1641 tree->object.type = OBJ_TREE;
1642 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1643 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1644 }
1645
1646 for (iter = ca; iter; iter = iter->next) {
1647 call_depth++;
1648 /*
1649 * When the merge fails, the result contains files
1650 * with conflict markers. The cleanness flag is
1651 * ignored, it was never actually used, as result of
1652 * merge_trees has always overwritten it: the committed
1653 * "conflicts" were already resolved.
1654 */
1655 discard_cache();
1656 merge(merged_common_ancestors, iter->item,
1657 "Temporary merge branch 1",
1658 "Temporary merge branch 2",
1659 NULL,
1660 &merged_common_ancestors);
1661 call_depth--;
1662
1663 if (!merged_common_ancestors)
1664 die("merge returned no commit");
1665 }
1666
1667 discard_cache();
1668 if (!call_depth) {
1669 read_cache();
1670 index_only = 0;
1671 } else
1672 index_only = 1;
1673
1674 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1675 branch1, branch2, &mrtree);
1676
1677 if (index_only) {
1678 *result = make_virtual_commit(mrtree, "merged tree");
1679 commit_list_insert(h1, &(*result)->parents);
1680 commit_list_insert(h2, &(*result)->parents->next);
1681 }
1682 flush_output();
1683 return clean;
1684 }
1685
1686 static const char *better_branch_name(const char *branch)
1687 {
1688 static char githead_env[8 + 40 + 1];
1689 char *name;
1690
1691 if (strlen(branch) != 40)
1692 return branch;
1693 sprintf(githead_env, "GITHEAD_%s", branch);
1694 name = getenv(githead_env);
1695 return name ? name : branch;
1696 }
1697
1698 static struct commit *get_ref(const char *ref)
1699 {
1700 unsigned char sha1[20];
1701 struct object *object;
1702
1703 if (get_sha1(ref, sha1))
1704 die("Could not resolve ref '%s'", ref);
1705 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1706 if (object->type == OBJ_TREE)
1707 return make_virtual_commit((struct tree*)object,
1708 better_branch_name(ref));
1709 if (object->type != OBJ_COMMIT)
1710 return NULL;
1711 if (parse_commit((struct commit *)object))
1712 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1713 return (struct commit *)object;
1714 }
1715
1716 static int merge_config(const char *var, const char *value)
1717 {
1718 if (!strcasecmp(var, "merge.verbosity")) {
1719 verbosity = git_config_int(var, value);
1720 return 0;
1721 }
1722 return git_default_config(var, value);
1723 }
1724
1725 int main(int argc, char *argv[])
1726 {
1727 static const char *bases[20];
1728 static unsigned bases_count = 0;
1729 int i, clean;
1730 const char *branch1, *branch2;
1731 struct commit *result, *h1, *h2;
1732 struct commit_list *ca = NULL;
1733 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1734 int index_fd;
1735
1736 if (argv[0]) {
1737 int namelen = strlen(argv[0]);
1738 if (8 < namelen &&
1739 !strcmp(argv[0] + namelen - 8, "-subtree"))
1740 subtree_merge = 1;
1741 }
1742
1743 git_config(merge_config);
1744 if (getenv("GIT_MERGE_VERBOSITY"))
1745 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1746
1747 if (argc < 4)
1748 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1749
1750 for (i = 1; i < argc; ++i) {
1751 if (!strcmp(argv[i], "--"))
1752 break;
1753 if (bases_count < sizeof(bases)/sizeof(*bases))
1754 bases[bases_count++] = argv[i];
1755 }
1756 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1757 die("Not handling anything other than two heads merge.");
1758 if (verbosity >= 5)
1759 buffer_output = 0;
1760
1761 branch1 = argv[++i];
1762 branch2 = argv[++i];
1763
1764 h1 = get_ref(branch1);
1765 h2 = get_ref(branch2);
1766
1767 branch1 = better_branch_name(branch1);
1768 branch2 = better_branch_name(branch2);
1769
1770 if (show(3))
1771 printf("Merging %s with %s\n", branch1, branch2);
1772
1773 index_fd = hold_locked_index(lock, 1);
1774
1775 for (i = 0; i < bases_count; i++) {
1776 struct commit *ancestor = get_ref(bases[i]);
1777 ca = commit_list_insert(ancestor, &ca);
1778 }
1779 clean = merge(h1, h2, branch1, branch2, ca, &result);
1780
1781 if (active_cache_changed &&
1782 (write_cache(index_fd, active_cache, active_nr) ||
1783 close(index_fd) || commit_locked_index(lock)))
1784 die ("unable to write %s", get_index_file());
1785
1786 return clean ? 0: 1;
1787 }
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