403a4c8bca3062c8fa586e369b3fd1308c919641
[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 #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()
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 int git_merge_trees(int index_only,
220 struct tree *common,
221 struct tree *head,
222 struct tree *merge)
223 {
224 int rc;
225 struct object_list *trees = NULL;
226 struct unpack_trees_options opts;
227
228 memset(&opts, 0, sizeof(opts));
229 if (index_only)
230 opts.index_only = 1;
231 else
232 opts.update = 1;
233 opts.merge = 1;
234 opts.head_idx = 2;
235 opts.fn = threeway_merge;
236
237 object_list_append(&common->object, &trees);
238 object_list_append(&head->object, &trees);
239 object_list_append(&merge->object, &trees);
240
241 rc = unpack_trees(trees, &opts);
242 cache_tree_free(&active_cache_tree);
243 return rc;
244 }
245
246 static int unmerged_index(void)
247 {
248 int i;
249 for (i = 0; i < active_nr; i++) {
250 struct cache_entry *ce = active_cache[i];
251 if (ce_stage(ce))
252 return 1;
253 }
254 return 0;
255 }
256
257 static struct tree *git_write_tree(void)
258 {
259 struct tree *result = NULL;
260
261 if (unmerged_index()) {
262 int i;
263 output(0, "There are unmerged index entries:");
264 for (i = 0; i < active_nr; i++) {
265 struct cache_entry *ce = active_cache[i];
266 if (ce_stage(ce))
267 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
268 }
269 return NULL;
270 }
271
272 if (!active_cache_tree)
273 active_cache_tree = cache_tree();
274
275 if (!cache_tree_fully_valid(active_cache_tree) &&
276 cache_tree_update(active_cache_tree,
277 active_cache, active_nr, 0, 0) < 0)
278 die("error building trees");
279
280 result = lookup_tree(active_cache_tree->sha1);
281
282 return result;
283 }
284
285 static int save_files_dirs(const unsigned char *sha1,
286 const char *base, int baselen, const char *path,
287 unsigned int mode, int stage)
288 {
289 int len = strlen(path);
290 char *newpath = xmalloc(baselen + len + 1);
291 memcpy(newpath, base, baselen);
292 memcpy(newpath + baselen, path, len);
293 newpath[baselen + len] = '\0';
294
295 if (S_ISDIR(mode))
296 path_list_insert(newpath, &current_directory_set);
297 else
298 path_list_insert(newpath, &current_file_set);
299 free(newpath);
300
301 return READ_TREE_RECURSIVE;
302 }
303
304 static int get_files_dirs(struct tree *tree)
305 {
306 int n;
307 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
308 return 0;
309 n = current_file_set.nr + current_directory_set.nr;
310 return n;
311 }
312
313 /*
314 * Returns a index_entry instance which doesn't have to correspond to
315 * a real cache entry in Git's index.
316 */
317 static struct stage_data *insert_stage_data(const char *path,
318 struct tree *o, struct tree *a, struct tree *b,
319 struct path_list *entries)
320 {
321 struct path_list_item *item;
322 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
323 get_tree_entry(o->object.sha1, path,
324 e->stages[1].sha, &e->stages[1].mode);
325 get_tree_entry(a->object.sha1, path,
326 e->stages[2].sha, &e->stages[2].mode);
327 get_tree_entry(b->object.sha1, path,
328 e->stages[3].sha, &e->stages[3].mode);
329 item = path_list_insert(path, entries);
330 item->util = e;
331 return e;
332 }
333
334 /*
335 * Create a dictionary mapping file names to stage_data objects. The
336 * dictionary contains one entry for every path with a non-zero stage entry.
337 */
338 static struct path_list *get_unmerged(void)
339 {
340 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
341 int i;
342
343 unmerged->strdup_paths = 1;
344
345 for (i = 0; i < active_nr; i++) {
346 struct path_list_item *item;
347 struct stage_data *e;
348 struct cache_entry *ce = active_cache[i];
349 if (!ce_stage(ce))
350 continue;
351
352 item = path_list_lookup(ce->name, unmerged);
353 if (!item) {
354 item = path_list_insert(ce->name, unmerged);
355 item->util = xcalloc(1, sizeof(struct stage_data));
356 }
357 e = item->util;
358 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
359 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
360 }
361
362 return unmerged;
363 }
364
365 struct rename
366 {
367 struct diff_filepair *pair;
368 struct stage_data *src_entry;
369 struct stage_data *dst_entry;
370 unsigned processed:1;
371 };
372
373 /*
374 * Get information of all renames which occurred between 'o_tree' and
375 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
376 * 'b_tree') to be able to associate the correct cache entries with
377 * the rename information. 'tree' is always equal to either a_tree or b_tree.
378 */
379 static struct path_list *get_renames(struct tree *tree,
380 struct tree *o_tree,
381 struct tree *a_tree,
382 struct tree *b_tree,
383 struct path_list *entries)
384 {
385 int i;
386 struct path_list *renames;
387 struct diff_options opts;
388
389 renames = xcalloc(1, sizeof(struct path_list));
390 diff_setup(&opts);
391 opts.recursive = 1;
392 opts.detect_rename = DIFF_DETECT_RENAME;
393 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
394 if (diff_setup_done(&opts) < 0)
395 die("diff setup failed");
396 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
397 diffcore_std(&opts);
398 for (i = 0; i < diff_queued_diff.nr; ++i) {
399 struct path_list_item *item;
400 struct rename *re;
401 struct diff_filepair *pair = diff_queued_diff.queue[i];
402 if (pair->status != 'R') {
403 diff_free_filepair(pair);
404 continue;
405 }
406 re = xmalloc(sizeof(*re));
407 re->processed = 0;
408 re->pair = pair;
409 item = path_list_lookup(re->pair->one->path, entries);
410 if (!item)
411 re->src_entry = insert_stage_data(re->pair->one->path,
412 o_tree, a_tree, b_tree, entries);
413 else
414 re->src_entry = item->util;
415
416 item = path_list_lookup(re->pair->two->path, entries);
417 if (!item)
418 re->dst_entry = insert_stage_data(re->pair->two->path,
419 o_tree, a_tree, b_tree, entries);
420 else
421 re->dst_entry = item->util;
422 item = path_list_insert(pair->one->path, renames);
423 item->util = re;
424 }
425 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
426 diff_queued_diff.nr = 0;
427 diff_flush(&opts);
428 return renames;
429 }
430
431 static int update_stages(const char *path, struct diff_filespec *o,
432 struct diff_filespec *a, struct diff_filespec *b,
433 int clear)
434 {
435 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
436 if (clear)
437 if (remove_file_from_cache(path))
438 return -1;
439 if (o)
440 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
441 return -1;
442 if (a)
443 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
444 return -1;
445 if (b)
446 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
447 return -1;
448 return 0;
449 }
450
451 static int remove_path(const char *name)
452 {
453 int ret, len;
454 char *slash, *dirs;
455
456 ret = unlink(name);
457 if (ret)
458 return ret;
459 len = strlen(name);
460 dirs = xmalloc(len+1);
461 memcpy(dirs, name, len);
462 dirs[len] = '\0';
463 while ((slash = strrchr(name, '/'))) {
464 *slash = '\0';
465 len = slash - name;
466 if (rmdir(name) != 0)
467 break;
468 }
469 free(dirs);
470 return ret;
471 }
472
473 static int remove_file(int clean, const char *path, int no_wd)
474 {
475 int update_cache = index_only || clean;
476 int update_working_directory = !index_only && !no_wd;
477
478 if (update_cache) {
479 if (remove_file_from_cache(path))
480 return -1;
481 }
482 if (update_working_directory) {
483 unlink(path);
484 if (errno != ENOENT || errno != EISDIR)
485 return -1;
486 remove_path(path);
487 }
488 return 0;
489 }
490
491 static char *unique_path(const char *path, const char *branch)
492 {
493 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
494 int suffix = 0;
495 struct stat st;
496 char *p = newpath + strlen(path);
497 strcpy(newpath, path);
498 *(p++) = '~';
499 strcpy(p, branch);
500 for (; *p; ++p)
501 if ('/' == *p)
502 *p = '_';
503 while (path_list_has_path(&current_file_set, newpath) ||
504 path_list_has_path(&current_directory_set, newpath) ||
505 lstat(newpath, &st) == 0)
506 sprintf(p, "_%d", suffix++);
507
508 path_list_insert(newpath, &current_file_set);
509 return newpath;
510 }
511
512 static int mkdir_p(const char *path, unsigned long mode)
513 {
514 /* path points to cache entries, so xstrdup before messing with it */
515 char *buf = xstrdup(path);
516 int result = safe_create_leading_directories(buf);
517 free(buf);
518 return result;
519 }
520
521 static void flush_buffer(int fd, const char *buf, unsigned long size)
522 {
523 while (size > 0) {
524 long ret = write_in_full(fd, buf, size);
525 if (ret < 0) {
526 /* Ignore epipe */
527 if (errno == EPIPE)
528 break;
529 die("merge-recursive: %s", strerror(errno));
530 } else if (!ret) {
531 die("merge-recursive: disk full?");
532 }
533 size -= ret;
534 buf += ret;
535 }
536 }
537
538 static int make_room_for_path(const char *path)
539 {
540 int status;
541 const char *msg = "failed to create path '%s'%s";
542
543 status = mkdir_p(path, 0777);
544 if (status) {
545 if (status == -3) {
546 /* something else exists */
547 error(msg, path, ": perhaps a D/F conflict?");
548 return -1;
549 }
550 die(msg, path, "");
551 }
552
553 /* Successful unlink is good.. */
554 if (!unlink(path))
555 return 0;
556 /* .. and so is no existing file */
557 if (errno == ENOENT)
558 return 0;
559 /* .. but not some other error (who really cares what?) */
560 return error(msg, path, ": perhaps a D/F conflict?");
561 }
562
563 static void update_file_flags(const unsigned char *sha,
564 unsigned mode,
565 const char *path,
566 int update_cache,
567 int update_wd)
568 {
569 if (index_only)
570 update_wd = 0;
571
572 if (update_wd) {
573 enum object_type type;
574 void *buf;
575 unsigned long size;
576
577 buf = read_sha1_file(sha, &type, &size);
578 if (!buf)
579 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
580 if (type != OBJ_BLOB)
581 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
582
583 if (make_room_for_path(path) < 0) {
584 update_wd = 0;
585 goto update_index;
586 }
587 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
588 int fd;
589 if (mode & 0100)
590 mode = 0777;
591 else
592 mode = 0666;
593 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
594 if (fd < 0)
595 die("failed to open %s: %s", path, strerror(errno));
596 flush_buffer(fd, buf, size);
597 close(fd);
598 } else if (S_ISLNK(mode)) {
599 char *lnk = xmalloc(size + 1);
600 memcpy(lnk, buf, size);
601 lnk[size] = '\0';
602 mkdir_p(path, 0777);
603 unlink(path);
604 symlink(lnk, path);
605 free(lnk);
606 } else
607 die("do not know what to do with %06o %s '%s'",
608 mode, sha1_to_hex(sha), path);
609 }
610 update_index:
611 if (update_cache)
612 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
613 }
614
615 static void update_file(int clean,
616 const unsigned char *sha,
617 unsigned mode,
618 const char *path)
619 {
620 update_file_flags(sha, mode, path, index_only || clean, !index_only);
621 }
622
623 /* Low level file merging, update and removal */
624
625 struct merge_file_info
626 {
627 unsigned char sha[20];
628 unsigned mode;
629 unsigned clean:1,
630 merge:1;
631 };
632
633 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
634 {
635 unsigned long size;
636 enum object_type type;
637
638 if (!hashcmp(sha1, null_sha1)) {
639 mm->ptr = xstrdup("");
640 mm->size = 0;
641 return;
642 }
643
644 mm->ptr = read_sha1_file(sha1, &type, &size);
645 if (!mm->ptr || type != OBJ_BLOB)
646 die("unable to read blob object %s", sha1_to_hex(sha1));
647 mm->size = size;
648 }
649
650 /*
651 * Customizable low-level merge drivers support.
652 */
653
654 struct ll_merge_driver;
655 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
656 const char *path,
657 mmfile_t *orig,
658 mmfile_t *src1, const char *name1,
659 mmfile_t *src2, const char *name2,
660 mmbuffer_t *result);
661
662 struct ll_merge_driver {
663 const char *name;
664 const char *description;
665 ll_merge_fn fn;
666 const char *recursive;
667 struct ll_merge_driver *next;
668 char *cmdline;
669 };
670
671 /*
672 * Built-in low-levels
673 */
674 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
675 const char *path_unused,
676 mmfile_t *orig,
677 mmfile_t *src1, const char *name1,
678 mmfile_t *src2, const char *name2,
679 mmbuffer_t *result)
680 {
681 xpparam_t xpp;
682
683 memset(&xpp, 0, sizeof(xpp));
684 return xdl_merge(orig,
685 src1, name1,
686 src2, name2,
687 &xpp, XDL_MERGE_ZEALOUS,
688 result);
689 }
690
691 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
692 const char *path_unused,
693 mmfile_t *orig,
694 mmfile_t *src1, const char *name1,
695 mmfile_t *src2, const char *name2,
696 mmbuffer_t *result)
697 {
698 char *src, *dst;
699 long size;
700 const int marker_size = 7;
701
702 int status = ll_xdl_merge(drv_unused, path_unused,
703 orig, src1, NULL, src2, NULL, result);
704 if (status <= 0)
705 return status;
706 size = result->size;
707 src = dst = result->ptr;
708 while (size) {
709 char ch;
710 if ((marker_size < size) &&
711 (*src == '<' || *src == '=' || *src == '>')) {
712 int i;
713 ch = *src;
714 for (i = 0; i < marker_size; i++)
715 if (src[i] != ch)
716 goto not_a_marker;
717 if (src[marker_size] != '\n')
718 goto not_a_marker;
719 src += marker_size + 1;
720 size -= marker_size + 1;
721 continue;
722 }
723 not_a_marker:
724 do {
725 ch = *src++;
726 *dst++ = ch;
727 size--;
728 } while (ch != '\n' && size);
729 }
730 result->size = dst - result->ptr;
731 return 0;
732 }
733
734 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
735 const char *path_unused,
736 mmfile_t *orig,
737 mmfile_t *src1, const char *name1,
738 mmfile_t *src2, const char *name2,
739 mmbuffer_t *result)
740 {
741 /*
742 * The tentative merge result is "ours" for the final round,
743 * or common ancestor for an internal merge. Still return
744 * "conflicted merge" status.
745 */
746 mmfile_t *stolen = index_only ? orig : src1;
747
748 result->ptr = stolen->ptr;
749 result->size = stolen->size;
750 stolen->ptr = NULL;
751 return 1;
752 }
753
754 #define LL_BINARY_MERGE 0
755 #define LL_TEXT_MERGE 1
756 #define LL_UNION_MERGE 2
757 static struct ll_merge_driver ll_merge_drv[] = {
758 { "binary", "built-in binary merge", ll_binary_merge },
759 { "text", "built-in 3-way text merge", ll_xdl_merge },
760 { "union", "built-in union merge", ll_union_merge },
761 };
762
763 static void create_temp(mmfile_t *src, char *path)
764 {
765 int fd;
766
767 strcpy(path, ".merge_file_XXXXXX");
768 fd = mkstemp(path);
769 if (fd < 0)
770 die("unable to create temp-file");
771 if (write_in_full(fd, src->ptr, src->size) != src->size)
772 die("unable to write temp-file");
773 close(fd);
774 }
775
776 /*
777 * User defined low-level merge driver support.
778 */
779 static int ll_ext_merge(const struct ll_merge_driver *fn,
780 const char *path,
781 mmfile_t *orig,
782 mmfile_t *src1, const char *name1,
783 mmfile_t *src2, const char *name2,
784 mmbuffer_t *result)
785 {
786 char temp[3][50];
787 char cmdbuf[2048];
788 struct interp table[] = {
789 { "%O" },
790 { "%A" },
791 { "%B" },
792 };
793 struct child_process child;
794 const char *args[20];
795 int status, fd, i;
796 struct stat st;
797
798 if (fn->cmdline == NULL)
799 die("custom merge driver %s lacks command line.", fn->name);
800
801 result->ptr = NULL;
802 result->size = 0;
803 create_temp(orig, temp[0]);
804 create_temp(src1, temp[1]);
805 create_temp(src2, temp[2]);
806
807 interp_set_entry(table, 0, temp[0]);
808 interp_set_entry(table, 1, temp[1]);
809 interp_set_entry(table, 2, temp[2]);
810
811 output(1, "merging %s using %s", path,
812 fn->description ? fn->description : fn->name);
813
814 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
815
816 memset(&child, 0, sizeof(child));
817 child.argv = args;
818 args[0] = "sh";
819 args[1] = "-c";
820 args[2] = cmdbuf;
821 args[3] = NULL;
822
823 status = run_command(&child);
824 if (status < -ERR_RUN_COMMAND_FORK)
825 ; /* failure in run-command */
826 else
827 status = -status;
828 fd = open(temp[1], O_RDONLY);
829 if (fd < 0)
830 goto bad;
831 if (fstat(fd, &st))
832 goto close_bad;
833 result->size = st.st_size;
834 result->ptr = xmalloc(result->size + 1);
835 if (read_in_full(fd, result->ptr, result->size) != result->size) {
836 free(result->ptr);
837 result->ptr = NULL;
838 result->size = 0;
839 }
840 close_bad:
841 close(fd);
842 bad:
843 for (i = 0; i < 3; i++)
844 unlink(temp[i]);
845 return status;
846 }
847
848 /*
849 * merge.default and merge.driver configuration items
850 */
851 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
852 static const char *default_ll_merge;
853
854 static int read_merge_config(const char *var, const char *value)
855 {
856 struct ll_merge_driver *fn;
857 const char *ep, *name;
858 int namelen;
859
860 if (!strcmp(var, "merge.default")) {
861 if (value)
862 default_ll_merge = strdup(value);
863 return 0;
864 }
865
866 /*
867 * We are not interested in anything but "merge.<name>.variable";
868 * especially, we do not want to look at variables such as
869 * "merge.summary", "merge.tool", and "merge.verbosity".
870 */
871 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
872 return 0;
873
874 /*
875 * Find existing one as we might be processing merge.<name>.var2
876 * after seeing merge.<name>.var1.
877 */
878 name = var + 6;
879 namelen = ep - name;
880 for (fn = ll_user_merge; fn; fn = fn->next)
881 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
882 break;
883 if (!fn) {
884 char *namebuf;
885 fn = xcalloc(1, sizeof(struct ll_merge_driver));
886 namebuf = xmalloc(namelen + 1);
887 memcpy(namebuf, name, namelen);
888 namebuf[namelen] = 0;
889 fn->name = namebuf;
890 fn->fn = ll_ext_merge;
891 fn->next = NULL;
892 *ll_user_merge_tail = fn;
893 ll_user_merge_tail = &(fn->next);
894 }
895
896 ep++;
897
898 if (!strcmp("name", ep)) {
899 if (!value)
900 return error("%s: lacks value", var);
901 fn->description = strdup(value);
902 return 0;
903 }
904
905 if (!strcmp("driver", ep)) {
906 if (!value)
907 return error("%s: lacks value", var);
908 /*
909 * merge.<name>.driver specifies the command line:
910 *
911 * command-line
912 *
913 * The command-line will be interpolated with the following
914 * tokens and is given to the shell:
915 *
916 * %O - temporary file name for the merge base.
917 * %A - temporary file name for our version.
918 * %B - temporary file name for the other branches' version.
919 *
920 * The external merge driver should write the results in the
921 * file named by %A, and signal that it has done with zero exit
922 * status.
923 */
924 fn->cmdline = strdup(value);
925 return 0;
926 }
927
928 if (!strcmp("recursive", ep)) {
929 if (!value)
930 return error("%s: lacks value", var);
931 fn->recursive = strdup(value);
932 return 0;
933 }
934
935 return 0;
936 }
937
938 static void initialize_ll_merge(void)
939 {
940 if (ll_user_merge_tail)
941 return;
942 ll_user_merge_tail = &ll_user_merge;
943 git_config(read_merge_config);
944 }
945
946 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
947 {
948 struct ll_merge_driver *fn;
949 const char *name;
950 int i;
951
952 initialize_ll_merge();
953
954 if (ATTR_TRUE(merge_attr))
955 return &ll_merge_drv[LL_TEXT_MERGE];
956 else if (ATTR_FALSE(merge_attr))
957 return &ll_merge_drv[LL_BINARY_MERGE];
958 else if (ATTR_UNSET(merge_attr)) {
959 if (!default_ll_merge)
960 return &ll_merge_drv[LL_TEXT_MERGE];
961 else
962 name = default_ll_merge;
963 }
964 else
965 name = merge_attr;
966
967 for (fn = ll_user_merge; fn; fn = fn->next)
968 if (!strcmp(fn->name, name))
969 return fn;
970
971 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
972 if (!strcmp(ll_merge_drv[i].name, name))
973 return &ll_merge_drv[i];
974
975 /* default to the 3-way */
976 return &ll_merge_drv[LL_TEXT_MERGE];
977 }
978
979 static const char *git_path_check_merge(const char *path)
980 {
981 static struct git_attr_check attr_merge_check;
982
983 if (!attr_merge_check.attr)
984 attr_merge_check.attr = git_attr("merge", 5);
985
986 if (git_checkattr(path, 1, &attr_merge_check))
987 return NULL;
988 return attr_merge_check.value;
989 }
990
991 static int ll_merge(mmbuffer_t *result_buf,
992 struct diff_filespec *o,
993 struct diff_filespec *a,
994 struct diff_filespec *b,
995 const char *branch1,
996 const char *branch2)
997 {
998 mmfile_t orig, src1, src2;
999 char *name1, *name2;
1000 int merge_status;
1001 const char *ll_driver_name;
1002 const struct ll_merge_driver *driver;
1003
1004 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1005 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1006
1007 fill_mm(o->sha1, &orig);
1008 fill_mm(a->sha1, &src1);
1009 fill_mm(b->sha1, &src2);
1010
1011 ll_driver_name = git_path_check_merge(a->path);
1012 driver = find_ll_merge_driver(ll_driver_name);
1013
1014 if (index_only && driver->recursive)
1015 driver = find_ll_merge_driver(driver->recursive);
1016 merge_status = driver->fn(driver, a->path,
1017 &orig, &src1, name1, &src2, name2,
1018 result_buf);
1019
1020 free(name1);
1021 free(name2);
1022 free(orig.ptr);
1023 free(src1.ptr);
1024 free(src2.ptr);
1025 return merge_status;
1026 }
1027
1028 static struct merge_file_info merge_file(struct diff_filespec *o,
1029 struct diff_filespec *a, struct diff_filespec *b,
1030 const char *branch1, const char *branch2)
1031 {
1032 struct merge_file_info result;
1033 result.merge = 0;
1034 result.clean = 1;
1035
1036 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1037 result.clean = 0;
1038 if (S_ISREG(a->mode)) {
1039 result.mode = a->mode;
1040 hashcpy(result.sha, a->sha1);
1041 } else {
1042 result.mode = b->mode;
1043 hashcpy(result.sha, b->sha1);
1044 }
1045 } else {
1046 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1047 result.merge = 1;
1048
1049 result.mode = a->mode == o->mode ? b->mode: a->mode;
1050
1051 if (sha_eq(a->sha1, o->sha1))
1052 hashcpy(result.sha, b->sha1);
1053 else if (sha_eq(b->sha1, o->sha1))
1054 hashcpy(result.sha, a->sha1);
1055 else if (S_ISREG(a->mode)) {
1056 mmbuffer_t result_buf;
1057 int merge_status;
1058
1059 merge_status = ll_merge(&result_buf, o, a, b,
1060 branch1, branch2);
1061
1062 if ((merge_status < 0) || !result_buf.ptr)
1063 die("Failed to execute internal merge");
1064
1065 if (write_sha1_file(result_buf.ptr, result_buf.size,
1066 blob_type, result.sha))
1067 die("Unable to add %s to database",
1068 a->path);
1069
1070 free(result_buf.ptr);
1071 result.clean = (merge_status == 0);
1072 } else {
1073 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1074 die("cannot merge modes?");
1075
1076 hashcpy(result.sha, a->sha1);
1077
1078 if (!sha_eq(a->sha1, b->sha1))
1079 result.clean = 0;
1080 }
1081 }
1082
1083 return result;
1084 }
1085
1086 static void conflict_rename_rename(struct rename *ren1,
1087 const char *branch1,
1088 struct rename *ren2,
1089 const char *branch2)
1090 {
1091 char *del[2];
1092 int delp = 0;
1093 const char *ren1_dst = ren1->pair->two->path;
1094 const char *ren2_dst = ren2->pair->two->path;
1095 const char *dst_name1 = ren1_dst;
1096 const char *dst_name2 = ren2_dst;
1097 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1098 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1099 output(1, "%s is a directory in %s added as %s instead",
1100 ren1_dst, branch2, dst_name1);
1101 remove_file(0, ren1_dst, 0);
1102 }
1103 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1104 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1105 output(1, "%s is a directory in %s added as %s instead",
1106 ren2_dst, branch1, dst_name2);
1107 remove_file(0, ren2_dst, 0);
1108 }
1109 if (index_only) {
1110 remove_file_from_cache(dst_name1);
1111 remove_file_from_cache(dst_name2);
1112 /*
1113 * Uncomment to leave the conflicting names in the resulting tree
1114 *
1115 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1116 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1117 */
1118 } else {
1119 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1120 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1121 }
1122 while (delp--)
1123 free(del[delp]);
1124 }
1125
1126 static void conflict_rename_dir(struct rename *ren1,
1127 const char *branch1)
1128 {
1129 char *new_path = unique_path(ren1->pair->two->path, branch1);
1130 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1131 remove_file(0, ren1->pair->two->path, 0);
1132 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1133 free(new_path);
1134 }
1135
1136 static void conflict_rename_rename_2(struct rename *ren1,
1137 const char *branch1,
1138 struct rename *ren2,
1139 const char *branch2)
1140 {
1141 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1142 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1143 output(1, "Renamed %s to %s and %s to %s instead",
1144 ren1->pair->one->path, new_path1,
1145 ren2->pair->one->path, new_path2);
1146 remove_file(0, ren1->pair->two->path, 0);
1147 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1148 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1149 free(new_path2);
1150 free(new_path1);
1151 }
1152
1153 static int process_renames(struct path_list *a_renames,
1154 struct path_list *b_renames,
1155 const char *a_branch,
1156 const char *b_branch)
1157 {
1158 int clean_merge = 1, i, j;
1159 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1160 const struct rename *sre;
1161
1162 for (i = 0; i < a_renames->nr; i++) {
1163 sre = a_renames->items[i].util;
1164 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1165 = sre->dst_entry;
1166 }
1167 for (i = 0; i < b_renames->nr; i++) {
1168 sre = b_renames->items[i].util;
1169 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1170 = sre->dst_entry;
1171 }
1172
1173 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1174 int compare;
1175 char *src;
1176 struct path_list *renames1, *renames2, *renames2Dst;
1177 struct rename *ren1 = NULL, *ren2 = NULL;
1178 const char *branch1, *branch2;
1179 const char *ren1_src, *ren1_dst;
1180
1181 if (i >= a_renames->nr) {
1182 compare = 1;
1183 ren2 = b_renames->items[j++].util;
1184 } else if (j >= b_renames->nr) {
1185 compare = -1;
1186 ren1 = a_renames->items[i++].util;
1187 } else {
1188 compare = strcmp(a_renames->items[i].path,
1189 b_renames->items[j].path);
1190 if (compare <= 0)
1191 ren1 = a_renames->items[i++].util;
1192 if (compare >= 0)
1193 ren2 = b_renames->items[j++].util;
1194 }
1195
1196 /* TODO: refactor, so that 1/2 are not needed */
1197 if (ren1) {
1198 renames1 = a_renames;
1199 renames2 = b_renames;
1200 renames2Dst = &b_by_dst;
1201 branch1 = a_branch;
1202 branch2 = b_branch;
1203 } else {
1204 struct rename *tmp;
1205 renames1 = b_renames;
1206 renames2 = a_renames;
1207 renames2Dst = &a_by_dst;
1208 branch1 = b_branch;
1209 branch2 = a_branch;
1210 tmp = ren2;
1211 ren2 = ren1;
1212 ren1 = tmp;
1213 }
1214 src = ren1->pair->one->path;
1215
1216 ren1->dst_entry->processed = 1;
1217 ren1->src_entry->processed = 1;
1218
1219 if (ren1->processed)
1220 continue;
1221 ren1->processed = 1;
1222
1223 ren1_src = ren1->pair->one->path;
1224 ren1_dst = ren1->pair->two->path;
1225
1226 if (ren2) {
1227 const char *ren2_src = ren2->pair->one->path;
1228 const char *ren2_dst = ren2->pair->two->path;
1229 /* Renamed in 1 and renamed in 2 */
1230 if (strcmp(ren1_src, ren2_src) != 0)
1231 die("ren1.src != ren2.src");
1232 ren2->dst_entry->processed = 1;
1233 ren2->processed = 1;
1234 if (strcmp(ren1_dst, ren2_dst) != 0) {
1235 clean_merge = 0;
1236 output(1, "CONFLICT (rename/rename): "
1237 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1238 "rename \"%s\"->\"%s\" in \"%s\"%s",
1239 src, ren1_dst, branch1,
1240 src, ren2_dst, branch2,
1241 index_only ? " (left unresolved)": "");
1242 if (index_only) {
1243 remove_file_from_cache(src);
1244 update_file(0, ren1->pair->one->sha1,
1245 ren1->pair->one->mode, src);
1246 }
1247 conflict_rename_rename(ren1, branch1, ren2, branch2);
1248 } else {
1249 struct merge_file_info mfi;
1250 remove_file(1, ren1_src, 1);
1251 mfi = merge_file(ren1->pair->one,
1252 ren1->pair->two,
1253 ren2->pair->two,
1254 branch1,
1255 branch2);
1256 if (mfi.merge || !mfi.clean)
1257 output(1, "Renamed %s->%s", src, ren1_dst);
1258
1259 if (mfi.merge)
1260 output(2, "Auto-merged %s", ren1_dst);
1261
1262 if (!mfi.clean) {
1263 output(1, "CONFLICT (content): merge conflict in %s",
1264 ren1_dst);
1265 clean_merge = 0;
1266
1267 if (!index_only)
1268 update_stages(ren1_dst,
1269 ren1->pair->one,
1270 ren1->pair->two,
1271 ren2->pair->two,
1272 1 /* clear */);
1273 }
1274 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1275 }
1276 } else {
1277 /* Renamed in 1, maybe changed in 2 */
1278 struct path_list_item *item;
1279 /* we only use sha1 and mode of these */
1280 struct diff_filespec src_other, dst_other;
1281 int try_merge, stage = a_renames == renames1 ? 3: 2;
1282
1283 remove_file(1, ren1_src, index_only || stage == 3);
1284
1285 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1286 src_other.mode = ren1->src_entry->stages[stage].mode;
1287 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1288 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1289
1290 try_merge = 0;
1291
1292 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1293 clean_merge = 0;
1294 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1295 " directory %s added in %s",
1296 ren1_src, ren1_dst, branch1,
1297 ren1_dst, branch2);
1298 conflict_rename_dir(ren1, branch1);
1299 } else if (sha_eq(src_other.sha1, null_sha1)) {
1300 clean_merge = 0;
1301 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1302 "and deleted in %s",
1303 ren1_src, ren1_dst, branch1,
1304 branch2);
1305 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1306 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1307 const char *new_path;
1308 clean_merge = 0;
1309 try_merge = 1;
1310 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1311 "%s added in %s",
1312 ren1_src, ren1_dst, branch1,
1313 ren1_dst, branch2);
1314 new_path = unique_path(ren1_dst, branch2);
1315 output(1, "Added as %s instead", new_path);
1316 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1317 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1318 ren2 = item->util;
1319 clean_merge = 0;
1320 ren2->processed = 1;
1321 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1322 "Renamed %s->%s in %s",
1323 ren1_src, ren1_dst, branch1,
1324 ren2->pair->one->path, ren2->pair->two->path, branch2);
1325 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1326 } else
1327 try_merge = 1;
1328
1329 if (try_merge) {
1330 struct diff_filespec *o, *a, *b;
1331 struct merge_file_info mfi;
1332 src_other.path = (char *)ren1_src;
1333
1334 o = ren1->pair->one;
1335 if (a_renames == renames1) {
1336 a = ren1->pair->two;
1337 b = &src_other;
1338 } else {
1339 b = ren1->pair->two;
1340 a = &src_other;
1341 }
1342 mfi = merge_file(o, a, b,
1343 a_branch, b_branch);
1344
1345 if (mfi.merge || !mfi.clean)
1346 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1347 if (mfi.merge)
1348 output(2, "Auto-merged %s", ren1_dst);
1349 if (!mfi.clean) {
1350 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1351 ren1_dst);
1352 clean_merge = 0;
1353
1354 if (!index_only)
1355 update_stages(ren1_dst,
1356 o, a, b, 1);
1357 }
1358 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1359 }
1360 }
1361 }
1362 path_list_clear(&a_by_dst, 0);
1363 path_list_clear(&b_by_dst, 0);
1364
1365 return clean_merge;
1366 }
1367
1368 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1369 {
1370 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1371 }
1372
1373 /* Per entry merge function */
1374 static int process_entry(const char *path, struct stage_data *entry,
1375 const char *branch1,
1376 const char *branch2)
1377 {
1378 /*
1379 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1380 print_index_entry("\tpath: ", entry);
1381 */
1382 int clean_merge = 1;
1383 unsigned o_mode = entry->stages[1].mode;
1384 unsigned a_mode = entry->stages[2].mode;
1385 unsigned b_mode = entry->stages[3].mode;
1386 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1387 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1388 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1389
1390 if (o_sha && (!a_sha || !b_sha)) {
1391 /* Case A: Deleted in one */
1392 if ((!a_sha && !b_sha) ||
1393 (sha_eq(a_sha, o_sha) && !b_sha) ||
1394 (!a_sha && sha_eq(b_sha, o_sha))) {
1395 /* Deleted in both or deleted in one and
1396 * unchanged in the other */
1397 if (a_sha)
1398 output(2, "Removed %s", path);
1399 /* do not touch working file if it did not exist */
1400 remove_file(1, path, !a_sha);
1401 } else {
1402 /* Deleted in one and changed in the other */
1403 clean_merge = 0;
1404 if (!a_sha) {
1405 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1406 "and modified in %s. Version %s of %s left in tree.",
1407 path, branch1,
1408 branch2, branch2, path);
1409 update_file(0, b_sha, b_mode, path);
1410 } else {
1411 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1412 "and modified in %s. Version %s of %s left in tree.",
1413 path, branch2,
1414 branch1, branch1, path);
1415 update_file(0, a_sha, a_mode, path);
1416 }
1417 }
1418
1419 } else if ((!o_sha && a_sha && !b_sha) ||
1420 (!o_sha && !a_sha && b_sha)) {
1421 /* Case B: Added in one. */
1422 const char *add_branch;
1423 const char *other_branch;
1424 unsigned mode;
1425 const unsigned char *sha;
1426 const char *conf;
1427
1428 if (a_sha) {
1429 add_branch = branch1;
1430 other_branch = branch2;
1431 mode = a_mode;
1432 sha = a_sha;
1433 conf = "file/directory";
1434 } else {
1435 add_branch = branch2;
1436 other_branch = branch1;
1437 mode = b_mode;
1438 sha = b_sha;
1439 conf = "directory/file";
1440 }
1441 if (path_list_has_path(&current_directory_set, path)) {
1442 const char *new_path = unique_path(path, add_branch);
1443 clean_merge = 0;
1444 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1445 "Added %s as %s",
1446 conf, path, other_branch, path, new_path);
1447 remove_file(0, path, 0);
1448 update_file(0, sha, mode, new_path);
1449 } else {
1450 output(2, "Added %s", path);
1451 update_file(1, sha, mode, path);
1452 }
1453 } else if (a_sha && b_sha) {
1454 /* Case C: Added in both (check for same permissions) and */
1455 /* case D: Modified in both, but differently. */
1456 const char *reason = "content";
1457 struct merge_file_info mfi;
1458 struct diff_filespec o, a, b;
1459
1460 if (!o_sha) {
1461 reason = "add/add";
1462 o_sha = (unsigned char *)null_sha1;
1463 }
1464 output(2, "Auto-merged %s", path);
1465 o.path = a.path = b.path = (char *)path;
1466 hashcpy(o.sha1, o_sha);
1467 o.mode = o_mode;
1468 hashcpy(a.sha1, a_sha);
1469 a.mode = a_mode;
1470 hashcpy(b.sha1, b_sha);
1471 b.mode = b_mode;
1472
1473 mfi = merge_file(&o, &a, &b,
1474 branch1, branch2);
1475
1476 if (mfi.clean)
1477 update_file(1, mfi.sha, mfi.mode, path);
1478 else {
1479 clean_merge = 0;
1480 output(1, "CONFLICT (%s): Merge conflict in %s",
1481 reason, path);
1482
1483 if (index_only)
1484 update_file(0, mfi.sha, mfi.mode, path);
1485 else
1486 update_file_flags(mfi.sha, mfi.mode, path,
1487 0 /* update_cache */, 1 /* update_working_directory */);
1488 }
1489 } else if (!o_sha && !a_sha && !b_sha) {
1490 /*
1491 * this entry was deleted altogether. a_mode == 0 means
1492 * we had that path and want to actively remove it.
1493 */
1494 remove_file(1, path, !a_mode);
1495 } else
1496 die("Fatal merge failure, shouldn't happen.");
1497
1498 return clean_merge;
1499 }
1500
1501 static int merge_trees(struct tree *head,
1502 struct tree *merge,
1503 struct tree *common,
1504 const char *branch1,
1505 const char *branch2,
1506 struct tree **result)
1507 {
1508 int code, clean;
1509
1510 if (subtree_merge) {
1511 merge = shift_tree_object(head, merge);
1512 common = shift_tree_object(head, common);
1513 }
1514
1515 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1516 output(0, "Already uptodate!");
1517 *result = head;
1518 return 1;
1519 }
1520
1521 code = git_merge_trees(index_only, common, head, merge);
1522
1523 if (code != 0)
1524 die("merging of trees %s and %s failed",
1525 sha1_to_hex(head->object.sha1),
1526 sha1_to_hex(merge->object.sha1));
1527
1528 if (unmerged_index()) {
1529 struct path_list *entries, *re_head, *re_merge;
1530 int i;
1531 path_list_clear(&current_file_set, 1);
1532 path_list_clear(&current_directory_set, 1);
1533 get_files_dirs(head);
1534 get_files_dirs(merge);
1535
1536 entries = get_unmerged();
1537 re_head = get_renames(head, common, head, merge, entries);
1538 re_merge = get_renames(merge, common, head, merge, entries);
1539 clean = process_renames(re_head, re_merge,
1540 branch1, branch2);
1541 for (i = 0; i < entries->nr; i++) {
1542 const char *path = entries->items[i].path;
1543 struct stage_data *e = entries->items[i].util;
1544 if (!e->processed
1545 && !process_entry(path, e, branch1, branch2))
1546 clean = 0;
1547 }
1548
1549 path_list_clear(re_merge, 0);
1550 path_list_clear(re_head, 0);
1551 path_list_clear(entries, 1);
1552
1553 }
1554 else
1555 clean = 1;
1556
1557 if (index_only)
1558 *result = git_write_tree();
1559
1560 return clean;
1561 }
1562
1563 static struct commit_list *reverse_commit_list(struct commit_list *list)
1564 {
1565 struct commit_list *next = NULL, *current, *backup;
1566 for (current = list; current; current = backup) {
1567 backup = current->next;
1568 current->next = next;
1569 next = current;
1570 }
1571 return next;
1572 }
1573
1574 /*
1575 * Merge the commits h1 and h2, return the resulting virtual
1576 * commit object and a flag indicating the cleanness of the merge.
1577 */
1578 static int merge(struct commit *h1,
1579 struct commit *h2,
1580 const char *branch1,
1581 const char *branch2,
1582 struct commit_list *ca,
1583 struct commit **result)
1584 {
1585 struct commit_list *iter;
1586 struct commit *merged_common_ancestors;
1587 struct tree *mrtree;
1588 int clean;
1589
1590 if (show(4)) {
1591 output(4, "Merging:");
1592 output_commit_title(h1);
1593 output_commit_title(h2);
1594 }
1595
1596 if (!ca) {
1597 ca = get_merge_bases(h1, h2, 1);
1598 ca = reverse_commit_list(ca);
1599 }
1600
1601 if (show(5)) {
1602 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1603 for (iter = ca; iter; iter = iter->next)
1604 output_commit_title(iter->item);
1605 }
1606
1607 merged_common_ancestors = pop_commit(&ca);
1608 if (merged_common_ancestors == NULL) {
1609 /* if there is no common ancestor, make an empty tree */
1610 struct tree *tree = xcalloc(1, sizeof(struct tree));
1611
1612 tree->object.parsed = 1;
1613 tree->object.type = OBJ_TREE;
1614 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1615 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1616 }
1617
1618 for (iter = ca; iter; iter = iter->next) {
1619 call_depth++;
1620 /*
1621 * When the merge fails, the result contains files
1622 * with conflict markers. The cleanness flag is
1623 * ignored, it was never actually used, as result of
1624 * merge_trees has always overwritten it: the committed
1625 * "conflicts" were already resolved.
1626 */
1627 discard_cache();
1628 merge(merged_common_ancestors, iter->item,
1629 "Temporary merge branch 1",
1630 "Temporary merge branch 2",
1631 NULL,
1632 &merged_common_ancestors);
1633 call_depth--;
1634
1635 if (!merged_common_ancestors)
1636 die("merge returned no commit");
1637 }
1638
1639 discard_cache();
1640 if (!call_depth) {
1641 read_cache();
1642 index_only = 0;
1643 } else
1644 index_only = 1;
1645
1646 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1647 branch1, branch2, &mrtree);
1648
1649 if (index_only) {
1650 *result = make_virtual_commit(mrtree, "merged tree");
1651 commit_list_insert(h1, &(*result)->parents);
1652 commit_list_insert(h2, &(*result)->parents->next);
1653 }
1654 flush_output();
1655 return clean;
1656 }
1657
1658 static const char *better_branch_name(const char *branch)
1659 {
1660 static char githead_env[8 + 40 + 1];
1661 char *name;
1662
1663 if (strlen(branch) != 40)
1664 return branch;
1665 sprintf(githead_env, "GITHEAD_%s", branch);
1666 name = getenv(githead_env);
1667 return name ? name : branch;
1668 }
1669
1670 static struct commit *get_ref(const char *ref)
1671 {
1672 unsigned char sha1[20];
1673 struct object *object;
1674
1675 if (get_sha1(ref, sha1))
1676 die("Could not resolve ref '%s'", ref);
1677 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1678 if (object->type == OBJ_TREE)
1679 return make_virtual_commit((struct tree*)object,
1680 better_branch_name(ref));
1681 if (object->type != OBJ_COMMIT)
1682 return NULL;
1683 if (parse_commit((struct commit *)object))
1684 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1685 return (struct commit *)object;
1686 }
1687
1688 static int merge_config(const char *var, const char *value)
1689 {
1690 if (!strcasecmp(var, "merge.verbosity")) {
1691 verbosity = git_config_int(var, value);
1692 return 0;
1693 }
1694 return git_default_config(var, value);
1695 }
1696
1697 int main(int argc, char *argv[])
1698 {
1699 static const char *bases[20];
1700 static unsigned bases_count = 0;
1701 int i, clean;
1702 const char *branch1, *branch2;
1703 struct commit *result, *h1, *h2;
1704 struct commit_list *ca = NULL;
1705 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1706 int index_fd;
1707
1708 if (argv[0]) {
1709 int namelen = strlen(argv[0]);
1710 if (8 < namelen &&
1711 !strcmp(argv[0] + namelen - 8, "-subtree"))
1712 subtree_merge = 1;
1713 }
1714
1715 git_config(merge_config);
1716 if (getenv("GIT_MERGE_VERBOSITY"))
1717 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1718
1719 if (argc < 4)
1720 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1721
1722 for (i = 1; i < argc; ++i) {
1723 if (!strcmp(argv[i], "--"))
1724 break;
1725 if (bases_count < sizeof(bases)/sizeof(*bases))
1726 bases[bases_count++] = argv[i];
1727 }
1728 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1729 die("Not handling anything other than two heads merge.");
1730 if (verbosity >= 5)
1731 buffer_output = 0;
1732
1733 branch1 = argv[++i];
1734 branch2 = argv[++i];
1735
1736 h1 = get_ref(branch1);
1737 h2 = get_ref(branch2);
1738
1739 branch1 = better_branch_name(branch1);
1740 branch2 = better_branch_name(branch2);
1741
1742 if (show(3))
1743 printf("Merging %s with %s\n", branch1, branch2);
1744
1745 index_fd = hold_locked_index(lock, 1);
1746
1747 for (i = 0; i < bases_count; i++) {
1748 struct commit *ancestor = get_ref(bases[i]);
1749 ca = commit_list_insert(ancestor, &ca);
1750 }
1751 clean = merge(h1, h2, branch1, branch2, ca, &result);
1752
1753 if (active_cache_changed &&
1754 (write_cache(index_fd, active_cache, active_nr) ||
1755 close(index_fd) || commit_locked_index(lock)))
1756 die ("unable to write %s", get_index_file());
1757
1758 return clean ? 0: 1;
1759 }