merge-recursive: do not barf on "to be removed" entries.
[git] / merge-recursive.c
1 /*
2  * Recursive Merge algorithm stolen from git-merge-recursive.py by
3  * Fredrik Kuivinen.
4  * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5  */
6 #include "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "tree-walk.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "run-command.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18
19 static int subtree_merge;
20
21 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
22 {
23         unsigned char shifted[20];
24
25         /*
26          * NEEDSWORK: this limits the recursion depth to hardcoded
27          * value '2' to avoid excessive overhead.
28          */
29         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
30         if (!hashcmp(two->object.sha1, shifted))
31                 return two;
32         return lookup_tree(shifted);
33 }
34
35 /*
36  * A virtual commit has
37  * - (const char *)commit->util set to the name, and
38  * - *(int *)commit->object.sha1 set to the virtual id.
39  */
40
41 static unsigned commit_list_count(const struct commit_list *l)
42 {
43         unsigned c = 0;
44         for (; l; l = l->next )
45                 c++;
46         return c;
47 }
48
49 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
50 {
51         struct commit *commit = xcalloc(1, sizeof(struct commit));
52         static unsigned virtual_id = 1;
53         commit->tree = tree;
54         commit->util = (void*)comment;
55         *(int*)commit->object.sha1 = virtual_id++;
56         /* avoid warnings */
57         commit->object.parsed = 1;
58         return commit;
59 }
60
61 /*
62  * Since we use get_tree_entry(), which does not put the read object into
63  * the object pool, we cannot rely on a == b.
64  */
65 static int sha_eq(const unsigned char *a, const unsigned char *b)
66 {
67         if (!a && !b)
68                 return 2;
69         return a && b && hashcmp(a, b) == 0;
70 }
71
72 /*
73  * Since we want to write the index eventually, we cannot reuse the index
74  * for these (temporary) data.
75  */
76 struct stage_data
77 {
78         struct
79         {
80                 unsigned mode;
81                 unsigned char sha[20];
82         } stages[4];
83         unsigned processed:1;
84 };
85
86 struct output_buffer
87 {
88         struct output_buffer *next;
89         char *str;
90 };
91
92 static struct path_list current_file_set = {NULL, 0, 0, 1};
93 static struct path_list current_directory_set = {NULL, 0, 0, 1};
94
95 static int call_depth = 0;
96 static int verbosity = 2;
97 static int buffer_output = 1;
98 static int do_progress = 1;
99 static unsigned last_percent;
100 static unsigned merged_cnt;
101 static unsigned total_cnt;
102 static volatile sig_atomic_t progress_update;
103 static struct output_buffer *output_list, *output_end;
104
105 static int show (int v)
106 {
107         return (!call_depth && verbosity >= v) || verbosity >= 5;
108 }
109
110 static void output(int v, const char *fmt, ...)
111 {
112         va_list args;
113         va_start(args, fmt);
114         if (buffer_output && show(v)) {
115                 struct output_buffer *b = xmalloc(sizeof(*b));
116                 nfvasprintf(&b->str, fmt, args);
117                 b->next = NULL;
118                 if (output_end)
119                         output_end->next = b;
120                 else
121                         output_list = b;
122                 output_end = b;
123         } else if (show(v)) {
124                 int i;
125                 for (i = call_depth; i--;)
126                         fputs("  ", stdout);
127                 vfprintf(stdout, fmt, args);
128                 fputc('\n', stdout);
129         }
130         va_end(args);
131 }
132
133 static void flush_output()
134 {
135         struct output_buffer *b, *n;
136         for (b = output_list; b; b = n) {
137                 int i;
138                 for (i = call_depth; i--;)
139                         fputs("  ", stdout);
140                 fputs(b->str, stdout);
141                 fputc('\n', stdout);
142                 n = b->next;
143                 free(b->str);
144                 free(b);
145         }
146         output_list = NULL;
147         output_end = NULL;
148 }
149
150 static void output_commit_title(struct commit *commit)
151 {
152         int i;
153         flush_output();
154         for (i = call_depth; i--;)
155                 fputs("  ", stdout);
156         if (commit->util)
157                 printf("virtual %s\n", (char *)commit->util);
158         else {
159                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
160                 if (parse_commit(commit) != 0)
161                         printf("(bad commit)\n");
162                 else {
163                         const char *s;
164                         int len;
165                         for (s = commit->buffer; *s; s++)
166                                 if (*s == '\n' && s[1] == '\n') {
167                                         s += 2;
168                                         break;
169                                 }
170                         for (len = 0; s[len] && '\n' != s[len]; len++)
171                                 ; /* do nothing */
172                         printf("%.*s\n", len, s);
173                 }
174         }
175 }
176
177 static void progress_interval(int signum)
178 {
179         progress_update = 1;
180 }
181
182 static void setup_progress_signal(void)
183 {
184         struct sigaction sa;
185         struct itimerval v;
186
187         memset(&sa, 0, sizeof(sa));
188         sa.sa_handler = progress_interval;
189         sigemptyset(&sa.sa_mask);
190         sa.sa_flags = SA_RESTART;
191         sigaction(SIGALRM, &sa, NULL);
192
193         v.it_interval.tv_sec = 1;
194         v.it_interval.tv_usec = 0;
195         v.it_value = v.it_interval;
196         setitimer(ITIMER_REAL, &v, NULL);
197 }
198
199 static void display_progress()
200 {
201         unsigned percent = total_cnt ? merged_cnt * 100 / total_cnt : 0;
202         if (progress_update || percent != last_percent) {
203                 fprintf(stderr, "%4u%% (%u/%u) done\r",
204                         percent, merged_cnt, total_cnt);
205                 progress_update = 0;
206                 last_percent = percent;
207         }
208 }
209
210 static struct cache_entry *make_cache_entry(unsigned int mode,
211                 const unsigned char *sha1, const char *path, int stage, int refresh)
212 {
213         int size, len;
214         struct cache_entry *ce;
215
216         if (!verify_path(path))
217                 return NULL;
218
219         len = strlen(path);
220         size = cache_entry_size(len);
221         ce = xcalloc(1, size);
222
223         hashcpy(ce->sha1, sha1);
224         memcpy(ce->name, path, len);
225         ce->ce_flags = create_ce_flags(len, stage);
226         ce->ce_mode = create_ce_mode(mode);
227
228         if (refresh)
229                 return refresh_cache_entry(ce, 0);
230
231         return ce;
232 }
233
234 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
235                 const char *path, int stage, int refresh, int options)
236 {
237         struct cache_entry *ce;
238         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
239         if (!ce)
240                 return error("addinfo_cache failed for path '%s'", path);
241         return add_cache_entry(ce, options);
242 }
243
244 /*
245  * This is a global variable which is used in a number of places but
246  * only written to in the 'merge' function.
247  *
248  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
249  *                       don't update the working directory.
250  *               0    => Leave unmerged entries in the cache and update
251  *                       the working directory.
252  */
253 static int index_only = 0;
254
255 static int git_merge_trees(int index_only,
256                            struct tree *common,
257                            struct tree *head,
258                            struct tree *merge)
259 {
260         int rc;
261         struct object_list *trees = NULL;
262         struct unpack_trees_options opts;
263
264         memset(&opts, 0, sizeof(opts));
265         if (index_only)
266                 opts.index_only = 1;
267         else
268                 opts.update = 1;
269         opts.merge = 1;
270         opts.head_idx = 2;
271         opts.fn = threeway_merge;
272
273         object_list_append(&common->object, &trees);
274         object_list_append(&head->object, &trees);
275         object_list_append(&merge->object, &trees);
276
277         rc = unpack_trees(trees, &opts);
278         cache_tree_free(&active_cache_tree);
279         return rc;
280 }
281
282 static int unmerged_index(void)
283 {
284         int i;
285         for (i = 0; i < active_nr; i++) {
286                 struct cache_entry *ce = active_cache[i];
287                 if (ce_stage(ce))
288                         return 1;
289         }
290         return 0;
291 }
292
293 static struct tree *git_write_tree(void)
294 {
295         struct tree *result = NULL;
296
297         if (unmerged_index()) {
298                 int i;
299                 output(0, "There are unmerged index entries:");
300                 for (i = 0; i < active_nr; i++) {
301                         struct cache_entry *ce = active_cache[i];
302                         if (ce_stage(ce))
303                                 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
304                 }
305                 return NULL;
306         }
307
308         if (!active_cache_tree)
309                 active_cache_tree = cache_tree();
310
311         if (!cache_tree_fully_valid(active_cache_tree) &&
312             cache_tree_update(active_cache_tree,
313                               active_cache, active_nr, 0, 0) < 0)
314                 die("error building trees");
315
316         result = lookup_tree(active_cache_tree->sha1);
317
318         return result;
319 }
320
321 static int save_files_dirs(const unsigned char *sha1,
322                 const char *base, int baselen, const char *path,
323                 unsigned int mode, int stage)
324 {
325         int len = strlen(path);
326         char *newpath = xmalloc(baselen + len + 1);
327         memcpy(newpath, base, baselen);
328         memcpy(newpath + baselen, path, len);
329         newpath[baselen + len] = '\0';
330
331         if (S_ISDIR(mode))
332                 path_list_insert(newpath, &current_directory_set);
333         else
334                 path_list_insert(newpath, &current_file_set);
335         free(newpath);
336
337         return READ_TREE_RECURSIVE;
338 }
339
340 static int get_files_dirs(struct tree *tree)
341 {
342         int n;
343         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
344                 return 0;
345         n = current_file_set.nr + current_directory_set.nr;
346         return n;
347 }
348
349 /*
350  * Returns a index_entry instance which doesn't have to correspond to
351  * a real cache entry in Git's index.
352  */
353 static struct stage_data *insert_stage_data(const char *path,
354                 struct tree *o, struct tree *a, struct tree *b,
355                 struct path_list *entries)
356 {
357         struct path_list_item *item;
358         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
359         get_tree_entry(o->object.sha1, path,
360                         e->stages[1].sha, &e->stages[1].mode);
361         get_tree_entry(a->object.sha1, path,
362                         e->stages[2].sha, &e->stages[2].mode);
363         get_tree_entry(b->object.sha1, path,
364                         e->stages[3].sha, &e->stages[3].mode);
365         item = path_list_insert(path, entries);
366         item->util = e;
367         return e;
368 }
369
370 /*
371  * Create a dictionary mapping file names to stage_data objects. The
372  * dictionary contains one entry for every path with a non-zero stage entry.
373  */
374 static struct path_list *get_unmerged(void)
375 {
376         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
377         int i;
378
379         unmerged->strdup_paths = 1;
380         total_cnt += active_nr;
381
382         for (i = 0; i < active_nr; i++, merged_cnt++) {
383                 struct path_list_item *item;
384                 struct stage_data *e;
385                 struct cache_entry *ce = active_cache[i];
386                 if (do_progress)
387                         display_progress();
388                 if (!ce_stage(ce))
389                         continue;
390
391                 item = path_list_lookup(ce->name, unmerged);
392                 if (!item) {
393                         item = path_list_insert(ce->name, unmerged);
394                         item->util = xcalloc(1, sizeof(struct stage_data));
395                 }
396                 e = item->util;
397                 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
398                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
399         }
400
401         return unmerged;
402 }
403
404 struct rename
405 {
406         struct diff_filepair *pair;
407         struct stage_data *src_entry;
408         struct stage_data *dst_entry;
409         unsigned processed:1;
410 };
411
412 /*
413  * Get information of all renames which occurred between 'o_tree' and
414  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
415  * 'b_tree') to be able to associate the correct cache entries with
416  * the rename information. 'tree' is always equal to either a_tree or b_tree.
417  */
418 static struct path_list *get_renames(struct tree *tree,
419                                         struct tree *o_tree,
420                                         struct tree *a_tree,
421                                         struct tree *b_tree,
422                                         struct path_list *entries)
423 {
424         int i;
425         struct path_list *renames;
426         struct diff_options opts;
427
428         renames = xcalloc(1, sizeof(struct path_list));
429         diff_setup(&opts);
430         opts.recursive = 1;
431         opts.detect_rename = DIFF_DETECT_RENAME;
432         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
433         if (diff_setup_done(&opts) < 0)
434                 die("diff setup failed");
435         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
436         diffcore_std(&opts);
437         for (i = 0; i < diff_queued_diff.nr; ++i) {
438                 struct path_list_item *item;
439                 struct rename *re;
440                 struct diff_filepair *pair = diff_queued_diff.queue[i];
441                 if (pair->status != 'R') {
442                         diff_free_filepair(pair);
443                         continue;
444                 }
445                 re = xmalloc(sizeof(*re));
446                 re->processed = 0;
447                 re->pair = pair;
448                 item = path_list_lookup(re->pair->one->path, entries);
449                 if (!item)
450                         re->src_entry = insert_stage_data(re->pair->one->path,
451                                         o_tree, a_tree, b_tree, entries);
452                 else
453                         re->src_entry = item->util;
454
455                 item = path_list_lookup(re->pair->two->path, entries);
456                 if (!item)
457                         re->dst_entry = insert_stage_data(re->pair->two->path,
458                                         o_tree, a_tree, b_tree, entries);
459                 else
460                         re->dst_entry = item->util;
461                 item = path_list_insert(pair->one->path, renames);
462                 item->util = re;
463         }
464         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
465         diff_queued_diff.nr = 0;
466         diff_flush(&opts);
467         return renames;
468 }
469
470 static int update_stages(const char *path, struct diff_filespec *o,
471                          struct diff_filespec *a, struct diff_filespec *b,
472                          int clear)
473 {
474         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
475         if (clear)
476                 if (remove_file_from_cache(path))
477                         return -1;
478         if (o)
479                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
480                         return -1;
481         if (a)
482                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
483                         return -1;
484         if (b)
485                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
486                         return -1;
487         return 0;
488 }
489
490 static int remove_path(const char *name)
491 {
492         int ret, len;
493         char *slash, *dirs;
494
495         ret = unlink(name);
496         if (ret)
497                 return ret;
498         len = strlen(name);
499         dirs = xmalloc(len+1);
500         memcpy(dirs, name, len);
501         dirs[len] = '\0';
502         while ((slash = strrchr(name, '/'))) {
503                 *slash = '\0';
504                 len = slash - name;
505                 if (rmdir(name) != 0)
506                         break;
507         }
508         free(dirs);
509         return ret;
510 }
511
512 static int remove_file(int clean, const char *path, int no_wd)
513 {
514         int update_cache = index_only || clean;
515         int update_working_directory = !index_only && !no_wd;
516
517         if (update_cache) {
518                 if (remove_file_from_cache(path))
519                         return -1;
520         }
521         if (update_working_directory) {
522                 unlink(path);
523                 if (errno != ENOENT || errno != EISDIR)
524                         return -1;
525                 remove_path(path);
526         }
527         return 0;
528 }
529
530 static char *unique_path(const char *path, const char *branch)
531 {
532         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
533         int suffix = 0;
534         struct stat st;
535         char *p = newpath + strlen(path);
536         strcpy(newpath, path);
537         *(p++) = '~';
538         strcpy(p, branch);
539         for (; *p; ++p)
540                 if ('/' == *p)
541                         *p = '_';
542         while (path_list_has_path(&current_file_set, newpath) ||
543                path_list_has_path(&current_directory_set, newpath) ||
544                lstat(newpath, &st) == 0)
545                 sprintf(p, "_%d", suffix++);
546
547         path_list_insert(newpath, &current_file_set);
548         return newpath;
549 }
550
551 static int mkdir_p(const char *path, unsigned long mode)
552 {
553         /* path points to cache entries, so xstrdup before messing with it */
554         char *buf = xstrdup(path);
555         int result = safe_create_leading_directories(buf);
556         free(buf);
557         return result;
558 }
559
560 static void flush_buffer(int fd, const char *buf, unsigned long size)
561 {
562         while (size > 0) {
563                 long ret = write_in_full(fd, buf, size);
564                 if (ret < 0) {
565                         /* Ignore epipe */
566                         if (errno == EPIPE)
567                                 break;
568                         die("merge-recursive: %s", strerror(errno));
569                 } else if (!ret) {
570                         die("merge-recursive: disk full?");
571                 }
572                 size -= ret;
573                 buf += ret;
574         }
575 }
576
577 static void update_file_flags(const unsigned char *sha,
578                               unsigned mode,
579                               const char *path,
580                               int update_cache,
581                               int update_wd)
582 {
583         if (index_only)
584                 update_wd = 0;
585
586         if (update_wd) {
587                 enum object_type type;
588                 void *buf;
589                 unsigned long size;
590
591                 buf = read_sha1_file(sha, &type, &size);
592                 if (!buf)
593                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
594                 if (type != OBJ_BLOB)
595                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
596
597                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
598                         int fd;
599                         if (mkdir_p(path, 0777))
600                                 die("failed to create path %s: %s", path, strerror(errno));
601                         unlink(path);
602                         if (mode & 0100)
603                                 mode = 0777;
604                         else
605                                 mode = 0666;
606                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
607                         if (fd < 0)
608                                 die("failed to open %s: %s", path, strerror(errno));
609                         flush_buffer(fd, buf, size);
610                         close(fd);
611                 } else if (S_ISLNK(mode)) {
612                         char *lnk = xmalloc(size + 1);
613                         memcpy(lnk, buf, size);
614                         lnk[size] = '\0';
615                         mkdir_p(path, 0777);
616                         unlink(path);
617                         symlink(lnk, path);
618                         free(lnk);
619                 } else
620                         die("do not know what to do with %06o %s '%s'",
621                             mode, sha1_to_hex(sha), path);
622         }
623         if (update_cache)
624                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
625 }
626
627 static void update_file(int clean,
628                         const unsigned char *sha,
629                         unsigned mode,
630                         const char *path)
631 {
632         update_file_flags(sha, mode, path, index_only || clean, !index_only);
633 }
634
635 /* Low level file merging, update and removal */
636
637 struct merge_file_info
638 {
639         unsigned char sha[20];
640         unsigned mode;
641         unsigned clean:1,
642                  merge:1;
643 };
644
645 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
646 {
647         unsigned long size;
648         enum object_type type;
649
650         if (!hashcmp(sha1, null_sha1)) {
651                 mm->ptr = xstrdup("");
652                 mm->size = 0;
653                 return;
654         }
655
656         mm->ptr = read_sha1_file(sha1, &type, &size);
657         if (!mm->ptr || type != OBJ_BLOB)
658                 die("unable to read blob object %s", sha1_to_hex(sha1));
659         mm->size = size;
660 }
661
662 static struct merge_file_info merge_file(struct diff_filespec *o,
663                 struct diff_filespec *a, struct diff_filespec *b,
664                 const char *branch1, const char *branch2)
665 {
666         struct merge_file_info result;
667         result.merge = 0;
668         result.clean = 1;
669
670         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
671                 result.clean = 0;
672                 if (S_ISREG(a->mode)) {
673                         result.mode = a->mode;
674                         hashcpy(result.sha, a->sha1);
675                 } else {
676                         result.mode = b->mode;
677                         hashcpy(result.sha, b->sha1);
678                 }
679         } else {
680                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
681                         result.merge = 1;
682
683                 result.mode = a->mode == o->mode ? b->mode: a->mode;
684
685                 if (sha_eq(a->sha1, o->sha1))
686                         hashcpy(result.sha, b->sha1);
687                 else if (sha_eq(b->sha1, o->sha1))
688                         hashcpy(result.sha, a->sha1);
689                 else if (S_ISREG(a->mode)) {
690                         mmfile_t orig, src1, src2;
691                         mmbuffer_t result_buf;
692                         xpparam_t xpp;
693                         char *name1, *name2;
694                         int merge_status;
695
696                         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
697                         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
698
699                         fill_mm(o->sha1, &orig);
700                         fill_mm(a->sha1, &src1);
701                         fill_mm(b->sha1, &src2);
702
703                         memset(&xpp, 0, sizeof(xpp));
704                         merge_status = xdl_merge(&orig,
705                                                  &src1, name1,
706                                                  &src2, name2,
707                                                  &xpp, XDL_MERGE_ZEALOUS,
708                                                  &result_buf);
709                         free(name1);
710                         free(name2);
711                         free(orig.ptr);
712                         free(src1.ptr);
713                         free(src2.ptr);
714
715                         if ((merge_status < 0) || !result_buf.ptr)
716                                 die("Failed to execute internal merge");
717
718                         if (write_sha1_file(result_buf.ptr, result_buf.size,
719                                             blob_type, result.sha))
720                                 die("Unable to add %s to database",
721                                     a->path);
722
723                         free(result_buf.ptr);
724                         result.clean = (merge_status == 0);
725                 } else {
726                         if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
727                                 die("cannot merge modes?");
728
729                         hashcpy(result.sha, a->sha1);
730
731                         if (!sha_eq(a->sha1, b->sha1))
732                                 result.clean = 0;
733                 }
734         }
735
736         return result;
737 }
738
739 static void conflict_rename_rename(struct rename *ren1,
740                                    const char *branch1,
741                                    struct rename *ren2,
742                                    const char *branch2)
743 {
744         char *del[2];
745         int delp = 0;
746         const char *ren1_dst = ren1->pair->two->path;
747         const char *ren2_dst = ren2->pair->two->path;
748         const char *dst_name1 = ren1_dst;
749         const char *dst_name2 = ren2_dst;
750         if (path_list_has_path(&current_directory_set, ren1_dst)) {
751                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
752                 output(1, "%s is a directory in %s added as %s instead",
753                        ren1_dst, branch2, dst_name1);
754                 remove_file(0, ren1_dst, 0);
755         }
756         if (path_list_has_path(&current_directory_set, ren2_dst)) {
757                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
758                 output(1, "%s is a directory in %s added as %s instead",
759                        ren2_dst, branch1, dst_name2);
760                 remove_file(0, ren2_dst, 0);
761         }
762         if (index_only) {
763                 remove_file_from_cache(dst_name1);
764                 remove_file_from_cache(dst_name2);
765                 /*
766                  * Uncomment to leave the conflicting names in the resulting tree
767                  *
768                  * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
769                  * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
770                  */
771         } else {
772                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
773                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
774         }
775         while (delp--)
776                 free(del[delp]);
777 }
778
779 static void conflict_rename_dir(struct rename *ren1,
780                                 const char *branch1)
781 {
782         char *new_path = unique_path(ren1->pair->two->path, branch1);
783         output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
784         remove_file(0, ren1->pair->two->path, 0);
785         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
786         free(new_path);
787 }
788
789 static void conflict_rename_rename_2(struct rename *ren1,
790                                      const char *branch1,
791                                      struct rename *ren2,
792                                      const char *branch2)
793 {
794         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
795         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
796         output(1, "Renamed %s to %s and %s to %s instead",
797                ren1->pair->one->path, new_path1,
798                ren2->pair->one->path, new_path2);
799         remove_file(0, ren1->pair->two->path, 0);
800         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
801         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
802         free(new_path2);
803         free(new_path1);
804 }
805
806 static int process_renames(struct path_list *a_renames,
807                            struct path_list *b_renames,
808                            const char *a_branch,
809                            const char *b_branch)
810 {
811         int clean_merge = 1, i, j;
812         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
813         const struct rename *sre;
814
815         for (i = 0; i < a_renames->nr; i++) {
816                 sre = a_renames->items[i].util;
817                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
818                         = sre->dst_entry;
819         }
820         for (i = 0; i < b_renames->nr; i++) {
821                 sre = b_renames->items[i].util;
822                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
823                         = sre->dst_entry;
824         }
825
826         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
827                 int compare;
828                 char *src;
829                 struct path_list *renames1, *renames2, *renames2Dst;
830                 struct rename *ren1 = NULL, *ren2 = NULL;
831                 const char *branch1, *branch2;
832                 const char *ren1_src, *ren1_dst;
833
834                 if (i >= a_renames->nr) {
835                         compare = 1;
836                         ren2 = b_renames->items[j++].util;
837                 } else if (j >= b_renames->nr) {
838                         compare = -1;
839                         ren1 = a_renames->items[i++].util;
840                 } else {
841                         compare = strcmp(a_renames->items[i].path,
842                                         b_renames->items[j].path);
843                         if (compare <= 0)
844                                 ren1 = a_renames->items[i++].util;
845                         if (compare >= 0)
846                                 ren2 = b_renames->items[j++].util;
847                 }
848
849                 /* TODO: refactor, so that 1/2 are not needed */
850                 if (ren1) {
851                         renames1 = a_renames;
852                         renames2 = b_renames;
853                         renames2Dst = &b_by_dst;
854                         branch1 = a_branch;
855                         branch2 = b_branch;
856                 } else {
857                         struct rename *tmp;
858                         renames1 = b_renames;
859                         renames2 = a_renames;
860                         renames2Dst = &a_by_dst;
861                         branch1 = b_branch;
862                         branch2 = a_branch;
863                         tmp = ren2;
864                         ren2 = ren1;
865                         ren1 = tmp;
866                 }
867                 src = ren1->pair->one->path;
868
869                 ren1->dst_entry->processed = 1;
870                 ren1->src_entry->processed = 1;
871
872                 if (ren1->processed)
873                         continue;
874                 ren1->processed = 1;
875
876                 ren1_src = ren1->pair->one->path;
877                 ren1_dst = ren1->pair->two->path;
878
879                 if (ren2) {
880                         const char *ren2_src = ren2->pair->one->path;
881                         const char *ren2_dst = ren2->pair->two->path;
882                         /* Renamed in 1 and renamed in 2 */
883                         if (strcmp(ren1_src, ren2_src) != 0)
884                                 die("ren1.src != ren2.src");
885                         ren2->dst_entry->processed = 1;
886                         ren2->processed = 1;
887                         if (strcmp(ren1_dst, ren2_dst) != 0) {
888                                 clean_merge = 0;
889                                 output(1, "CONFLICT (rename/rename): "
890                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
891                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
892                                        src, ren1_dst, branch1,
893                                        src, ren2_dst, branch2,
894                                        index_only ? " (left unresolved)": "");
895                                 if (index_only) {
896                                         remove_file_from_cache(src);
897                                         update_file(0, ren1->pair->one->sha1,
898                                                     ren1->pair->one->mode, src);
899                                 }
900                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
901                         } else {
902                                 struct merge_file_info mfi;
903                                 remove_file(1, ren1_src, 1);
904                                 mfi = merge_file(ren1->pair->one,
905                                                  ren1->pair->two,
906                                                  ren2->pair->two,
907                                                  branch1,
908                                                  branch2);
909                                 if (mfi.merge || !mfi.clean)
910                                         output(1, "Renamed %s->%s", src, ren1_dst);
911
912                                 if (mfi.merge)
913                                         output(2, "Auto-merged %s", ren1_dst);
914
915                                 if (!mfi.clean) {
916                                         output(1, "CONFLICT (content): merge conflict in %s",
917                                                ren1_dst);
918                                         clean_merge = 0;
919
920                                         if (!index_only)
921                                                 update_stages(ren1_dst,
922                                                               ren1->pair->one,
923                                                               ren1->pair->two,
924                                                               ren2->pair->two,
925                                                               1 /* clear */);
926                                 }
927                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
928                         }
929                 } else {
930                         /* Renamed in 1, maybe changed in 2 */
931                         struct path_list_item *item;
932                         /* we only use sha1 and mode of these */
933                         struct diff_filespec src_other, dst_other;
934                         int try_merge, stage = a_renames == renames1 ? 3: 2;
935
936                         remove_file(1, ren1_src, index_only || stage == 3);
937
938                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
939                         src_other.mode = ren1->src_entry->stages[stage].mode;
940                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
941                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
942
943                         try_merge = 0;
944
945                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
946                                 clean_merge = 0;
947                                 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
948                                        " directory %s added in %s",
949                                        ren1_src, ren1_dst, branch1,
950                                        ren1_dst, branch2);
951                                 conflict_rename_dir(ren1, branch1);
952                         } else if (sha_eq(src_other.sha1, null_sha1)) {
953                                 clean_merge = 0;
954                                 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
955                                        "and deleted in %s",
956                                        ren1_src, ren1_dst, branch1,
957                                        branch2);
958                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
959                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
960                                 const char *new_path;
961                                 clean_merge = 0;
962                                 try_merge = 1;
963                                 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
964                                        "%s added in %s",
965                                        ren1_src, ren1_dst, branch1,
966                                        ren1_dst, branch2);
967                                 new_path = unique_path(ren1_dst, branch2);
968                                 output(1, "Added as %s instead", new_path);
969                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
970                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
971                                 ren2 = item->util;
972                                 clean_merge = 0;
973                                 ren2->processed = 1;
974                                 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
975                                        "Renamed %s->%s in %s",
976                                        ren1_src, ren1_dst, branch1,
977                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
978                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
979                         } else
980                                 try_merge = 1;
981
982                         if (try_merge) {
983                                 struct diff_filespec *o, *a, *b;
984                                 struct merge_file_info mfi;
985                                 src_other.path = (char *)ren1_src;
986
987                                 o = ren1->pair->one;
988                                 if (a_renames == renames1) {
989                                         a = ren1->pair->two;
990                                         b = &src_other;
991                                 } else {
992                                         b = ren1->pair->two;
993                                         a = &src_other;
994                                 }
995                                 mfi = merge_file(o, a, b,
996                                                 a_branch, b_branch);
997
998                                 if (mfi.merge || !mfi.clean)
999                                         output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1000                                 if (mfi.merge)
1001                                         output(2, "Auto-merged %s", ren1_dst);
1002                                 if (!mfi.clean) {
1003                                         output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1004                                                ren1_dst);
1005                                         clean_merge = 0;
1006
1007                                         if (!index_only)
1008                                                 update_stages(ren1_dst,
1009                                                                 o, a, b, 1);
1010                                 }
1011                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1012                         }
1013                 }
1014         }
1015         path_list_clear(&a_by_dst, 0);
1016         path_list_clear(&b_by_dst, 0);
1017
1018         return clean_merge;
1019 }
1020
1021 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1022 {
1023         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1024 }
1025
1026 /* Per entry merge function */
1027 static int process_entry(const char *path, struct stage_data *entry,
1028                          const char *branch1,
1029                          const char *branch2)
1030 {
1031         /*
1032         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1033         print_index_entry("\tpath: ", entry);
1034         */
1035         int clean_merge = 1;
1036         unsigned o_mode = entry->stages[1].mode;
1037         unsigned a_mode = entry->stages[2].mode;
1038         unsigned b_mode = entry->stages[3].mode;
1039         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1040         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1041         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1042
1043         if (o_sha && (!a_sha || !b_sha)) {
1044                 /* Case A: Deleted in one */
1045                 if ((!a_sha && !b_sha) ||
1046                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1047                     (!a_sha && sha_eq(b_sha, o_sha))) {
1048                         /* Deleted in both or deleted in one and
1049                          * unchanged in the other */
1050                         if (a_sha)
1051                                 output(2, "Removed %s", path);
1052                         /* do not touch working file if it did not exist */
1053                         remove_file(1, path, !a_sha);
1054                 } else {
1055                         /* Deleted in one and changed in the other */
1056                         clean_merge = 0;
1057                         if (!a_sha) {
1058                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1059                                        "and modified in %s. Version %s of %s left in tree.",
1060                                        path, branch1,
1061                                        branch2, branch2, path);
1062                                 update_file(0, b_sha, b_mode, path);
1063                         } else {
1064                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1065                                        "and modified in %s. Version %s of %s left in tree.",
1066                                        path, branch2,
1067                                        branch1, branch1, path);
1068                                 update_file(0, a_sha, a_mode, path);
1069                         }
1070                 }
1071
1072         } else if ((!o_sha && a_sha && !b_sha) ||
1073                    (!o_sha && !a_sha && b_sha)) {
1074                 /* Case B: Added in one. */
1075                 const char *add_branch;
1076                 const char *other_branch;
1077                 unsigned mode;
1078                 const unsigned char *sha;
1079                 const char *conf;
1080
1081                 if (a_sha) {
1082                         add_branch = branch1;
1083                         other_branch = branch2;
1084                         mode = a_mode;
1085                         sha = a_sha;
1086                         conf = "file/directory";
1087                 } else {
1088                         add_branch = branch2;
1089                         other_branch = branch1;
1090                         mode = b_mode;
1091                         sha = b_sha;
1092                         conf = "directory/file";
1093                 }
1094                 if (path_list_has_path(&current_directory_set, path)) {
1095                         const char *new_path = unique_path(path, add_branch);
1096                         clean_merge = 0;
1097                         output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1098                                "Added %s as %s",
1099                                conf, path, other_branch, path, new_path);
1100                         remove_file(0, path, 0);
1101                         update_file(0, sha, mode, new_path);
1102                 } else {
1103                         output(2, "Added %s", path);
1104                         update_file(1, sha, mode, path);
1105                 }
1106         } else if (a_sha && b_sha) {
1107                 /* Case C: Added in both (check for same permissions) and */
1108                 /* case D: Modified in both, but differently. */
1109                 const char *reason = "content";
1110                 struct merge_file_info mfi;
1111                 struct diff_filespec o, a, b;
1112
1113                 if (!o_sha) {
1114                         reason = "add/add";
1115                         o_sha = (unsigned char *)null_sha1;
1116                 }
1117                 output(2, "Auto-merged %s", path);
1118                 o.path = a.path = b.path = (char *)path;
1119                 hashcpy(o.sha1, o_sha);
1120                 o.mode = o_mode;
1121                 hashcpy(a.sha1, a_sha);
1122                 a.mode = a_mode;
1123                 hashcpy(b.sha1, b_sha);
1124                 b.mode = b_mode;
1125
1126                 mfi = merge_file(&o, &a, &b,
1127                                  branch1, branch2);
1128
1129                 if (mfi.clean)
1130                         update_file(1, mfi.sha, mfi.mode, path);
1131                 else {
1132                         clean_merge = 0;
1133                         output(1, "CONFLICT (%s): Merge conflict in %s",
1134                                         reason, path);
1135
1136                         if (index_only)
1137                                 update_file(0, mfi.sha, mfi.mode, path);
1138                         else
1139                                 update_file_flags(mfi.sha, mfi.mode, path,
1140                                               0 /* update_cache */, 1 /* update_working_directory */);
1141                 }
1142         } else if (!o_sha && !a_sha && !b_sha) {
1143                 /*
1144                  * this entry was deleted altogether. a_mode == 0 means
1145                  * we had that path and want to actively remove it.
1146                  */
1147                 remove_file(1, path, !a_mode);
1148         } else
1149                 die("Fatal merge failure, shouldn't happen.");
1150
1151         return clean_merge;
1152 }
1153
1154 static int merge_trees(struct tree *head,
1155                        struct tree *merge,
1156                        struct tree *common,
1157                        const char *branch1,
1158                        const char *branch2,
1159                        struct tree **result)
1160 {
1161         int code, clean;
1162
1163         if (subtree_merge) {
1164                 merge = shift_tree_object(head, merge);
1165                 common = shift_tree_object(head, common);
1166         }
1167
1168         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1169                 output(0, "Already uptodate!");
1170                 *result = head;
1171                 return 1;
1172         }
1173
1174         code = git_merge_trees(index_only, common, head, merge);
1175
1176         if (code != 0)
1177                 die("merging of trees %s and %s failed",
1178                     sha1_to_hex(head->object.sha1),
1179                     sha1_to_hex(merge->object.sha1));
1180
1181         if (unmerged_index()) {
1182                 struct path_list *entries, *re_head, *re_merge;
1183                 int i;
1184                 path_list_clear(&current_file_set, 1);
1185                 path_list_clear(&current_directory_set, 1);
1186                 get_files_dirs(head);
1187                 get_files_dirs(merge);
1188
1189                 entries = get_unmerged();
1190                 re_head  = get_renames(head, common, head, merge, entries);
1191                 re_merge = get_renames(merge, common, head, merge, entries);
1192                 clean = process_renames(re_head, re_merge,
1193                                 branch1, branch2);
1194                 total_cnt += entries->nr;
1195                 for (i = 0; i < entries->nr; i++, merged_cnt++) {
1196                         const char *path = entries->items[i].path;
1197                         struct stage_data *e = entries->items[i].util;
1198                         if (!e->processed
1199                                 && !process_entry(path, e, branch1, branch2))
1200                                 clean = 0;
1201                         if (do_progress)
1202                                 display_progress();
1203                 }
1204
1205                 path_list_clear(re_merge, 0);
1206                 path_list_clear(re_head, 0);
1207                 path_list_clear(entries, 1);
1208
1209         }
1210         else
1211                 clean = 1;
1212
1213         if (index_only)
1214                 *result = git_write_tree();
1215
1216         return clean;
1217 }
1218
1219 static struct commit_list *reverse_commit_list(struct commit_list *list)
1220 {
1221         struct commit_list *next = NULL, *current, *backup;
1222         for (current = list; current; current = backup) {
1223                 backup = current->next;
1224                 current->next = next;
1225                 next = current;
1226         }
1227         return next;
1228 }
1229
1230 /*
1231  * Merge the commits h1 and h2, return the resulting virtual
1232  * commit object and a flag indicating the cleanness of the merge.
1233  */
1234 static int merge(struct commit *h1,
1235                  struct commit *h2,
1236                  const char *branch1,
1237                  const char *branch2,
1238                  struct commit_list *ca,
1239                  struct commit **result)
1240 {
1241         struct commit_list *iter;
1242         struct commit *merged_common_ancestors;
1243         struct tree *mrtree;
1244         int clean;
1245
1246         if (show(4)) {
1247                 output(4, "Merging:");
1248                 output_commit_title(h1);
1249                 output_commit_title(h2);
1250         }
1251
1252         if (!ca) {
1253                 ca = get_merge_bases(h1, h2, 1);
1254                 ca = reverse_commit_list(ca);
1255         }
1256
1257         if (show(5)) {
1258                 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1259                 for (iter = ca; iter; iter = iter->next)
1260                         output_commit_title(iter->item);
1261         }
1262
1263         merged_common_ancestors = pop_commit(&ca);
1264         if (merged_common_ancestors == NULL) {
1265                 /* if there is no common ancestor, make an empty tree */
1266                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1267
1268                 tree->object.parsed = 1;
1269                 tree->object.type = OBJ_TREE;
1270                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1271                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1272         }
1273
1274         for (iter = ca; iter; iter = iter->next) {
1275                 call_depth++;
1276                 /*
1277                  * When the merge fails, the result contains files
1278                  * with conflict markers. The cleanness flag is
1279                  * ignored, it was never actually used, as result of
1280                  * merge_trees has always overwritten it: the committed
1281                  * "conflicts" were already resolved.
1282                  */
1283                 discard_cache();
1284                 merge(merged_common_ancestors, iter->item,
1285                       "Temporary merge branch 1",
1286                       "Temporary merge branch 2",
1287                       NULL,
1288                       &merged_common_ancestors);
1289                 call_depth--;
1290
1291                 if (!merged_common_ancestors)
1292                         die("merge returned no commit");
1293         }
1294
1295         discard_cache();
1296         if (!call_depth) {
1297                 read_cache();
1298                 index_only = 0;
1299         } else
1300                 index_only = 1;
1301
1302         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1303                             branch1, branch2, &mrtree);
1304
1305         if (index_only) {
1306                 *result = make_virtual_commit(mrtree, "merged tree");
1307                 commit_list_insert(h1, &(*result)->parents);
1308                 commit_list_insert(h2, &(*result)->parents->next);
1309         }
1310         if (!call_depth && do_progress) {
1311                 /* Make sure we end at 100% */
1312                 if (!total_cnt)
1313                         total_cnt = 1;
1314                 merged_cnt = total_cnt;
1315                 progress_update = 1;
1316                 display_progress();
1317                 fputc('\n', stderr);
1318         }
1319         flush_output();
1320         return clean;
1321 }
1322
1323 static const char *better_branch_name(const char *branch)
1324 {
1325         static char githead_env[8 + 40 + 1];
1326         char *name;
1327
1328         if (strlen(branch) != 40)
1329                 return branch;
1330         sprintf(githead_env, "GITHEAD_%s", branch);
1331         name = getenv(githead_env);
1332         return name ? name : branch;
1333 }
1334
1335 static struct commit *get_ref(const char *ref)
1336 {
1337         unsigned char sha1[20];
1338         struct object *object;
1339
1340         if (get_sha1(ref, sha1))
1341                 die("Could not resolve ref '%s'", ref);
1342         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1343         if (object->type == OBJ_TREE)
1344                 return make_virtual_commit((struct tree*)object,
1345                         better_branch_name(ref));
1346         if (object->type != OBJ_COMMIT)
1347                 return NULL;
1348         if (parse_commit((struct commit *)object))
1349                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1350         return (struct commit *)object;
1351 }
1352
1353 static int merge_config(const char *var, const char *value)
1354 {
1355         if (!strcasecmp(var, "merge.verbosity")) {
1356                 verbosity = git_config_int(var, value);
1357                 return 0;
1358         }
1359         return git_default_config(var, value);
1360 }
1361
1362 int main(int argc, char *argv[])
1363 {
1364         static const char *bases[20];
1365         static unsigned bases_count = 0;
1366         int i, clean;
1367         const char *branch1, *branch2;
1368         struct commit *result, *h1, *h2;
1369         struct commit_list *ca = NULL;
1370         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1371         int index_fd;
1372
1373         if (argv[0]) {
1374                 int namelen = strlen(argv[0]);
1375                 if (8 < namelen &&
1376                     !strcmp(argv[0] + namelen - 8, "-subtree"))
1377                         subtree_merge = 1;
1378         }
1379
1380         git_config(merge_config);
1381         if (getenv("GIT_MERGE_VERBOSITY"))
1382                 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1383
1384         if (argc < 4)
1385                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1386
1387         for (i = 1; i < argc; ++i) {
1388                 if (!strcmp(argv[i], "--"))
1389                         break;
1390                 if (bases_count < sizeof(bases)/sizeof(*bases))
1391                         bases[bases_count++] = argv[i];
1392         }
1393         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1394                 die("Not handling anything other than two heads merge.");
1395         if (verbosity >= 5) {
1396                 buffer_output = 0;
1397                 do_progress = 0;
1398         }
1399         else
1400                 do_progress = isatty(1);
1401
1402         branch1 = argv[++i];
1403         branch2 = argv[++i];
1404
1405         h1 = get_ref(branch1);
1406         h2 = get_ref(branch2);
1407
1408         branch1 = better_branch_name(branch1);
1409         branch2 = better_branch_name(branch2);
1410
1411         if (do_progress)
1412                 setup_progress_signal();
1413         if (show(3))
1414                 printf("Merging %s with %s\n", branch1, branch2);
1415
1416         index_fd = hold_locked_index(lock, 1);
1417
1418         for (i = 0; i < bases_count; i++) {
1419                 struct commit *ancestor = get_ref(bases[i]);
1420                 ca = commit_list_insert(ancestor, &ca);
1421         }
1422         clean = merge(h1, h2, branch1, branch2, ca, &result);
1423
1424         if (active_cache_changed &&
1425             (write_cache(index_fd, active_cache, active_nr) ||
1426              close(index_fd) || commit_locked_index(lock)))
1427                         die ("unable to write %s", get_index_file());
1428
1429         return clean ? 0: 1;
1430 }