Merge branch 'maint-1.5.4' into maint
[git] / builtin-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 "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22
23 static int subtree_merge;
24
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27         unsigned char shifted[20];
28
29         /*
30          * NEEDSWORK: this limits the recursion depth to hardcoded
31          * value '2' to avoid excessive overhead.
32          */
33         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
34         if (!hashcmp(two->object.sha1, shifted))
35                 return two;
36         return lookup_tree(shifted);
37 }
38
39 /*
40  * A virtual commit has
41  * - (const char *)commit->util set to the name, and
42  * - *(int *)commit->object.sha1 set to the virtual id.
43  */
44
45 static unsigned commit_list_count(const struct commit_list *l)
46 {
47         unsigned c = 0;
48         for (; l; l = l->next )
49                 c++;
50         return c;
51 }
52
53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
54 {
55         struct commit *commit = xcalloc(1, sizeof(struct commit));
56         static unsigned virtual_id = 1;
57         commit->tree = tree;
58         commit->util = (void*)comment;
59         *(int*)commit->object.sha1 = virtual_id++;
60         /* avoid warnings */
61         commit->object.parsed = 1;
62         return commit;
63 }
64
65 /*
66  * Since we use get_tree_entry(), which does not put the read object into
67  * the object pool, we cannot rely on a == b.
68  */
69 static int sha_eq(const unsigned char *a, const unsigned char *b)
70 {
71         if (!a && !b)
72                 return 2;
73         return a && b && hashcmp(a, b) == 0;
74 }
75
76 /*
77  * Since we want to write the index eventually, we cannot reuse the index
78  * for these (temporary) data.
79  */
80 struct stage_data
81 {
82         struct
83         {
84                 unsigned mode;
85                 unsigned char sha[20];
86         } stages[4];
87         unsigned processed:1;
88 };
89
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
92
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int rename_limit = -1;
96 static int buffer_output = 1;
97 static struct strbuf obuf = STRBUF_INIT;
98
99 static int show(int v)
100 {
101         return (!call_depth && verbosity >= v) || verbosity >= 5;
102 }
103
104 static void flush_output(void)
105 {
106         if (obuf.len) {
107                 fputs(obuf.buf, stdout);
108                 strbuf_reset(&obuf);
109         }
110 }
111
112 static void output(int v, const char *fmt, ...)
113 {
114         int len;
115         va_list ap;
116
117         if (!show(v))
118                 return;
119
120         strbuf_grow(&obuf, call_depth * 2 + 2);
121         memset(obuf.buf + obuf.len, ' ', call_depth * 2);
122         strbuf_setlen(&obuf, obuf.len + call_depth * 2);
123
124         va_start(ap, fmt);
125         len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
126         va_end(ap);
127
128         if (len < 0)
129                 len = 0;
130         if (len >= strbuf_avail(&obuf)) {
131                 strbuf_grow(&obuf, len + 2);
132                 va_start(ap, fmt);
133                 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
134                 va_end(ap);
135                 if (len >= strbuf_avail(&obuf)) {
136                         die("this should not happen, your snprintf is broken");
137                 }
138         }
139         strbuf_setlen(&obuf, obuf.len + len);
140         strbuf_add(&obuf, "\n", 1);
141         if (!buffer_output)
142                 flush_output();
143 }
144
145 static void output_commit_title(struct commit *commit)
146 {
147         int i;
148         flush_output();
149         for (i = call_depth; i--;)
150                 fputs("  ", stdout);
151         if (commit->util)
152                 printf("virtual %s\n", (char *)commit->util);
153         else {
154                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
155                 if (parse_commit(commit) != 0)
156                         printf("(bad commit)\n");
157                 else {
158                         const char *s;
159                         int len;
160                         for (s = commit->buffer; *s; s++)
161                                 if (*s == '\n' && s[1] == '\n') {
162                                         s += 2;
163                                         break;
164                                 }
165                         for (len = 0; s[len] && '\n' != s[len]; len++)
166                                 ; /* do nothing */
167                         printf("%.*s\n", len, s);
168                 }
169         }
170 }
171
172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
173                 const char *path, int stage, int refresh, int options)
174 {
175         struct cache_entry *ce;
176         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
177         if (!ce)
178                 return error("addinfo_cache failed for path '%s'", path);
179         return add_cache_entry(ce, options);
180 }
181
182 /*
183  * This is a global variable which is used in a number of places but
184  * only written to in the 'merge' function.
185  *
186  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
187  *                       don't update the working directory.
188  *               0    => Leave unmerged entries in the cache and update
189  *                       the working directory.
190  */
191 static int index_only = 0;
192
193 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
194 {
195         parse_tree(tree);
196         init_tree_desc(desc, tree->buffer, tree->size);
197 }
198
199 static int git_merge_trees(int index_only,
200                            struct tree *common,
201                            struct tree *head,
202                            struct tree *merge)
203 {
204         int rc;
205         struct tree_desc t[3];
206         struct unpack_trees_options opts;
207
208         memset(&opts, 0, sizeof(opts));
209         if (index_only)
210                 opts.index_only = 1;
211         else
212                 opts.update = 1;
213         opts.merge = 1;
214         opts.head_idx = 2;
215         opts.fn = threeway_merge;
216         opts.src_index = &the_index;
217         opts.dst_index = &the_index;
218
219         init_tree_desc_from_tree(t+0, common);
220         init_tree_desc_from_tree(t+1, head);
221         init_tree_desc_from_tree(t+2, merge);
222
223         rc = unpack_trees(3, t, &opts);
224         cache_tree_free(&active_cache_tree);
225         return rc;
226 }
227
228 struct tree *write_tree_from_memory(void)
229 {
230         struct tree *result = NULL;
231
232         if (unmerged_cache()) {
233                 int i;
234                 output(0, "There are unmerged index entries:");
235                 for (i = 0; i < active_nr; i++) {
236                         struct cache_entry *ce = active_cache[i];
237                         if (ce_stage(ce))
238                                 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
239                 }
240                 return NULL;
241         }
242
243         if (!active_cache_tree)
244                 active_cache_tree = cache_tree();
245
246         if (!cache_tree_fully_valid(active_cache_tree) &&
247             cache_tree_update(active_cache_tree,
248                               active_cache, active_nr, 0, 0) < 0)
249                 die("error building trees");
250
251         result = lookup_tree(active_cache_tree->sha1);
252
253         return result;
254 }
255
256 static int save_files_dirs(const unsigned char *sha1,
257                 const char *base, int baselen, const char *path,
258                 unsigned int mode, int stage)
259 {
260         int len = strlen(path);
261         char *newpath = xmalloc(baselen + len + 1);
262         memcpy(newpath, base, baselen);
263         memcpy(newpath + baselen, path, len);
264         newpath[baselen + len] = '\0';
265
266         if (S_ISDIR(mode))
267                 path_list_insert(newpath, &current_directory_set);
268         else
269                 path_list_insert(newpath, &current_file_set);
270         free(newpath);
271
272         return READ_TREE_RECURSIVE;
273 }
274
275 static int get_files_dirs(struct tree *tree)
276 {
277         int n;
278         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
279                 return 0;
280         n = current_file_set.nr + current_directory_set.nr;
281         return n;
282 }
283
284 /*
285  * Returns an index_entry instance which doesn't have to correspond to
286  * a real cache entry in Git's index.
287  */
288 static struct stage_data *insert_stage_data(const char *path,
289                 struct tree *o, struct tree *a, struct tree *b,
290                 struct path_list *entries)
291 {
292         struct path_list_item *item;
293         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
294         get_tree_entry(o->object.sha1, path,
295                         e->stages[1].sha, &e->stages[1].mode);
296         get_tree_entry(a->object.sha1, path,
297                         e->stages[2].sha, &e->stages[2].mode);
298         get_tree_entry(b->object.sha1, path,
299                         e->stages[3].sha, &e->stages[3].mode);
300         item = path_list_insert(path, entries);
301         item->util = e;
302         return e;
303 }
304
305 /*
306  * Create a dictionary mapping file names to stage_data objects. The
307  * dictionary contains one entry for every path with a non-zero stage entry.
308  */
309 static struct path_list *get_unmerged(void)
310 {
311         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
312         int i;
313
314         unmerged->strdup_paths = 1;
315
316         for (i = 0; i < active_nr; i++) {
317                 struct path_list_item *item;
318                 struct stage_data *e;
319                 struct cache_entry *ce = active_cache[i];
320                 if (!ce_stage(ce))
321                         continue;
322
323                 item = path_list_lookup(ce->name, unmerged);
324                 if (!item) {
325                         item = path_list_insert(ce->name, unmerged);
326                         item->util = xcalloc(1, sizeof(struct stage_data));
327                 }
328                 e = item->util;
329                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
330                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
331         }
332
333         return unmerged;
334 }
335
336 struct rename
337 {
338         struct diff_filepair *pair;
339         struct stage_data *src_entry;
340         struct stage_data *dst_entry;
341         unsigned processed:1;
342 };
343
344 /*
345  * Get information of all renames which occurred between 'o_tree' and
346  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
347  * 'b_tree') to be able to associate the correct cache entries with
348  * the rename information. 'tree' is always equal to either a_tree or b_tree.
349  */
350 static struct path_list *get_renames(struct tree *tree,
351                                         struct tree *o_tree,
352                                         struct tree *a_tree,
353                                         struct tree *b_tree,
354                                         struct path_list *entries)
355 {
356         int i;
357         struct path_list *renames;
358         struct diff_options opts;
359
360         renames = xcalloc(1, sizeof(struct path_list));
361         diff_setup(&opts);
362         DIFF_OPT_SET(&opts, RECURSIVE);
363         opts.detect_rename = DIFF_DETECT_RENAME;
364         opts.rename_limit = rename_limit;
365         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
366         if (diff_setup_done(&opts) < 0)
367                 die("diff setup failed");
368         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
369         diffcore_std(&opts);
370         for (i = 0; i < diff_queued_diff.nr; ++i) {
371                 struct path_list_item *item;
372                 struct rename *re;
373                 struct diff_filepair *pair = diff_queued_diff.queue[i];
374                 if (pair->status != 'R') {
375                         diff_free_filepair(pair);
376                         continue;
377                 }
378                 re = xmalloc(sizeof(*re));
379                 re->processed = 0;
380                 re->pair = pair;
381                 item = path_list_lookup(re->pair->one->path, entries);
382                 if (!item)
383                         re->src_entry = insert_stage_data(re->pair->one->path,
384                                         o_tree, a_tree, b_tree, entries);
385                 else
386                         re->src_entry = item->util;
387
388                 item = path_list_lookup(re->pair->two->path, entries);
389                 if (!item)
390                         re->dst_entry = insert_stage_data(re->pair->two->path,
391                                         o_tree, a_tree, b_tree, entries);
392                 else
393                         re->dst_entry = item->util;
394                 item = path_list_insert(pair->one->path, renames);
395                 item->util = re;
396         }
397         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
398         diff_queued_diff.nr = 0;
399         diff_flush(&opts);
400         return renames;
401 }
402
403 static int update_stages(const char *path, struct diff_filespec *o,
404                          struct diff_filespec *a, struct diff_filespec *b,
405                          int clear)
406 {
407         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
408         if (clear)
409                 if (remove_file_from_cache(path))
410                         return -1;
411         if (o)
412                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
413                         return -1;
414         if (a)
415                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
416                         return -1;
417         if (b)
418                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
419                         return -1;
420         return 0;
421 }
422
423 static int remove_path(const char *name)
424 {
425         int ret;
426         char *slash, *dirs;
427
428         ret = unlink(name);
429         if (ret)
430                 return ret;
431         dirs = xstrdup(name);
432         while ((slash = strrchr(name, '/'))) {
433                 *slash = '\0';
434                 if (rmdir(name) != 0)
435                         break;
436         }
437         free(dirs);
438         return ret;
439 }
440
441 static int remove_file(int clean, const char *path, int no_wd)
442 {
443         int update_cache = index_only || clean;
444         int update_working_directory = !index_only && !no_wd;
445
446         if (update_cache) {
447                 if (remove_file_from_cache(path))
448                         return -1;
449         }
450         if (update_working_directory) {
451                 unlink(path);
452                 if (errno != ENOENT || errno != EISDIR)
453                         return -1;
454                 remove_path(path);
455         }
456         return 0;
457 }
458
459 static char *unique_path(const char *path, const char *branch)
460 {
461         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
462         int suffix = 0;
463         struct stat st;
464         char *p = newpath + strlen(path);
465         strcpy(newpath, path);
466         *(p++) = '~';
467         strcpy(p, branch);
468         for (; *p; ++p)
469                 if ('/' == *p)
470                         *p = '_';
471         while (path_list_has_path(&current_file_set, newpath) ||
472                path_list_has_path(&current_directory_set, newpath) ||
473                lstat(newpath, &st) == 0)
474                 sprintf(p, "_%d", suffix++);
475
476         path_list_insert(newpath, &current_file_set);
477         return newpath;
478 }
479
480 static int mkdir_p(const char *path, unsigned long mode)
481 {
482         /* path points to cache entries, so xstrdup before messing with it */
483         char *buf = xstrdup(path);
484         int result = safe_create_leading_directories(buf);
485         free(buf);
486         return result;
487 }
488
489 static void flush_buffer(int fd, const char *buf, unsigned long size)
490 {
491         while (size > 0) {
492                 long ret = write_in_full(fd, buf, size);
493                 if (ret < 0) {
494                         /* Ignore epipe */
495                         if (errno == EPIPE)
496                                 break;
497                         die("merge-recursive: %s", strerror(errno));
498                 } else if (!ret) {
499                         die("merge-recursive: disk full?");
500                 }
501                 size -= ret;
502                 buf += ret;
503         }
504 }
505
506 static int make_room_for_path(const char *path)
507 {
508         int status;
509         const char *msg = "failed to create path '%s'%s";
510
511         status = mkdir_p(path, 0777);
512         if (status) {
513                 if (status == -3) {
514                         /* something else exists */
515                         error(msg, path, ": perhaps a D/F conflict?");
516                         return -1;
517                 }
518                 die(msg, path, "");
519         }
520
521         /* Successful unlink is good.. */
522         if (!unlink(path))
523                 return 0;
524         /* .. and so is no existing file */
525         if (errno == ENOENT)
526                 return 0;
527         /* .. but not some other error (who really cares what?) */
528         return error(msg, path, ": perhaps a D/F conflict?");
529 }
530
531 static void update_file_flags(const unsigned char *sha,
532                               unsigned mode,
533                               const char *path,
534                               int update_cache,
535                               int update_wd)
536 {
537         if (index_only)
538                 update_wd = 0;
539
540         if (update_wd) {
541                 enum object_type type;
542                 void *buf;
543                 unsigned long size;
544
545                 if (S_ISGITLINK(mode))
546                         die("cannot read object %s '%s': It is a submodule!",
547                             sha1_to_hex(sha), path);
548
549                 buf = read_sha1_file(sha, &type, &size);
550                 if (!buf)
551                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
552                 if (type != OBJ_BLOB)
553                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
554
555                 if (make_room_for_path(path) < 0) {
556                         update_wd = 0;
557                         goto update_index;
558                 }
559                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
560                         int fd;
561                         if (mode & 0100)
562                                 mode = 0777;
563                         else
564                                 mode = 0666;
565                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
566                         if (fd < 0)
567                                 die("failed to open %s: %s", path, strerror(errno));
568                         flush_buffer(fd, buf, size);
569                         close(fd);
570                 } else if (S_ISLNK(mode)) {
571                         char *lnk = xmemdupz(buf, size);
572                         mkdir_p(path, 0777);
573                         unlink(path);
574                         symlink(lnk, path);
575                         free(lnk);
576                 } else
577                         die("do not know what to do with %06o %s '%s'",
578                             mode, sha1_to_hex(sha), path);
579         }
580  update_index:
581         if (update_cache)
582                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
583 }
584
585 static void update_file(int clean,
586                         const unsigned char *sha,
587                         unsigned mode,
588                         const char *path)
589 {
590         update_file_flags(sha, mode, path, index_only || clean, !index_only);
591 }
592
593 /* Low level file merging, update and removal */
594
595 struct merge_file_info
596 {
597         unsigned char sha[20];
598         unsigned mode;
599         unsigned clean:1,
600                  merge:1;
601 };
602
603 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
604 {
605         unsigned long size;
606         enum object_type type;
607
608         if (!hashcmp(sha1, null_sha1)) {
609                 mm->ptr = xstrdup("");
610                 mm->size = 0;
611                 return;
612         }
613
614         mm->ptr = read_sha1_file(sha1, &type, &size);
615         if (!mm->ptr || type != OBJ_BLOB)
616                 die("unable to read blob object %s", sha1_to_hex(sha1));
617         mm->size = size;
618 }
619
620 static int merge_3way(mmbuffer_t *result_buf,
621                       struct diff_filespec *o,
622                       struct diff_filespec *a,
623                       struct diff_filespec *b,
624                       const char *branch1,
625                       const char *branch2)
626 {
627         mmfile_t orig, src1, src2;
628         char *name1, *name2;
629         int merge_status;
630
631         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
632         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
633
634         fill_mm(o->sha1, &orig);
635         fill_mm(a->sha1, &src1);
636         fill_mm(b->sha1, &src2);
637
638         merge_status = ll_merge(result_buf, a->path, &orig,
639                                 &src1, name1, &src2, name2,
640                                 index_only);
641
642         free(name1);
643         free(name2);
644         free(orig.ptr);
645         free(src1.ptr);
646         free(src2.ptr);
647         return merge_status;
648 }
649
650 static struct merge_file_info merge_file(struct diff_filespec *o,
651                 struct diff_filespec *a, struct diff_filespec *b,
652                 const char *branch1, const char *branch2)
653 {
654         struct merge_file_info result;
655         result.merge = 0;
656         result.clean = 1;
657
658         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
659                 result.clean = 0;
660                 if (S_ISREG(a->mode)) {
661                         result.mode = a->mode;
662                         hashcpy(result.sha, a->sha1);
663                 } else {
664                         result.mode = b->mode;
665                         hashcpy(result.sha, b->sha1);
666                 }
667         } else {
668                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
669                         result.merge = 1;
670
671                 /*
672                  * Merge modes
673                  */
674                 if (a->mode == b->mode || a->mode == o->mode)
675                         result.mode = b->mode;
676                 else {
677                         result.mode = a->mode;
678                         if (b->mode != o->mode) {
679                                 result.clean = 0;
680                                 result.merge = 1;
681                         }
682                 }
683
684                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, o->sha1))
685                         hashcpy(result.sha, b->sha1);
686                 else if (sha_eq(b->sha1, o->sha1))
687                         hashcpy(result.sha, a->sha1);
688                 else if (S_ISREG(a->mode)) {
689                         mmbuffer_t result_buf;
690                         int merge_status;
691
692                         merge_status = merge_3way(&result_buf, o, a, b,
693                                                   branch1, branch2);
694
695                         if ((merge_status < 0) || !result_buf.ptr)
696                                 die("Failed to execute internal merge");
697
698                         if (write_sha1_file(result_buf.ptr, result_buf.size,
699                                             blob_type, result.sha))
700                                 die("Unable to add %s to database",
701                                     a->path);
702
703                         free(result_buf.ptr);
704                         result.clean = (merge_status == 0);
705                 } else if (S_ISGITLINK(a->mode)) {
706                         result.clean = 0;
707                         hashcpy(result.sha, a->sha1);
708                 } else if (S_ISLNK(a->mode)) {
709                         hashcpy(result.sha, a->sha1);
710
711                         if (!sha_eq(a->sha1, b->sha1))
712                                 result.clean = 0;
713                 } else {
714                         die("unsupported object type in the tree");
715                 }
716         }
717
718         return result;
719 }
720
721 static void conflict_rename_rename(struct rename *ren1,
722                                    const char *branch1,
723                                    struct rename *ren2,
724                                    const char *branch2)
725 {
726         char *del[2];
727         int delp = 0;
728         const char *ren1_dst = ren1->pair->two->path;
729         const char *ren2_dst = ren2->pair->two->path;
730         const char *dst_name1 = ren1_dst;
731         const char *dst_name2 = ren2_dst;
732         if (path_list_has_path(&current_directory_set, ren1_dst)) {
733                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
734                 output(1, "%s is a directory in %s added as %s instead",
735                        ren1_dst, branch2, dst_name1);
736                 remove_file(0, ren1_dst, 0);
737         }
738         if (path_list_has_path(&current_directory_set, ren2_dst)) {
739                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
740                 output(1, "%s is a directory in %s added as %s instead",
741                        ren2_dst, branch1, dst_name2);
742                 remove_file(0, ren2_dst, 0);
743         }
744         if (index_only) {
745                 remove_file_from_cache(dst_name1);
746                 remove_file_from_cache(dst_name2);
747                 /*
748                  * Uncomment to leave the conflicting names in the resulting tree
749                  *
750                  * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
751                  * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
752                  */
753         } else {
754                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
755                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
756         }
757         while (delp--)
758                 free(del[delp]);
759 }
760
761 static void conflict_rename_dir(struct rename *ren1,
762                                 const char *branch1)
763 {
764         char *new_path = unique_path(ren1->pair->two->path, branch1);
765         output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
766         remove_file(0, ren1->pair->two->path, 0);
767         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
768         free(new_path);
769 }
770
771 static void conflict_rename_rename_2(struct rename *ren1,
772                                      const char *branch1,
773                                      struct rename *ren2,
774                                      const char *branch2)
775 {
776         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
777         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
778         output(1, "Renamed %s to %s and %s to %s instead",
779                ren1->pair->one->path, new_path1,
780                ren2->pair->one->path, new_path2);
781         remove_file(0, ren1->pair->two->path, 0);
782         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
783         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
784         free(new_path2);
785         free(new_path1);
786 }
787
788 static int process_renames(struct path_list *a_renames,
789                            struct path_list *b_renames,
790                            const char *a_branch,
791                            const char *b_branch)
792 {
793         int clean_merge = 1, i, j;
794         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
795         const struct rename *sre;
796
797         for (i = 0; i < a_renames->nr; i++) {
798                 sre = a_renames->items[i].util;
799                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
800                         = sre->dst_entry;
801         }
802         for (i = 0; i < b_renames->nr; i++) {
803                 sre = b_renames->items[i].util;
804                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
805                         = sre->dst_entry;
806         }
807
808         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
809                 int compare;
810                 char *src;
811                 struct path_list *renames1, *renames2, *renames2Dst;
812                 struct rename *ren1 = NULL, *ren2 = NULL;
813                 const char *branch1, *branch2;
814                 const char *ren1_src, *ren1_dst;
815
816                 if (i >= a_renames->nr) {
817                         compare = 1;
818                         ren2 = b_renames->items[j++].util;
819                 } else if (j >= b_renames->nr) {
820                         compare = -1;
821                         ren1 = a_renames->items[i++].util;
822                 } else {
823                         compare = strcmp(a_renames->items[i].path,
824                                         b_renames->items[j].path);
825                         if (compare <= 0)
826                                 ren1 = a_renames->items[i++].util;
827                         if (compare >= 0)
828                                 ren2 = b_renames->items[j++].util;
829                 }
830
831                 /* TODO: refactor, so that 1/2 are not needed */
832                 if (ren1) {
833                         renames1 = a_renames;
834                         renames2 = b_renames;
835                         renames2Dst = &b_by_dst;
836                         branch1 = a_branch;
837                         branch2 = b_branch;
838                 } else {
839                         struct rename *tmp;
840                         renames1 = b_renames;
841                         renames2 = a_renames;
842                         renames2Dst = &a_by_dst;
843                         branch1 = b_branch;
844                         branch2 = a_branch;
845                         tmp = ren2;
846                         ren2 = ren1;
847                         ren1 = tmp;
848                 }
849                 src = ren1->pair->one->path;
850
851                 ren1->dst_entry->processed = 1;
852                 ren1->src_entry->processed = 1;
853
854                 if (ren1->processed)
855                         continue;
856                 ren1->processed = 1;
857
858                 ren1_src = ren1->pair->one->path;
859                 ren1_dst = ren1->pair->two->path;
860
861                 if (ren2) {
862                         const char *ren2_src = ren2->pair->one->path;
863                         const char *ren2_dst = ren2->pair->two->path;
864                         /* Renamed in 1 and renamed in 2 */
865                         if (strcmp(ren1_src, ren2_src) != 0)
866                                 die("ren1.src != ren2.src");
867                         ren2->dst_entry->processed = 1;
868                         ren2->processed = 1;
869                         if (strcmp(ren1_dst, ren2_dst) != 0) {
870                                 clean_merge = 0;
871                                 output(1, "CONFLICT (rename/rename): "
872                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
873                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
874                                        src, ren1_dst, branch1,
875                                        src, ren2_dst, branch2,
876                                        index_only ? " (left unresolved)": "");
877                                 if (index_only) {
878                                         remove_file_from_cache(src);
879                                         update_file(0, ren1->pair->one->sha1,
880                                                     ren1->pair->one->mode, src);
881                                 }
882                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
883                         } else {
884                                 struct merge_file_info mfi;
885                                 remove_file(1, ren1_src, 1);
886                                 mfi = merge_file(ren1->pair->one,
887                                                  ren1->pair->two,
888                                                  ren2->pair->two,
889                                                  branch1,
890                                                  branch2);
891                                 if (mfi.merge || !mfi.clean)
892                                         output(1, "Renamed %s->%s", src, ren1_dst);
893
894                                 if (mfi.merge)
895                                         output(2, "Auto-merged %s", ren1_dst);
896
897                                 if (!mfi.clean) {
898                                         output(1, "CONFLICT (content): merge conflict in %s",
899                                                ren1_dst);
900                                         clean_merge = 0;
901
902                                         if (!index_only)
903                                                 update_stages(ren1_dst,
904                                                               ren1->pair->one,
905                                                               ren1->pair->two,
906                                                               ren2->pair->two,
907                                                               1 /* clear */);
908                                 }
909                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
910                         }
911                 } else {
912                         /* Renamed in 1, maybe changed in 2 */
913                         struct path_list_item *item;
914                         /* we only use sha1 and mode of these */
915                         struct diff_filespec src_other, dst_other;
916                         int try_merge, stage = a_renames == renames1 ? 3: 2;
917
918                         remove_file(1, ren1_src, index_only || stage == 3);
919
920                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
921                         src_other.mode = ren1->src_entry->stages[stage].mode;
922                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
923                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
924
925                         try_merge = 0;
926
927                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
928                                 clean_merge = 0;
929                                 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
930                                        " directory %s added in %s",
931                                        ren1_src, ren1_dst, branch1,
932                                        ren1_dst, branch2);
933                                 conflict_rename_dir(ren1, branch1);
934                         } else if (sha_eq(src_other.sha1, null_sha1)) {
935                                 clean_merge = 0;
936                                 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
937                                        "and deleted in %s",
938                                        ren1_src, ren1_dst, branch1,
939                                        branch2);
940                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
941                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
942                                 const char *new_path;
943                                 clean_merge = 0;
944                                 try_merge = 1;
945                                 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
946                                        "%s added in %s",
947                                        ren1_src, ren1_dst, branch1,
948                                        ren1_dst, branch2);
949                                 new_path = unique_path(ren1_dst, branch2);
950                                 output(1, "Added as %s instead", new_path);
951                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
952                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
953                                 ren2 = item->util;
954                                 clean_merge = 0;
955                                 ren2->processed = 1;
956                                 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
957                                        "Renamed %s->%s in %s",
958                                        ren1_src, ren1_dst, branch1,
959                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
960                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
961                         } else
962                                 try_merge = 1;
963
964                         if (try_merge) {
965                                 struct diff_filespec *o, *a, *b;
966                                 struct merge_file_info mfi;
967                                 src_other.path = (char *)ren1_src;
968
969                                 o = ren1->pair->one;
970                                 if (a_renames == renames1) {
971                                         a = ren1->pair->two;
972                                         b = &src_other;
973                                 } else {
974                                         b = ren1->pair->two;
975                                         a = &src_other;
976                                 }
977                                 mfi = merge_file(o, a, b,
978                                                 a_branch, b_branch);
979
980                                 if (mfi.clean &&
981                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
982                                     mfi.mode == ren1->pair->two->mode)
983                                         /*
984                                          * This messaged is part of
985                                          * t6022 test. If you change
986                                          * it update the test too.
987                                          */
988                                         output(3, "Skipped %s (merged same as existing)", ren1_dst);
989                                 else {
990                                         if (mfi.merge || !mfi.clean)
991                                                 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
992                                         if (mfi.merge)
993                                                 output(2, "Auto-merged %s", ren1_dst);
994                                         if (!mfi.clean) {
995                                                 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
996                                                        ren1_dst);
997                                                 clean_merge = 0;
998
999                                                 if (!index_only)
1000                                                         update_stages(ren1_dst,
1001                                                                       o, a, b, 1);
1002                                         }
1003                                         update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1004                                 }
1005                         }
1006                 }
1007         }
1008         path_list_clear(&a_by_dst, 0);
1009         path_list_clear(&b_by_dst, 0);
1010
1011         return clean_merge;
1012 }
1013
1014 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1015 {
1016         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1017 }
1018
1019 /* Per entry merge function */
1020 static int process_entry(const char *path, struct stage_data *entry,
1021                          const char *branch1,
1022                          const char *branch2)
1023 {
1024         /*
1025         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1026         print_index_entry("\tpath: ", entry);
1027         */
1028         int clean_merge = 1;
1029         unsigned o_mode = entry->stages[1].mode;
1030         unsigned a_mode = entry->stages[2].mode;
1031         unsigned b_mode = entry->stages[3].mode;
1032         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1033         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1034         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1035
1036         if (o_sha && (!a_sha || !b_sha)) {
1037                 /* Case A: Deleted in one */
1038                 if ((!a_sha && !b_sha) ||
1039                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1040                     (!a_sha && sha_eq(b_sha, o_sha))) {
1041                         /* Deleted in both or deleted in one and
1042                          * unchanged in the other */
1043                         if (a_sha)
1044                                 output(2, "Removed %s", path);
1045                         /* do not touch working file if it did not exist */
1046                         remove_file(1, path, !a_sha);
1047                 } else {
1048                         /* Deleted in one and changed in the other */
1049                         clean_merge = 0;
1050                         if (!a_sha) {
1051                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1052                                        "and modified in %s. Version %s of %s left in tree.",
1053                                        path, branch1,
1054                                        branch2, branch2, path);
1055                                 update_file(0, b_sha, b_mode, path);
1056                         } else {
1057                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1058                                        "and modified in %s. Version %s of %s left in tree.",
1059                                        path, branch2,
1060                                        branch1, branch1, path);
1061                                 update_file(0, a_sha, a_mode, path);
1062                         }
1063                 }
1064
1065         } else if ((!o_sha && a_sha && !b_sha) ||
1066                    (!o_sha && !a_sha && b_sha)) {
1067                 /* Case B: Added in one. */
1068                 const char *add_branch;
1069                 const char *other_branch;
1070                 unsigned mode;
1071                 const unsigned char *sha;
1072                 const char *conf;
1073
1074                 if (a_sha) {
1075                         add_branch = branch1;
1076                         other_branch = branch2;
1077                         mode = a_mode;
1078                         sha = a_sha;
1079                         conf = "file/directory";
1080                 } else {
1081                         add_branch = branch2;
1082                         other_branch = branch1;
1083                         mode = b_mode;
1084                         sha = b_sha;
1085                         conf = "directory/file";
1086                 }
1087                 if (path_list_has_path(&current_directory_set, path)) {
1088                         const char *new_path = unique_path(path, add_branch);
1089                         clean_merge = 0;
1090                         output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1091                                "Added %s as %s",
1092                                conf, path, other_branch, path, new_path);
1093                         remove_file(0, path, 0);
1094                         update_file(0, sha, mode, new_path);
1095                 } else {
1096                         output(2, "Added %s", path);
1097                         update_file(1, sha, mode, path);
1098                 }
1099         } else if (a_sha && b_sha) {
1100                 /* Case C: Added in both (check for same permissions) and */
1101                 /* case D: Modified in both, but differently. */
1102                 const char *reason = "content";
1103                 struct merge_file_info mfi;
1104                 struct diff_filespec o, a, b;
1105
1106                 if (!o_sha) {
1107                         reason = "add/add";
1108                         o_sha = (unsigned char *)null_sha1;
1109                 }
1110                 output(2, "Auto-merged %s", path);
1111                 o.path = a.path = b.path = (char *)path;
1112                 hashcpy(o.sha1, o_sha);
1113                 o.mode = o_mode;
1114                 hashcpy(a.sha1, a_sha);
1115                 a.mode = a_mode;
1116                 hashcpy(b.sha1, b_sha);
1117                 b.mode = b_mode;
1118
1119                 mfi = merge_file(&o, &a, &b,
1120                                  branch1, branch2);
1121
1122                 clean_merge = mfi.clean;
1123                 if (mfi.clean)
1124                         update_file(1, mfi.sha, mfi.mode, path);
1125                 else if (S_ISGITLINK(mfi.mode))
1126                         output(1, "CONFLICT (submodule): Merge conflict in %s "
1127                                "- needs %s", path, sha1_to_hex(b.sha1));
1128                 else {
1129                         output(1, "CONFLICT (%s): Merge conflict in %s",
1130                                         reason, path);
1131
1132                         if (index_only)
1133                                 update_file(0, mfi.sha, mfi.mode, path);
1134                         else
1135                                 update_file_flags(mfi.sha, mfi.mode, path,
1136                                               0 /* update_cache */, 1 /* update_working_directory */);
1137                 }
1138         } else if (!o_sha && !a_sha && !b_sha) {
1139                 /*
1140                  * this entry was deleted altogether. a_mode == 0 means
1141                  * we had that path and want to actively remove it.
1142                  */
1143                 remove_file(1, path, !a_mode);
1144         } else
1145                 die("Fatal merge failure, shouldn't happen.");
1146
1147         return clean_merge;
1148 }
1149
1150 int merge_trees(struct tree *head,
1151                 struct tree *merge,
1152                 struct tree *common,
1153                 const char *branch1,
1154                 const char *branch2,
1155                 struct tree **result)
1156 {
1157         int code, clean;
1158
1159         if (subtree_merge) {
1160                 merge = shift_tree_object(head, merge);
1161                 common = shift_tree_object(head, common);
1162         }
1163
1164         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1165                 output(0, "Already uptodate!");
1166                 *result = head;
1167                 return 1;
1168         }
1169
1170         code = git_merge_trees(index_only, common, head, merge);
1171
1172         if (code != 0)
1173                 die("merging of trees %s and %s failed",
1174                     sha1_to_hex(head->object.sha1),
1175                     sha1_to_hex(merge->object.sha1));
1176
1177         if (unmerged_cache()) {
1178                 struct path_list *entries, *re_head, *re_merge;
1179                 int i;
1180                 path_list_clear(&current_file_set, 1);
1181                 path_list_clear(&current_directory_set, 1);
1182                 get_files_dirs(head);
1183                 get_files_dirs(merge);
1184
1185                 entries = get_unmerged();
1186                 re_head  = get_renames(head, common, head, merge, entries);
1187                 re_merge = get_renames(merge, common, head, merge, entries);
1188                 clean = process_renames(re_head, re_merge,
1189                                 branch1, branch2);
1190                 for (i = 0; i < entries->nr; i++) {
1191                         const char *path = entries->items[i].path;
1192                         struct stage_data *e = entries->items[i].util;
1193                         if (!e->processed
1194                                 && !process_entry(path, e, branch1, branch2))
1195                                 clean = 0;
1196                 }
1197
1198                 path_list_clear(re_merge, 0);
1199                 path_list_clear(re_head, 0);
1200                 path_list_clear(entries, 1);
1201
1202         }
1203         else
1204                 clean = 1;
1205
1206         if (index_only)
1207                 *result = write_tree_from_memory();
1208
1209         return clean;
1210 }
1211
1212 static struct commit_list *reverse_commit_list(struct commit_list *list)
1213 {
1214         struct commit_list *next = NULL, *current, *backup;
1215         for (current = list; current; current = backup) {
1216                 backup = current->next;
1217                 current->next = next;
1218                 next = current;
1219         }
1220         return next;
1221 }
1222
1223 /*
1224  * Merge the commits h1 and h2, return the resulting virtual
1225  * commit object and a flag indicating the cleanness of the merge.
1226  */
1227 int merge_recursive(struct commit *h1,
1228                     struct commit *h2,
1229                     const char *branch1,
1230                     const char *branch2,
1231                     struct commit_list *ca,
1232                     struct commit **result)
1233 {
1234         struct commit_list *iter;
1235         struct commit *merged_common_ancestors;
1236         struct tree *mrtree = mrtree;
1237         int clean;
1238
1239         if (show(4)) {
1240                 output(4, "Merging:");
1241                 output_commit_title(h1);
1242                 output_commit_title(h2);
1243         }
1244
1245         if (!ca) {
1246                 ca = get_merge_bases(h1, h2, 1);
1247                 ca = reverse_commit_list(ca);
1248         }
1249
1250         if (show(5)) {
1251                 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1252                 for (iter = ca; iter; iter = iter->next)
1253                         output_commit_title(iter->item);
1254         }
1255
1256         merged_common_ancestors = pop_commit(&ca);
1257         if (merged_common_ancestors == NULL) {
1258                 /* if there is no common ancestor, make an empty tree */
1259                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1260
1261                 tree->object.parsed = 1;
1262                 tree->object.type = OBJ_TREE;
1263                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1264                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1265         }
1266
1267         for (iter = ca; iter; iter = iter->next) {
1268                 call_depth++;
1269                 /*
1270                  * When the merge fails, the result contains files
1271                  * with conflict markers. The cleanness flag is
1272                  * ignored, it was never actually used, as result of
1273                  * merge_trees has always overwritten it: the committed
1274                  * "conflicts" were already resolved.
1275                  */
1276                 discard_cache();
1277                 merge_recursive(merged_common_ancestors, iter->item,
1278                                 "Temporary merge branch 1",
1279                                 "Temporary merge branch 2",
1280                                 NULL,
1281                                 &merged_common_ancestors);
1282                 call_depth--;
1283
1284                 if (!merged_common_ancestors)
1285                         die("merge returned no commit");
1286         }
1287
1288         discard_cache();
1289         if (!call_depth) {
1290                 read_cache();
1291                 index_only = 0;
1292         } else
1293                 index_only = 1;
1294
1295         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1296                             branch1, branch2, &mrtree);
1297
1298         if (index_only) {
1299                 *result = make_virtual_commit(mrtree, "merged tree");
1300                 commit_list_insert(h1, &(*result)->parents);
1301                 commit_list_insert(h2, &(*result)->parents->next);
1302         }
1303         flush_output();
1304         return clean;
1305 }
1306
1307 static const char *better_branch_name(const char *branch)
1308 {
1309         static char githead_env[8 + 40 + 1];
1310         char *name;
1311
1312         if (strlen(branch) != 40)
1313                 return branch;
1314         sprintf(githead_env, "GITHEAD_%s", branch);
1315         name = getenv(githead_env);
1316         return name ? name : branch;
1317 }
1318
1319 static struct commit *get_ref(const char *ref)
1320 {
1321         unsigned char sha1[20];
1322         struct object *object;
1323
1324         if (get_sha1(ref, sha1))
1325                 die("Could not resolve ref '%s'", ref);
1326         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1327         if (!object)
1328                 return NULL;
1329         if (object->type == OBJ_TREE)
1330                 return make_virtual_commit((struct tree*)object,
1331                         better_branch_name(ref));
1332         if (object->type != OBJ_COMMIT)
1333                 return NULL;
1334         if (parse_commit((struct commit *)object))
1335                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1336         return (struct commit *)object;
1337 }
1338
1339 static int merge_config(const char *var, const char *value)
1340 {
1341         if (!strcasecmp(var, "merge.verbosity")) {
1342                 verbosity = git_config_int(var, value);
1343                 return 0;
1344         }
1345         if (!strcasecmp(var, "diff.renamelimit")) {
1346                 rename_limit = git_config_int(var, value);
1347                 return 0;
1348         }
1349         return git_default_config(var, value);
1350 }
1351
1352 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1353 {
1354         static const char *bases[20];
1355         static unsigned bases_count = 0;
1356         int i, clean;
1357         const char *branch1, *branch2;
1358         struct commit *result, *h1, *h2;
1359         struct commit_list *ca = NULL;
1360         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1361         int index_fd;
1362
1363         if (argv[0]) {
1364                 int namelen = strlen(argv[0]);
1365                 if (8 < namelen &&
1366                     !strcmp(argv[0] + namelen - 8, "-subtree"))
1367                         subtree_merge = 1;
1368         }
1369
1370         git_config(merge_config);
1371         if (getenv("GIT_MERGE_VERBOSITY"))
1372                 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1373
1374         if (argc < 4)
1375                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1376
1377         for (i = 1; i < argc; ++i) {
1378                 if (!strcmp(argv[i], "--"))
1379                         break;
1380                 if (bases_count < sizeof(bases)/sizeof(*bases))
1381                         bases[bases_count++] = argv[i];
1382         }
1383         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1384                 die("Not handling anything other than two heads merge.");
1385         if (verbosity >= 5)
1386                 buffer_output = 0;
1387
1388         branch1 = argv[++i];
1389         branch2 = argv[++i];
1390
1391         h1 = get_ref(branch1);
1392         h2 = get_ref(branch2);
1393
1394         branch1 = better_branch_name(branch1);
1395         branch2 = better_branch_name(branch2);
1396
1397         if (show(3))
1398                 printf("Merging %s with %s\n", branch1, branch2);
1399
1400         index_fd = hold_locked_index(lock, 1);
1401
1402         for (i = 0; i < bases_count; i++) {
1403                 struct commit *ancestor = get_ref(bases[i]);
1404                 ca = commit_list_insert(ancestor, &ca);
1405         }
1406         clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1407
1408         if (active_cache_changed &&
1409             (write_cache(index_fd, active_cache, active_nr) ||
1410              commit_locked_index(lock)))
1411                         die ("unable to write %s", get_index_file());
1412
1413         return clean ? 0: 1;
1414 }