diff --color-words: bit of clean-up
[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 "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 "string-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "attr.h"
20 #include "merge-recursive.h"
21 #include "dir.h"
22
23 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
24 {
25         unsigned char shifted[20];
26
27         /*
28          * NEEDSWORK: this limits the recursion depth to hardcoded
29          * value '2' to avoid excessive overhead.
30          */
31         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
32         if (!hashcmp(two->object.sha1, shifted))
33                 return two;
34         return lookup_tree(shifted);
35 }
36
37 /*
38  * A virtual commit has (const char *)commit->util set to the name.
39  */
40
41 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
42 {
43         struct commit *commit = xcalloc(1, sizeof(struct commit));
44         commit->tree = tree;
45         commit->util = (void*)comment;
46         /* avoid warnings */
47         commit->object.parsed = 1;
48         return commit;
49 }
50
51 /*
52  * Since we use get_tree_entry(), which does not put the read object into
53  * the object pool, we cannot rely on a == b.
54  */
55 static int sha_eq(const unsigned char *a, const unsigned char *b)
56 {
57         if (!a && !b)
58                 return 2;
59         return a && b && hashcmp(a, b) == 0;
60 }
61
62 /*
63  * Since we want to write the index eventually, we cannot reuse the index
64  * for these (temporary) data.
65  */
66 struct stage_data
67 {
68         struct
69         {
70                 unsigned mode;
71                 unsigned char sha[20];
72         } stages[4];
73         unsigned processed:1;
74 };
75
76 static int show(struct merge_options *o, int v)
77 {
78         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
79 }
80
81 static void flush_output(struct merge_options *o)
82 {
83         if (o->obuf.len) {
84                 fputs(o->obuf.buf, stdout);
85                 strbuf_reset(&o->obuf);
86         }
87 }
88
89 static void output(struct merge_options *o, int v, const char *fmt, ...)
90 {
91         int len;
92         va_list ap;
93
94         if (!show(o, v))
95                 return;
96
97         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
98         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
99         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
100
101         va_start(ap, fmt);
102         len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
103         va_end(ap);
104
105         if (len < 0)
106                 len = 0;
107         if (len >= strbuf_avail(&o->obuf)) {
108                 strbuf_grow(&o->obuf, len + 2);
109                 va_start(ap, fmt);
110                 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
111                 va_end(ap);
112                 if (len >= strbuf_avail(&o->obuf)) {
113                         die("this should not happen, your snprintf is broken");
114                 }
115         }
116         strbuf_setlen(&o->obuf, o->obuf.len + len);
117         strbuf_add(&o->obuf, "\n", 1);
118         if (!o->buffer_output)
119                 flush_output(o);
120 }
121
122 static void output_commit_title(struct merge_options *o, struct commit *commit)
123 {
124         int i;
125         flush_output(o);
126         for (i = o->call_depth; i--;)
127                 fputs("  ", stdout);
128         if (commit->util)
129                 printf("virtual %s\n", (char *)commit->util);
130         else {
131                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
132                 if (parse_commit(commit) != 0)
133                         printf("(bad commit)\n");
134                 else {
135                         const char *s;
136                         int len;
137                         for (s = commit->buffer; *s; s++)
138                                 if (*s == '\n' && s[1] == '\n') {
139                                         s += 2;
140                                         break;
141                                 }
142                         for (len = 0; s[len] && '\n' != s[len]; len++)
143                                 ; /* do nothing */
144                         printf("%.*s\n", len, s);
145                 }
146         }
147 }
148
149 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
150                 const char *path, int stage, int refresh, int options)
151 {
152         struct cache_entry *ce;
153         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
154         if (!ce)
155                 return error("addinfo_cache failed for path '%s'", path);
156         return add_cache_entry(ce, options);
157 }
158
159 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
160 {
161         parse_tree(tree);
162         init_tree_desc(desc, tree->buffer, tree->size);
163 }
164
165 static int git_merge_trees(int index_only,
166                            struct tree *common,
167                            struct tree *head,
168                            struct tree *merge)
169 {
170         int rc;
171         struct tree_desc t[3];
172         struct unpack_trees_options opts;
173         static const struct unpack_trees_error_msgs msgs = {
174                 /* would_overwrite */
175                 "Your local changes to '%s' would be overwritten by merge.  Aborting.",
176                 /* not_uptodate_file */
177                 "Your local changes to '%s' would be overwritten by merge.  Aborting.",
178                 /* not_uptodate_dir */
179                 "Updating '%s' would lose untracked files in it.  Aborting.",
180                 /* would_lose_untracked */
181                 "Untracked working tree file '%s' would be %s by merge.  Aborting",
182                 /* bind_overlap -- will not happen here */
183                 NULL,
184         };
185
186         memset(&opts, 0, sizeof(opts));
187         if (index_only)
188                 opts.index_only = 1;
189         else
190                 opts.update = 1;
191         opts.merge = 1;
192         opts.head_idx = 2;
193         opts.fn = threeway_merge;
194         opts.src_index = &the_index;
195         opts.dst_index = &the_index;
196         opts.msgs = msgs;
197
198         init_tree_desc_from_tree(t+0, common);
199         init_tree_desc_from_tree(t+1, head);
200         init_tree_desc_from_tree(t+2, merge);
201
202         rc = unpack_trees(3, t, &opts);
203         cache_tree_free(&active_cache_tree);
204         return rc;
205 }
206
207 struct tree *write_tree_from_memory(struct merge_options *o)
208 {
209         struct tree *result = NULL;
210
211         if (unmerged_cache()) {
212                 int i;
213                 output(o, 0, "There are unmerged index entries:");
214                 for (i = 0; i < active_nr; i++) {
215                         struct cache_entry *ce = active_cache[i];
216                         if (ce_stage(ce))
217                                 output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
218                 }
219                 return NULL;
220         }
221
222         if (!active_cache_tree)
223                 active_cache_tree = cache_tree();
224
225         if (!cache_tree_fully_valid(active_cache_tree) &&
226             cache_tree_update(active_cache_tree,
227                               active_cache, active_nr, 0, 0) < 0)
228                 die("error building trees");
229
230         result = lookup_tree(active_cache_tree->sha1);
231
232         return result;
233 }
234
235 static int save_files_dirs(const unsigned char *sha1,
236                 const char *base, int baselen, const char *path,
237                 unsigned int mode, int stage, void *context)
238 {
239         int len = strlen(path);
240         char *newpath = xmalloc(baselen + len + 1);
241         struct merge_options *o = context;
242
243         memcpy(newpath, base, baselen);
244         memcpy(newpath + baselen, path, len);
245         newpath[baselen + len] = '\0';
246
247         if (S_ISDIR(mode))
248                 string_list_insert(newpath, &o->current_directory_set);
249         else
250                 string_list_insert(newpath, &o->current_file_set);
251         free(newpath);
252
253         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
254 }
255
256 static int get_files_dirs(struct merge_options *o, struct tree *tree)
257 {
258         int n;
259         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
260                 return 0;
261         n = o->current_file_set.nr + o->current_directory_set.nr;
262         return n;
263 }
264
265 /*
266  * Returns an index_entry instance which doesn't have to correspond to
267  * a real cache entry in Git's index.
268  */
269 static struct stage_data *insert_stage_data(const char *path,
270                 struct tree *o, struct tree *a, struct tree *b,
271                 struct string_list *entries)
272 {
273         struct string_list_item *item;
274         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
275         get_tree_entry(o->object.sha1, path,
276                         e->stages[1].sha, &e->stages[1].mode);
277         get_tree_entry(a->object.sha1, path,
278                         e->stages[2].sha, &e->stages[2].mode);
279         get_tree_entry(b->object.sha1, path,
280                         e->stages[3].sha, &e->stages[3].mode);
281         item = string_list_insert(path, entries);
282         item->util = e;
283         return e;
284 }
285
286 /*
287  * Create a dictionary mapping file names to stage_data objects. The
288  * dictionary contains one entry for every path with a non-zero stage entry.
289  */
290 static struct string_list *get_unmerged(void)
291 {
292         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
293         int i;
294
295         unmerged->strdup_strings = 1;
296
297         for (i = 0; i < active_nr; i++) {
298                 struct string_list_item *item;
299                 struct stage_data *e;
300                 struct cache_entry *ce = active_cache[i];
301                 if (!ce_stage(ce))
302                         continue;
303
304                 item = string_list_lookup(ce->name, unmerged);
305                 if (!item) {
306                         item = string_list_insert(ce->name, unmerged);
307                         item->util = xcalloc(1, sizeof(struct stage_data));
308                 }
309                 e = item->util;
310                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
311                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
312         }
313
314         return unmerged;
315 }
316
317 struct rename
318 {
319         struct diff_filepair *pair;
320         struct stage_data *src_entry;
321         struct stage_data *dst_entry;
322         unsigned processed:1;
323 };
324
325 /*
326  * Get information of all renames which occurred between 'o_tree' and
327  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
328  * 'b_tree') to be able to associate the correct cache entries with
329  * the rename information. 'tree' is always equal to either a_tree or b_tree.
330  */
331 static struct string_list *get_renames(struct merge_options *o,
332                                        struct tree *tree,
333                                        struct tree *o_tree,
334                                        struct tree *a_tree,
335                                        struct tree *b_tree,
336                                        struct string_list *entries)
337 {
338         int i;
339         struct string_list *renames;
340         struct diff_options opts;
341
342         renames = xcalloc(1, sizeof(struct string_list));
343         diff_setup(&opts);
344         DIFF_OPT_SET(&opts, RECURSIVE);
345         opts.detect_rename = DIFF_DETECT_RENAME;
346         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
347                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
348                             500;
349         opts.warn_on_too_large_rename = 1;
350         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
351         if (diff_setup_done(&opts) < 0)
352                 die("diff setup failed");
353         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
354         diffcore_std(&opts);
355         for (i = 0; i < diff_queued_diff.nr; ++i) {
356                 struct string_list_item *item;
357                 struct rename *re;
358                 struct diff_filepair *pair = diff_queued_diff.queue[i];
359                 if (pair->status != 'R') {
360                         diff_free_filepair(pair);
361                         continue;
362                 }
363                 re = xmalloc(sizeof(*re));
364                 re->processed = 0;
365                 re->pair = pair;
366                 item = string_list_lookup(re->pair->one->path, entries);
367                 if (!item)
368                         re->src_entry = insert_stage_data(re->pair->one->path,
369                                         o_tree, a_tree, b_tree, entries);
370                 else
371                         re->src_entry = item->util;
372
373                 item = string_list_lookup(re->pair->two->path, entries);
374                 if (!item)
375                         re->dst_entry = insert_stage_data(re->pair->two->path,
376                                         o_tree, a_tree, b_tree, entries);
377                 else
378                         re->dst_entry = item->util;
379                 item = string_list_insert(pair->one->path, renames);
380                 item->util = re;
381         }
382         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
383         diff_queued_diff.nr = 0;
384         diff_flush(&opts);
385         return renames;
386 }
387
388 static int update_stages(const char *path, struct diff_filespec *o,
389                          struct diff_filespec *a, struct diff_filespec *b,
390                          int clear)
391 {
392         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
393         if (clear)
394                 if (remove_file_from_cache(path))
395                         return -1;
396         if (o)
397                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
398                         return -1;
399         if (a)
400                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
401                         return -1;
402         if (b)
403                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
404                         return -1;
405         return 0;
406 }
407
408 static int remove_file(struct merge_options *o, int clean,
409                        const char *path, int no_wd)
410 {
411         int update_cache = o->call_depth || clean;
412         int update_working_directory = !o->call_depth && !no_wd;
413
414         if (update_cache) {
415                 if (remove_file_from_cache(path))
416                         return -1;
417         }
418         if (update_working_directory) {
419                 if (remove_path(path) && errno != ENOENT)
420                         return -1;
421         }
422         return 0;
423 }
424
425 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
426 {
427         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
428         int suffix = 0;
429         struct stat st;
430         char *p = newpath + strlen(path);
431         strcpy(newpath, path);
432         *(p++) = '~';
433         strcpy(p, branch);
434         for (; *p; ++p)
435                 if ('/' == *p)
436                         *p = '_';
437         while (string_list_has_string(&o->current_file_set, newpath) ||
438                string_list_has_string(&o->current_directory_set, newpath) ||
439                lstat(newpath, &st) == 0)
440                 sprintf(p, "_%d", suffix++);
441
442         string_list_insert(newpath, &o->current_file_set);
443         return newpath;
444 }
445
446 static void flush_buffer(int fd, const char *buf, unsigned long size)
447 {
448         while (size > 0) {
449                 long ret = write_in_full(fd, buf, size);
450                 if (ret < 0) {
451                         /* Ignore epipe */
452                         if (errno == EPIPE)
453                                 break;
454                         die_errno("merge-recursive");
455                 } else if (!ret) {
456                         die("merge-recursive: disk full?");
457                 }
458                 size -= ret;
459                 buf += ret;
460         }
461 }
462
463 static int would_lose_untracked(const char *path)
464 {
465         int pos = cache_name_pos(path, strlen(path));
466
467         if (pos < 0)
468                 pos = -1 - pos;
469         while (pos < active_nr &&
470                !strcmp(path, active_cache[pos]->name)) {
471                 /*
472                  * If stage #0, it is definitely tracked.
473                  * If it has stage #2 then it was tracked
474                  * before this merge started.  All other
475                  * cases the path was not tracked.
476                  */
477                 switch (ce_stage(active_cache[pos])) {
478                 case 0:
479                 case 2:
480                         return 0;
481                 }
482                 pos++;
483         }
484         return file_exists(path);
485 }
486
487 static int make_room_for_path(const char *path)
488 {
489         int status;
490         const char *msg = "failed to create path '%s'%s";
491
492         status = safe_create_leading_directories_const(path);
493         if (status) {
494                 if (status == -3) {
495                         /* something else exists */
496                         error(msg, path, ": perhaps a D/F conflict?");
497                         return -1;
498                 }
499                 die(msg, path, "");
500         }
501
502         /*
503          * Do not unlink a file in the work tree if we are not
504          * tracking it.
505          */
506         if (would_lose_untracked(path))
507                 return error("refusing to lose untracked file at '%s'",
508                              path);
509
510         /* Successful unlink is good.. */
511         if (!unlink(path))
512                 return 0;
513         /* .. and so is no existing file */
514         if (errno == ENOENT)
515                 return 0;
516         /* .. but not some other error (who really cares what?) */
517         return error(msg, path, ": perhaps a D/F conflict?");
518 }
519
520 static void update_file_flags(struct merge_options *o,
521                               const unsigned char *sha,
522                               unsigned mode,
523                               const char *path,
524                               int update_cache,
525                               int update_wd)
526 {
527         if (o->call_depth)
528                 update_wd = 0;
529
530         if (update_wd) {
531                 enum object_type type;
532                 void *buf;
533                 unsigned long size;
534
535                 if (S_ISGITLINK(mode))
536                         /*
537                          * We may later decide to recursively descend into
538                          * the submodule directory and update its index
539                          * and/or work tree, but we do not do that now.
540                          */
541                         goto update_index;
542
543                 buf = read_sha1_file(sha, &type, &size);
544                 if (!buf)
545                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
546                 if (type != OBJ_BLOB)
547                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
548                 if (S_ISREG(mode)) {
549                         struct strbuf strbuf = STRBUF_INIT;
550                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
551                                 free(buf);
552                                 size = strbuf.len;
553                                 buf = strbuf_detach(&strbuf, NULL);
554                         }
555                 }
556
557                 if (make_room_for_path(path) < 0) {
558                         update_wd = 0;
559                         free(buf);
560                         goto update_index;
561                 }
562                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
563                         int fd;
564                         if (mode & 0100)
565                                 mode = 0777;
566                         else
567                                 mode = 0666;
568                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
569                         if (fd < 0)
570                                 die_errno("failed to open '%s'", path);
571                         flush_buffer(fd, buf, size);
572                         close(fd);
573                 } else if (S_ISLNK(mode)) {
574                         char *lnk = xmemdupz(buf, size);
575                         safe_create_leading_directories_const(path);
576                         unlink(path);
577                         if (symlink(lnk, path))
578                                 die_errno("failed to symlink '%s'", path);
579                         free(lnk);
580                 } else
581                         die("do not know what to do with %06o %s '%s'",
582                             mode, sha1_to_hex(sha), path);
583                 free(buf);
584         }
585  update_index:
586         if (update_cache)
587                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
588 }
589
590 static void update_file(struct merge_options *o,
591                         int clean,
592                         const unsigned char *sha,
593                         unsigned mode,
594                         const char *path)
595 {
596         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
597 }
598
599 /* Low level file merging, update and removal */
600
601 struct merge_file_info
602 {
603         unsigned char sha[20];
604         unsigned mode;
605         unsigned clean:1,
606                  merge:1;
607 };
608
609 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
610 {
611         unsigned long size;
612         enum object_type type;
613
614         if (!hashcmp(sha1, null_sha1)) {
615                 mm->ptr = xstrdup("");
616                 mm->size = 0;
617                 return;
618         }
619
620         mm->ptr = read_sha1_file(sha1, &type, &size);
621         if (!mm->ptr || type != OBJ_BLOB)
622                 die("unable to read blob object %s", sha1_to_hex(sha1));
623         mm->size = size;
624 }
625
626 static int merge_3way(struct merge_options *o,
627                       mmbuffer_t *result_buf,
628                       struct diff_filespec *one,
629                       struct diff_filespec *a,
630                       struct diff_filespec *b,
631                       const char *branch1,
632                       const char *branch2)
633 {
634         mmfile_t orig, src1, src2;
635         char *name1, *name2;
636         int merge_status;
637
638         if (strcmp(a->path, b->path)) {
639                 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
640                 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
641         } else {
642                 name1 = xstrdup(mkpath("%s", branch1));
643                 name2 = xstrdup(mkpath("%s", branch2));
644         }
645
646         fill_mm(one->sha1, &orig);
647         fill_mm(a->sha1, &src1);
648         fill_mm(b->sha1, &src2);
649
650         merge_status = ll_merge(result_buf, a->path, &orig,
651                                 &src1, name1, &src2, name2,
652                                 o->call_depth);
653
654         free(name1);
655         free(name2);
656         free(orig.ptr);
657         free(src1.ptr);
658         free(src2.ptr);
659         return merge_status;
660 }
661
662 static struct merge_file_info merge_file(struct merge_options *o,
663                                          struct diff_filespec *one,
664                                          struct diff_filespec *a,
665                                          struct diff_filespec *b,
666                                          const char *branch1,
667                                          const char *branch2)
668 {
669         struct merge_file_info result;
670         result.merge = 0;
671         result.clean = 1;
672
673         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
674                 result.clean = 0;
675                 if (S_ISREG(a->mode)) {
676                         result.mode = a->mode;
677                         hashcpy(result.sha, a->sha1);
678                 } else {
679                         result.mode = b->mode;
680                         hashcpy(result.sha, b->sha1);
681                 }
682         } else {
683                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
684                         result.merge = 1;
685
686                 /*
687                  * Merge modes
688                  */
689                 if (a->mode == b->mode || a->mode == one->mode)
690                         result.mode = b->mode;
691                 else {
692                         result.mode = a->mode;
693                         if (b->mode != one->mode) {
694                                 result.clean = 0;
695                                 result.merge = 1;
696                         }
697                 }
698
699                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
700                         hashcpy(result.sha, b->sha1);
701                 else if (sha_eq(b->sha1, one->sha1))
702                         hashcpy(result.sha, a->sha1);
703                 else if (S_ISREG(a->mode)) {
704                         mmbuffer_t result_buf;
705                         int merge_status;
706
707                         merge_status = merge_3way(o, &result_buf, one, a, b,
708                                                   branch1, branch2);
709
710                         if ((merge_status < 0) || !result_buf.ptr)
711                                 die("Failed to execute internal merge");
712
713                         if (write_sha1_file(result_buf.ptr, result_buf.size,
714                                             blob_type, result.sha))
715                                 die("Unable to add %s to database",
716                                     a->path);
717
718                         free(result_buf.ptr);
719                         result.clean = (merge_status == 0);
720                 } else if (S_ISGITLINK(a->mode)) {
721                         result.clean = 0;
722                         hashcpy(result.sha, a->sha1);
723                 } else if (S_ISLNK(a->mode)) {
724                         hashcpy(result.sha, a->sha1);
725
726                         if (!sha_eq(a->sha1, b->sha1))
727                                 result.clean = 0;
728                 } else {
729                         die("unsupported object type in the tree");
730                 }
731         }
732
733         return result;
734 }
735
736 static void conflict_rename_rename(struct merge_options *o,
737                                    struct rename *ren1,
738                                    const char *branch1,
739                                    struct rename *ren2,
740                                    const char *branch2)
741 {
742         char *del[2];
743         int delp = 0;
744         const char *ren1_dst = ren1->pair->two->path;
745         const char *ren2_dst = ren2->pair->two->path;
746         const char *dst_name1 = ren1_dst;
747         const char *dst_name2 = ren2_dst;
748         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
749                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
750                 output(o, 1, "%s is a directory in %s adding as %s instead",
751                        ren1_dst, branch2, dst_name1);
752                 remove_file(o, 0, ren1_dst, 0);
753         }
754         if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
755                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
756                 output(o, 1, "%s is a directory in %s adding as %s instead",
757                        ren2_dst, branch1, dst_name2);
758                 remove_file(o, 0, ren2_dst, 0);
759         }
760         if (o->call_depth) {
761                 remove_file_from_cache(dst_name1);
762                 remove_file_from_cache(dst_name2);
763                 /*
764                  * Uncomment to leave the conflicting names in the resulting tree
765                  *
766                  * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
767                  * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
768                  */
769         } else {
770                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
771                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
772         }
773         while (delp--)
774                 free(del[delp]);
775 }
776
777 static void conflict_rename_dir(struct merge_options *o,
778                                 struct rename *ren1,
779                                 const char *branch1)
780 {
781         char *new_path = unique_path(o, ren1->pair->two->path, branch1);
782         output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
783         remove_file(o, 0, ren1->pair->two->path, 0);
784         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
785         free(new_path);
786 }
787
788 static void conflict_rename_rename_2(struct merge_options *o,
789                                      struct rename *ren1,
790                                      const char *branch1,
791                                      struct rename *ren2,
792                                      const char *branch2)
793 {
794         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
795         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
796         output(o, 1, "Renaming %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(o, 0, ren1->pair->two->path, 0);
800         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
801         update_file(o, 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 merge_options *o,
807                            struct string_list *a_renames,
808                            struct string_list *b_renames)
809 {
810         int clean_merge = 1, i, j;
811         struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
812         const struct rename *sre;
813
814         for (i = 0; i < a_renames->nr; i++) {
815                 sre = a_renames->items[i].util;
816                 string_list_insert(sre->pair->two->path, &a_by_dst)->util
817                         = sre->dst_entry;
818         }
819         for (i = 0; i < b_renames->nr; i++) {
820                 sre = b_renames->items[i].util;
821                 string_list_insert(sre->pair->two->path, &b_by_dst)->util
822                         = sre->dst_entry;
823         }
824
825         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
826                 char *src;
827                 struct string_list *renames1, *renames2Dst;
828                 struct rename *ren1 = NULL, *ren2 = NULL;
829                 const char *branch1, *branch2;
830                 const char *ren1_src, *ren1_dst;
831
832                 if (i >= a_renames->nr) {
833                         ren2 = b_renames->items[j++].util;
834                 } else if (j >= b_renames->nr) {
835                         ren1 = a_renames->items[i++].util;
836                 } else {
837                         int compare = strcmp(a_renames->items[i].string,
838                                              b_renames->items[j].string);
839                         if (compare <= 0)
840                                 ren1 = a_renames->items[i++].util;
841                         if (compare >= 0)
842                                 ren2 = b_renames->items[j++].util;
843                 }
844
845                 /* TODO: refactor, so that 1/2 are not needed */
846                 if (ren1) {
847                         renames1 = a_renames;
848                         renames2Dst = &b_by_dst;
849                         branch1 = o->branch1;
850                         branch2 = o->branch2;
851                 } else {
852                         struct rename *tmp;
853                         renames1 = b_renames;
854                         renames2Dst = &a_by_dst;
855                         branch1 = o->branch2;
856                         branch2 = o->branch1;
857                         tmp = ren2;
858                         ren2 = ren1;
859                         ren1 = tmp;
860                 }
861                 src = ren1->pair->one->path;
862
863                 ren1->dst_entry->processed = 1;
864                 ren1->src_entry->processed = 1;
865
866                 if (ren1->processed)
867                         continue;
868                 ren1->processed = 1;
869
870                 ren1_src = ren1->pair->one->path;
871                 ren1_dst = ren1->pair->two->path;
872
873                 if (ren2) {
874                         const char *ren2_src = ren2->pair->one->path;
875                         const char *ren2_dst = ren2->pair->two->path;
876                         /* Renamed in 1 and renamed in 2 */
877                         if (strcmp(ren1_src, ren2_src) != 0)
878                                 die("ren1.src != ren2.src");
879                         ren2->dst_entry->processed = 1;
880                         ren2->processed = 1;
881                         if (strcmp(ren1_dst, ren2_dst) != 0) {
882                                 clean_merge = 0;
883                                 output(o, 1, "CONFLICT (rename/rename): "
884                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
885                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
886                                        src, ren1_dst, branch1,
887                                        src, ren2_dst, branch2,
888                                        o->call_depth ? " (left unresolved)": "");
889                                 if (o->call_depth) {
890                                         remove_file_from_cache(src);
891                                         update_file(o, 0, ren1->pair->one->sha1,
892                                                     ren1->pair->one->mode, src);
893                                 }
894                                 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
895                         } else {
896                                 struct merge_file_info mfi;
897                                 remove_file(o, 1, ren1_src, 1);
898                                 mfi = merge_file(o,
899                                                  ren1->pair->one,
900                                                  ren1->pair->two,
901                                                  ren2->pair->two,
902                                                  branch1,
903                                                  branch2);
904                                 if (mfi.merge || !mfi.clean)
905                                         output(o, 1, "Renaming %s->%s", src, ren1_dst);
906
907                                 if (mfi.merge)
908                                         output(o, 2, "Auto-merging %s", ren1_dst);
909
910                                 if (!mfi.clean) {
911                                         output(o, 1, "CONFLICT (content): merge conflict in %s",
912                                                ren1_dst);
913                                         clean_merge = 0;
914
915                                         if (!o->call_depth)
916                                                 update_stages(ren1_dst,
917                                                               ren1->pair->one,
918                                                               ren1->pair->two,
919                                                               ren2->pair->two,
920                                                               1 /* clear */);
921                                 }
922                                 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
923                         }
924                 } else {
925                         /* Renamed in 1, maybe changed in 2 */
926                         struct string_list_item *item;
927                         /* we only use sha1 and mode of these */
928                         struct diff_filespec src_other, dst_other;
929                         int try_merge, stage = a_renames == renames1 ? 3: 2;
930
931                         remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
932
933                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
934                         src_other.mode = ren1->src_entry->stages[stage].mode;
935                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
936                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
937
938                         try_merge = 0;
939
940                         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
941                                 clean_merge = 0;
942                                 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
943                                        " directory %s added in %s",
944                                        ren1_src, ren1_dst, branch1,
945                                        ren1_dst, branch2);
946                                 conflict_rename_dir(o, ren1, branch1);
947                         } else if (sha_eq(src_other.sha1, null_sha1)) {
948                                 clean_merge = 0;
949                                 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
950                                        "and deleted in %s",
951                                        ren1_src, ren1_dst, branch1,
952                                        branch2);
953                                 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
954                                 if (!o->call_depth)
955                                         update_stages(ren1_dst, NULL,
956                                                         branch1 == o->branch1 ?
957                                                         ren1->pair->two : NULL,
958                                                         branch1 == o->branch1 ?
959                                                         NULL : ren1->pair->two, 1);
960                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
961                                 const char *new_path;
962                                 clean_merge = 0;
963                                 try_merge = 1;
964                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
965                                        "%s added in %s",
966                                        ren1_src, ren1_dst, branch1,
967                                        ren1_dst, branch2);
968                                 if (o->call_depth) {
969                                         struct merge_file_info mfi;
970                                         struct diff_filespec one, a, b;
971
972                                         one.path = a.path = b.path =
973                                                 (char *)ren1_dst;
974                                         hashcpy(one.sha1, null_sha1);
975                                         one.mode = 0;
976                                         hashcpy(a.sha1, ren1->pair->two->sha1);
977                                         a.mode = ren1->pair->two->mode;
978                                         hashcpy(b.sha1, dst_other.sha1);
979                                         b.mode = dst_other.mode;
980                                         mfi = merge_file(o, &one, &a, &b,
981                                                          branch1,
982                                                          branch2);
983                                         output(o, 1, "Adding merged %s", ren1_dst);
984                                         update_file(o, 0,
985                                                     mfi.sha,
986                                                     mfi.mode,
987                                                     ren1_dst);
988                                 } else {
989                                         new_path = unique_path(o, ren1_dst, branch2);
990                                         output(o, 1, "Adding as %s instead", new_path);
991                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
992                                 }
993                         } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
994                                 ren2 = item->util;
995                                 clean_merge = 0;
996                                 ren2->processed = 1;
997                                 output(o, 1, "CONFLICT (rename/rename): "
998                                        "Rename %s->%s in %s. "
999                                        "Rename %s->%s in %s",
1000                                        ren1_src, ren1_dst, branch1,
1001                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
1002                                 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
1003                         } else
1004                                 try_merge = 1;
1005
1006                         if (try_merge) {
1007                                 struct diff_filespec *one, *a, *b;
1008                                 struct merge_file_info mfi;
1009                                 src_other.path = (char *)ren1_src;
1010
1011                                 one = ren1->pair->one;
1012                                 if (a_renames == renames1) {
1013                                         a = ren1->pair->two;
1014                                         b = &src_other;
1015                                 } else {
1016                                         b = ren1->pair->two;
1017                                         a = &src_other;
1018                                 }
1019                                 mfi = merge_file(o, one, a, b,
1020                                                 o->branch1, o->branch2);
1021
1022                                 if (mfi.clean &&
1023                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1024                                     mfi.mode == ren1->pair->two->mode)
1025                                         /*
1026                                          * This messaged is part of
1027                                          * t6022 test. If you change
1028                                          * it update the test too.
1029                                          */
1030                                         output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
1031                                 else {
1032                                         if (mfi.merge || !mfi.clean)
1033                                                 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
1034                                         if (mfi.merge)
1035                                                 output(o, 2, "Auto-merging %s", ren1_dst);
1036                                         if (!mfi.clean) {
1037                                                 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
1038                                                        ren1_dst);
1039                                                 clean_merge = 0;
1040
1041                                                 if (!o->call_depth)
1042                                                         update_stages(ren1_dst,
1043                                                                       one, a, b, 1);
1044                                         }
1045                                         update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1046                                 }
1047                         }
1048                 }
1049         }
1050         string_list_clear(&a_by_dst, 0);
1051         string_list_clear(&b_by_dst, 0);
1052
1053         return clean_merge;
1054 }
1055
1056 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1057 {
1058         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1059 }
1060
1061 /* Per entry merge function */
1062 static int process_entry(struct merge_options *o,
1063                          const char *path, struct stage_data *entry)
1064 {
1065         /*
1066         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1067         print_index_entry("\tpath: ", entry);
1068         */
1069         int clean_merge = 1;
1070         unsigned o_mode = entry->stages[1].mode;
1071         unsigned a_mode = entry->stages[2].mode;
1072         unsigned b_mode = entry->stages[3].mode;
1073         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1074         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1075         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1076
1077         if (o_sha && (!a_sha || !b_sha)) {
1078                 /* Case A: Deleted in one */
1079                 if ((!a_sha && !b_sha) ||
1080                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1081                     (!a_sha && sha_eq(b_sha, o_sha))) {
1082                         /* Deleted in both or deleted in one and
1083                          * unchanged in the other */
1084                         if (a_sha)
1085                                 output(o, 2, "Removing %s", path);
1086                         /* do not touch working file if it did not exist */
1087                         remove_file(o, 1, path, !a_sha);
1088                 } else {
1089                         /* Deleted in one and changed in the other */
1090                         clean_merge = 0;
1091                         if (!a_sha) {
1092                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1093                                        "and modified in %s. Version %s of %s left in tree.",
1094                                        path, o->branch1,
1095                                        o->branch2, o->branch2, path);
1096                                 update_file(o, 0, b_sha, b_mode, path);
1097                         } else {
1098                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1099                                        "and modified in %s. Version %s of %s left in tree.",
1100                                        path, o->branch2,
1101                                        o->branch1, o->branch1, path);
1102                                 update_file(o, 0, a_sha, a_mode, path);
1103                         }
1104                 }
1105
1106         } else if ((!o_sha && a_sha && !b_sha) ||
1107                    (!o_sha && !a_sha && b_sha)) {
1108                 /* Case B: Added in one. */
1109                 const char *add_branch;
1110                 const char *other_branch;
1111                 unsigned mode;
1112                 const unsigned char *sha;
1113                 const char *conf;
1114
1115                 if (a_sha) {
1116                         add_branch = o->branch1;
1117                         other_branch = o->branch2;
1118                         mode = a_mode;
1119                         sha = a_sha;
1120                         conf = "file/directory";
1121                 } else {
1122                         add_branch = o->branch2;
1123                         other_branch = o->branch1;
1124                         mode = b_mode;
1125                         sha = b_sha;
1126                         conf = "directory/file";
1127                 }
1128                 if (string_list_has_string(&o->current_directory_set, path)) {
1129                         const char *new_path = unique_path(o, path, add_branch);
1130                         clean_merge = 0;
1131                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1132                                "Adding %s as %s",
1133                                conf, path, other_branch, path, new_path);
1134                         remove_file(o, 0, path, 0);
1135                         update_file(o, 0, sha, mode, new_path);
1136                 } else {
1137                         output(o, 2, "Adding %s", path);
1138                         update_file(o, 1, sha, mode, path);
1139                 }
1140         } else if (a_sha && b_sha) {
1141                 /* Case C: Added in both (check for same permissions) and */
1142                 /* case D: Modified in both, but differently. */
1143                 const char *reason = "content";
1144                 struct merge_file_info mfi;
1145                 struct diff_filespec one, a, b;
1146
1147                 if (!o_sha) {
1148                         reason = "add/add";
1149                         o_sha = (unsigned char *)null_sha1;
1150                 }
1151                 output(o, 2, "Auto-merging %s", path);
1152                 one.path = a.path = b.path = (char *)path;
1153                 hashcpy(one.sha1, o_sha);
1154                 one.mode = o_mode;
1155                 hashcpy(a.sha1, a_sha);
1156                 a.mode = a_mode;
1157                 hashcpy(b.sha1, b_sha);
1158                 b.mode = b_mode;
1159
1160                 mfi = merge_file(o, &one, &a, &b,
1161                                  o->branch1, o->branch2);
1162
1163                 clean_merge = mfi.clean;
1164                 if (!mfi.clean) {
1165                         if (S_ISGITLINK(mfi.mode))
1166                                 reason = "submodule";
1167                         output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1168                                         reason, path);
1169                 }
1170                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1171         } else if (!o_sha && !a_sha && !b_sha) {
1172                 /*
1173                  * this entry was deleted altogether. a_mode == 0 means
1174                  * we had that path and want to actively remove it.
1175                  */
1176                 remove_file(o, 1, path, !a_mode);
1177         } else
1178                 die("Fatal merge failure, shouldn't happen.");
1179
1180         return clean_merge;
1181 }
1182
1183 int merge_trees(struct merge_options *o,
1184                 struct tree *head,
1185                 struct tree *merge,
1186                 struct tree *common,
1187                 struct tree **result)
1188 {
1189         int code, clean;
1190
1191         if (o->subtree_merge) {
1192                 merge = shift_tree_object(head, merge);
1193                 common = shift_tree_object(head, common);
1194         }
1195
1196         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1197                 output(o, 0, "Already uptodate!");
1198                 *result = head;
1199                 return 1;
1200         }
1201
1202         code = git_merge_trees(o->call_depth, common, head, merge);
1203
1204         if (code != 0) {
1205                 if (show(o, 4) || o->call_depth)
1206                         die("merging of trees %s and %s failed",
1207                             sha1_to_hex(head->object.sha1),
1208                             sha1_to_hex(merge->object.sha1));
1209                 else
1210                         exit(128);
1211         }
1212
1213         if (unmerged_cache()) {
1214                 struct string_list *entries, *re_head, *re_merge;
1215                 int i;
1216                 string_list_clear(&o->current_file_set, 1);
1217                 string_list_clear(&o->current_directory_set, 1);
1218                 get_files_dirs(o, head);
1219                 get_files_dirs(o, merge);
1220
1221                 entries = get_unmerged();
1222                 re_head  = get_renames(o, head, common, head, merge, entries);
1223                 re_merge = get_renames(o, merge, common, head, merge, entries);
1224                 clean = process_renames(o, re_head, re_merge);
1225                 for (i = 0; i < entries->nr; i++) {
1226                         const char *path = entries->items[i].string;
1227                         struct stage_data *e = entries->items[i].util;
1228                         if (!e->processed
1229                                 && !process_entry(o, path, e))
1230                                 clean = 0;
1231                 }
1232
1233                 string_list_clear(re_merge, 0);
1234                 string_list_clear(re_head, 0);
1235                 string_list_clear(entries, 1);
1236
1237         }
1238         else
1239                 clean = 1;
1240
1241         if (o->call_depth)
1242                 *result = write_tree_from_memory(o);
1243
1244         return clean;
1245 }
1246
1247 static struct commit_list *reverse_commit_list(struct commit_list *list)
1248 {
1249         struct commit_list *next = NULL, *current, *backup;
1250         for (current = list; current; current = backup) {
1251                 backup = current->next;
1252                 current->next = next;
1253                 next = current;
1254         }
1255         return next;
1256 }
1257
1258 /*
1259  * Merge the commits h1 and h2, return the resulting virtual
1260  * commit object and a flag indicating the cleanness of the merge.
1261  */
1262 int merge_recursive(struct merge_options *o,
1263                     struct commit *h1,
1264                     struct commit *h2,
1265                     struct commit_list *ca,
1266                     struct commit **result)
1267 {
1268         struct commit_list *iter;
1269         struct commit *merged_common_ancestors;
1270         struct tree *mrtree = mrtree;
1271         int clean;
1272
1273         if (show(o, 4)) {
1274                 output(o, 4, "Merging:");
1275                 output_commit_title(o, h1);
1276                 output_commit_title(o, h2);
1277         }
1278
1279         if (!ca) {
1280                 ca = get_merge_bases(h1, h2, 1);
1281                 ca = reverse_commit_list(ca);
1282         }
1283
1284         if (show(o, 5)) {
1285                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1286                 for (iter = ca; iter; iter = iter->next)
1287                         output_commit_title(o, iter->item);
1288         }
1289
1290         merged_common_ancestors = pop_commit(&ca);
1291         if (merged_common_ancestors == NULL) {
1292                 /* if there is no common ancestor, make an empty tree */
1293                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1294
1295                 tree->object.parsed = 1;
1296                 tree->object.type = OBJ_TREE;
1297                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1298                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1299         }
1300
1301         for (iter = ca; iter; iter = iter->next) {
1302                 const char *saved_b1, *saved_b2;
1303                 o->call_depth++;
1304                 /*
1305                  * When the merge fails, the result contains files
1306                  * with conflict markers. The cleanness flag is
1307                  * ignored, it was never actually used, as result of
1308                  * merge_trees has always overwritten it: the committed
1309                  * "conflicts" were already resolved.
1310                  */
1311                 discard_cache();
1312                 saved_b1 = o->branch1;
1313                 saved_b2 = o->branch2;
1314                 o->branch1 = "Temporary merge branch 1";
1315                 o->branch2 = "Temporary merge branch 2";
1316                 merge_recursive(o, merged_common_ancestors, iter->item,
1317                                 NULL, &merged_common_ancestors);
1318                 o->branch1 = saved_b1;
1319                 o->branch2 = saved_b2;
1320                 o->call_depth--;
1321
1322                 if (!merged_common_ancestors)
1323                         die("merge returned no commit");
1324         }
1325
1326         discard_cache();
1327         if (!o->call_depth)
1328                 read_cache();
1329
1330         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1331                             &mrtree);
1332
1333         if (o->call_depth) {
1334                 *result = make_virtual_commit(mrtree, "merged tree");
1335                 commit_list_insert(h1, &(*result)->parents);
1336                 commit_list_insert(h2, &(*result)->parents->next);
1337         }
1338         flush_output(o);
1339         return clean;
1340 }
1341
1342 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1343 {
1344         struct object *object;
1345
1346         object = deref_tag(parse_object(sha1), name, strlen(name));
1347         if (!object)
1348                 return NULL;
1349         if (object->type == OBJ_TREE)
1350                 return make_virtual_commit((struct tree*)object, name);
1351         if (object->type != OBJ_COMMIT)
1352                 return NULL;
1353         if (parse_commit((struct commit *)object))
1354                 return NULL;
1355         return (struct commit *)object;
1356 }
1357
1358 int merge_recursive_generic(struct merge_options *o,
1359                             const unsigned char *head,
1360                             const unsigned char *merge,
1361                             int num_base_list,
1362                             const unsigned char **base_list,
1363                             struct commit **result)
1364 {
1365         int clean, index_fd;
1366         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1367         struct commit *head_commit = get_ref(head, o->branch1);
1368         struct commit *next_commit = get_ref(merge, o->branch2);
1369         struct commit_list *ca = NULL;
1370
1371         if (base_list) {
1372                 int i;
1373                 for (i = 0; i < num_base_list; ++i) {
1374                         struct commit *base;
1375                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1376                                 return error("Could not parse object '%s'",
1377                                         sha1_to_hex(base_list[i]));
1378                         commit_list_insert(base, &ca);
1379                 }
1380         }
1381
1382         index_fd = hold_locked_index(lock, 1);
1383         clean = merge_recursive(o, head_commit, next_commit, ca,
1384                         result);
1385         if (active_cache_changed &&
1386                         (write_cache(index_fd, active_cache, active_nr) ||
1387                          commit_locked_index(lock)))
1388                 return error("Unable to write index.");
1389
1390         return clean ? 0 : 1;
1391 }
1392
1393 static int merge_recursive_config(const char *var, const char *value, void *cb)
1394 {
1395         struct merge_options *o = cb;
1396         if (!strcasecmp(var, "merge.verbosity")) {
1397                 o->verbosity = git_config_int(var, value);
1398                 return 0;
1399         }
1400         if (!strcasecmp(var, "diff.renamelimit")) {
1401                 o->diff_rename_limit = git_config_int(var, value);
1402                 return 0;
1403         }
1404         if (!strcasecmp(var, "merge.renamelimit")) {
1405                 o->merge_rename_limit = git_config_int(var, value);
1406                 return 0;
1407         }
1408         return git_xmerge_config(var, value, cb);
1409 }
1410
1411 void init_merge_options(struct merge_options *o)
1412 {
1413         memset(o, 0, sizeof(struct merge_options));
1414         o->verbosity = 2;
1415         o->buffer_output = 1;
1416         o->diff_rename_limit = -1;
1417         o->merge_rename_limit = -1;
1418         git_config(merge_recursive_config, o);
1419         if (getenv("GIT_MERGE_VERBOSITY"))
1420                 o->verbosity =
1421                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1422         if (o->verbosity >= 5)
1423                 o->buffer_output = 0;
1424         strbuf_init(&o->obuf, 0);
1425         memset(&o->current_file_set, 0, sizeof(struct string_list));
1426         o->current_file_set.strdup_strings = 1;
1427         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1428         o->current_directory_set.strdup_strings = 1;
1429 }