Merge branch 'sb/plug-leaks'
[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 "advice.h"
7 #include "cache.h"
8 #include "cache-tree.h"
9 #include "commit.h"
10 #include "blob.h"
11 #include "builtin.h"
12 #include "tree-walk.h"
13 #include "diff.h"
14 #include "diffcore.h"
15 #include "tag.h"
16 #include "unpack-trees.h"
17 #include "string-list.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22 #include "dir.h"
23 #include "submodule.h"
24
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
26                                       const char *subtree_shift)
27 {
28         unsigned char shifted[20];
29
30         if (!*subtree_shift) {
31                 shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
32         } else {
33                 shift_tree_by(one->object.sha1, two->object.sha1, shifted,
34                               subtree_shift);
35         }
36         if (!hashcmp(two->object.sha1, shifted))
37                 return two;
38         return lookup_tree(shifted);
39 }
40
41 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
42 {
43         struct commit *commit = alloc_commit_node();
44         struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
45
46         desc->name = comment;
47         desc->obj = (struct object *)commit;
48         commit->tree = tree;
49         commit->util = desc;
50         commit->object.parsed = 1;
51         return commit;
52 }
53
54 /*
55  * Since we use get_tree_entry(), which does not put the read object into
56  * the object pool, we cannot rely on a == b.
57  */
58 static int sha_eq(const unsigned char *a, const unsigned char *b)
59 {
60         if (!a && !b)
61                 return 2;
62         return a && b && hashcmp(a, b) == 0;
63 }
64
65 enum rename_type {
66         RENAME_NORMAL = 0,
67         RENAME_DELETE,
68         RENAME_ONE_FILE_TO_ONE,
69         RENAME_ONE_FILE_TO_TWO,
70         RENAME_TWO_FILES_TO_ONE
71 };
72
73 struct rename_conflict_info {
74         enum rename_type rename_type;
75         struct diff_filepair *pair1;
76         struct diff_filepair *pair2;
77         const char *branch1;
78         const char *branch2;
79         struct stage_data *dst_entry1;
80         struct stage_data *dst_entry2;
81         struct diff_filespec ren1_other;
82         struct diff_filespec ren2_other;
83 };
84
85 /*
86  * Since we want to write the index eventually, we cannot reuse the index
87  * for these (temporary) data.
88  */
89 struct stage_data {
90         struct {
91                 unsigned mode;
92                 unsigned char sha[20];
93         } stages[4];
94         struct rename_conflict_info *rename_conflict_info;
95         unsigned processed:1;
96 };
97
98 static inline void setup_rename_conflict_info(enum rename_type rename_type,
99                                               struct diff_filepair *pair1,
100                                               struct diff_filepair *pair2,
101                                               const char *branch1,
102                                               const char *branch2,
103                                               struct stage_data *dst_entry1,
104                                               struct stage_data *dst_entry2,
105                                               struct merge_options *o,
106                                               struct stage_data *src_entry1,
107                                               struct stage_data *src_entry2)
108 {
109         struct rename_conflict_info *ci = xcalloc(1, sizeof(struct rename_conflict_info));
110         ci->rename_type = rename_type;
111         ci->pair1 = pair1;
112         ci->branch1 = branch1;
113         ci->branch2 = branch2;
114
115         ci->dst_entry1 = dst_entry1;
116         dst_entry1->rename_conflict_info = ci;
117         dst_entry1->processed = 0;
118
119         assert(!pair2 == !dst_entry2);
120         if (dst_entry2) {
121                 ci->dst_entry2 = dst_entry2;
122                 ci->pair2 = pair2;
123                 dst_entry2->rename_conflict_info = ci;
124         }
125
126         if (rename_type == RENAME_TWO_FILES_TO_ONE) {
127                 /*
128                  * For each rename, there could have been
129                  * modifications on the side of history where that
130                  * file was not renamed.
131                  */
132                 int ostage1 = o->branch1 == branch1 ? 3 : 2;
133                 int ostage2 = ostage1 ^ 1;
134
135                 ci->ren1_other.path = pair1->one->path;
136                 hashcpy(ci->ren1_other.sha1, src_entry1->stages[ostage1].sha);
137                 ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
138
139                 ci->ren2_other.path = pair2->one->path;
140                 hashcpy(ci->ren2_other.sha1, src_entry2->stages[ostage2].sha);
141                 ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
142         }
143 }
144
145 static int show(struct merge_options *o, int v)
146 {
147         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
148 }
149
150 static void flush_output(struct merge_options *o)
151 {
152         if (o->obuf.len) {
153                 fputs(o->obuf.buf, stdout);
154                 strbuf_reset(&o->obuf);
155         }
156 }
157
158 __attribute__((format (printf, 3, 4)))
159 static void output(struct merge_options *o, int v, const char *fmt, ...)
160 {
161         va_list ap;
162
163         if (!show(o, v))
164                 return;
165
166         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
167         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
168         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
169
170         va_start(ap, fmt);
171         strbuf_vaddf(&o->obuf, fmt, ap);
172         va_end(ap);
173
174         strbuf_addch(&o->obuf, '\n');
175         if (!o->buffer_output)
176                 flush_output(o);
177 }
178
179 static void output_commit_title(struct merge_options *o, struct commit *commit)
180 {
181         int i;
182         flush_output(o);
183         for (i = o->call_depth; i--;)
184                 fputs("  ", stdout);
185         if (commit->util)
186                 printf("virtual %s\n", merge_remote_util(commit)->name);
187         else {
188                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
189                 if (parse_commit(commit) != 0)
190                         printf(_("(bad commit)\n"));
191                 else {
192                         const char *title;
193                         const char *msg = get_commit_buffer(commit, NULL);
194                         int len = find_commit_subject(msg, &title);
195                         if (len)
196                                 printf("%.*s\n", len, title);
197                         unuse_commit_buffer(commit, msg);
198                 }
199         }
200 }
201
202 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
203                 const char *path, int stage, int refresh, int options)
204 {
205         struct cache_entry *ce;
206         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage,
207                               (refresh ? (CE_MATCH_REFRESH |
208                                           CE_MATCH_IGNORE_MISSING) : 0 ));
209         if (!ce)
210                 return error(_("addinfo_cache failed for path '%s'"), path);
211         return add_cache_entry(ce, options);
212 }
213
214 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
215 {
216         parse_tree(tree);
217         init_tree_desc(desc, tree->buffer, tree->size);
218 }
219
220 static int git_merge_trees(int index_only,
221                            struct tree *common,
222                            struct tree *head,
223                            struct tree *merge)
224 {
225         int rc;
226         struct tree_desc t[3];
227         struct unpack_trees_options opts;
228
229         memset(&opts, 0, sizeof(opts));
230         if (index_only)
231                 opts.index_only = 1;
232         else
233                 opts.update = 1;
234         opts.merge = 1;
235         opts.head_idx = 2;
236         opts.fn = threeway_merge;
237         opts.src_index = &the_index;
238         opts.dst_index = &the_index;
239         setup_unpack_trees_porcelain(&opts, "merge");
240
241         init_tree_desc_from_tree(t+0, common);
242         init_tree_desc_from_tree(t+1, head);
243         init_tree_desc_from_tree(t+2, merge);
244
245         rc = unpack_trees(3, t, &opts);
246         cache_tree_free(&active_cache_tree);
247         return rc;
248 }
249
250 struct tree *write_tree_from_memory(struct merge_options *o)
251 {
252         struct tree *result = NULL;
253
254         if (unmerged_cache()) {
255                 int i;
256                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
257                 for (i = 0; i < active_nr; i++) {
258                         const struct cache_entry *ce = active_cache[i];
259                         if (ce_stage(ce))
260                                 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
261                                         (int)ce_namelen(ce), ce->name);
262                 }
263                 die("Bug in merge-recursive.c");
264         }
265
266         if (!active_cache_tree)
267                 active_cache_tree = cache_tree();
268
269         if (!cache_tree_fully_valid(active_cache_tree) &&
270             cache_tree_update(&the_index, 0) < 0)
271                 die(_("error building trees"));
272
273         result = lookup_tree(active_cache_tree->sha1);
274
275         return result;
276 }
277
278 static int save_files_dirs(const unsigned char *sha1,
279                 const char *base, int baselen, const char *path,
280                 unsigned int mode, int stage, void *context)
281 {
282         int len = strlen(path);
283         char *newpath = xmalloc(baselen + len + 1);
284         struct merge_options *o = context;
285
286         memcpy(newpath, base, baselen);
287         memcpy(newpath + baselen, path, len);
288         newpath[baselen + len] = '\0';
289
290         if (S_ISDIR(mode))
291                 string_list_insert(&o->current_directory_set, newpath);
292         else
293                 string_list_insert(&o->current_file_set, newpath);
294         free(newpath);
295
296         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
297 }
298
299 static int get_files_dirs(struct merge_options *o, struct tree *tree)
300 {
301         int n;
302         struct pathspec match_all;
303         memset(&match_all, 0, sizeof(match_all));
304         if (read_tree_recursive(tree, "", 0, 0, &match_all, save_files_dirs, o))
305                 return 0;
306         n = o->current_file_set.nr + o->current_directory_set.nr;
307         return n;
308 }
309
310 /*
311  * Returns an index_entry instance which doesn't have to correspond to
312  * a real cache entry in Git's index.
313  */
314 static struct stage_data *insert_stage_data(const char *path,
315                 struct tree *o, struct tree *a, struct tree *b,
316                 struct string_list *entries)
317 {
318         struct string_list_item *item;
319         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
320         get_tree_entry(o->object.sha1, path,
321                         e->stages[1].sha, &e->stages[1].mode);
322         get_tree_entry(a->object.sha1, path,
323                         e->stages[2].sha, &e->stages[2].mode);
324         get_tree_entry(b->object.sha1, path,
325                         e->stages[3].sha, &e->stages[3].mode);
326         item = string_list_insert(entries, path);
327         item->util = e;
328         return e;
329 }
330
331 /*
332  * Create a dictionary mapping file names to stage_data objects. The
333  * dictionary contains one entry for every path with a non-zero stage entry.
334  */
335 static struct string_list *get_unmerged(void)
336 {
337         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
338         int i;
339
340         unmerged->strdup_strings = 1;
341
342         for (i = 0; i < active_nr; i++) {
343                 struct string_list_item *item;
344                 struct stage_data *e;
345                 const struct cache_entry *ce = active_cache[i];
346                 if (!ce_stage(ce))
347                         continue;
348
349                 item = string_list_lookup(unmerged, ce->name);
350                 if (!item) {
351                         item = string_list_insert(unmerged, ce->name);
352                         item->util = xcalloc(1, sizeof(struct stage_data));
353                 }
354                 e = item->util;
355                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
356                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
357         }
358
359         return unmerged;
360 }
361
362 static int string_list_df_name_compare(const void *a, const void *b)
363 {
364         const struct string_list_item *one = a;
365         const struct string_list_item *two = b;
366         int onelen = strlen(one->string);
367         int twolen = strlen(two->string);
368         /*
369          * Here we only care that entries for D/F conflicts are
370          * adjacent, in particular with the file of the D/F conflict
371          * appearing before files below the corresponding directory.
372          * The order of the rest of the list is irrelevant for us.
373          *
374          * To achieve this, we sort with df_name_compare and provide
375          * the mode S_IFDIR so that D/F conflicts will sort correctly.
376          * We use the mode S_IFDIR for everything else for simplicity,
377          * since in other cases any changes in their order due to
378          * sorting cause no problems for us.
379          */
380         int cmp = df_name_compare(one->string, onelen, S_IFDIR,
381                                   two->string, twolen, S_IFDIR);
382         /*
383          * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
384          * that 'foo' comes before 'foo/bar'.
385          */
386         if (cmp)
387                 return cmp;
388         return onelen - twolen;
389 }
390
391 static void record_df_conflict_files(struct merge_options *o,
392                                      struct string_list *entries)
393 {
394         /* If there is a D/F conflict and the file for such a conflict
395          * currently exist in the working tree, we want to allow it to be
396          * removed to make room for the corresponding directory if needed.
397          * The files underneath the directories of such D/F conflicts will
398          * be processed before the corresponding file involved in the D/F
399          * conflict.  If the D/F directory ends up being removed by the
400          * merge, then we won't have to touch the D/F file.  If the D/F
401          * directory needs to be written to the working copy, then the D/F
402          * file will simply be removed (in make_room_for_path()) to make
403          * room for the necessary paths.  Note that if both the directory
404          * and the file need to be present, then the D/F file will be
405          * reinstated with a new unique name at the time it is processed.
406          */
407         struct string_list df_sorted_entries;
408         const char *last_file = NULL;
409         int last_len = 0;
410         int i;
411
412         /*
413          * If we're merging merge-bases, we don't want to bother with
414          * any working directory changes.
415          */
416         if (o->call_depth)
417                 return;
418
419         /* Ensure D/F conflicts are adjacent in the entries list. */
420         memset(&df_sorted_entries, 0, sizeof(struct string_list));
421         for (i = 0; i < entries->nr; i++) {
422                 struct string_list_item *next = &entries->items[i];
423                 string_list_append(&df_sorted_entries, next->string)->util =
424                                    next->util;
425         }
426         qsort(df_sorted_entries.items, entries->nr, sizeof(*entries->items),
427               string_list_df_name_compare);
428
429         string_list_clear(&o->df_conflict_file_set, 1);
430         for (i = 0; i < df_sorted_entries.nr; i++) {
431                 const char *path = df_sorted_entries.items[i].string;
432                 int len = strlen(path);
433                 struct stage_data *e = df_sorted_entries.items[i].util;
434
435                 /*
436                  * Check if last_file & path correspond to a D/F conflict;
437                  * i.e. whether path is last_file+'/'+<something>.
438                  * If so, record that it's okay to remove last_file to make
439                  * room for path and friends if needed.
440                  */
441                 if (last_file &&
442                     len > last_len &&
443                     memcmp(path, last_file, last_len) == 0 &&
444                     path[last_len] == '/') {
445                         string_list_insert(&o->df_conflict_file_set, last_file);
446                 }
447
448                 /*
449                  * Determine whether path could exist as a file in the
450                  * working directory as a possible D/F conflict.  This
451                  * will only occur when it exists in stage 2 as a
452                  * file.
453                  */
454                 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
455                         last_file = path;
456                         last_len = len;
457                 } else {
458                         last_file = NULL;
459                 }
460         }
461         string_list_clear(&df_sorted_entries, 0);
462 }
463
464 struct rename {
465         struct diff_filepair *pair;
466         struct stage_data *src_entry;
467         struct stage_data *dst_entry;
468         unsigned processed:1;
469 };
470
471 /*
472  * Get information of all renames which occurred between 'o_tree' and
473  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
474  * 'b_tree') to be able to associate the correct cache entries with
475  * the rename information. 'tree' is always equal to either a_tree or b_tree.
476  */
477 static struct string_list *get_renames(struct merge_options *o,
478                                        struct tree *tree,
479                                        struct tree *o_tree,
480                                        struct tree *a_tree,
481                                        struct tree *b_tree,
482                                        struct string_list *entries)
483 {
484         int i;
485         struct string_list *renames;
486         struct diff_options opts;
487
488         renames = xcalloc(1, sizeof(struct string_list));
489         diff_setup(&opts);
490         DIFF_OPT_SET(&opts, RECURSIVE);
491         DIFF_OPT_CLR(&opts, RENAME_EMPTY);
492         opts.detect_rename = DIFF_DETECT_RENAME;
493         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
494                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
495                             1000;
496         opts.rename_score = o->rename_score;
497         opts.show_rename_progress = o->show_rename_progress;
498         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
499         diff_setup_done(&opts);
500         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
501         diffcore_std(&opts);
502         if (opts.needed_rename_limit > o->needed_rename_limit)
503                 o->needed_rename_limit = opts.needed_rename_limit;
504         for (i = 0; i < diff_queued_diff.nr; ++i) {
505                 struct string_list_item *item;
506                 struct rename *re;
507                 struct diff_filepair *pair = diff_queued_diff.queue[i];
508                 if (pair->status != 'R') {
509                         diff_free_filepair(pair);
510                         continue;
511                 }
512                 re = xmalloc(sizeof(*re));
513                 re->processed = 0;
514                 re->pair = pair;
515                 item = string_list_lookup(entries, re->pair->one->path);
516                 if (!item)
517                         re->src_entry = insert_stage_data(re->pair->one->path,
518                                         o_tree, a_tree, b_tree, entries);
519                 else
520                         re->src_entry = item->util;
521
522                 item = string_list_lookup(entries, re->pair->two->path);
523                 if (!item)
524                         re->dst_entry = insert_stage_data(re->pair->two->path,
525                                         o_tree, a_tree, b_tree, entries);
526                 else
527                         re->dst_entry = item->util;
528                 item = string_list_insert(renames, pair->one->path);
529                 item->util = re;
530         }
531         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
532         diff_queued_diff.nr = 0;
533         diff_flush(&opts);
534         return renames;
535 }
536
537 static int update_stages(const char *path, const struct diff_filespec *o,
538                          const struct diff_filespec *a,
539                          const struct diff_filespec *b)
540 {
541
542         /*
543          * NOTE: It is usually a bad idea to call update_stages on a path
544          * before calling update_file on that same path, since it can
545          * sometimes lead to spurious "refusing to lose untracked file..."
546          * messages from update_file (via make_room_for path via
547          * would_lose_untracked).  Instead, reverse the order of the calls
548          * (executing update_file first and then update_stages).
549          */
550         int clear = 1;
551         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
552         if (clear)
553                 if (remove_file_from_cache(path))
554                         return -1;
555         if (o)
556                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
557                         return -1;
558         if (a)
559                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
560                         return -1;
561         if (b)
562                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
563                         return -1;
564         return 0;
565 }
566
567 static void update_entry(struct stage_data *entry,
568                          struct diff_filespec *o,
569                          struct diff_filespec *a,
570                          struct diff_filespec *b)
571 {
572         entry->processed = 0;
573         entry->stages[1].mode = o->mode;
574         entry->stages[2].mode = a->mode;
575         entry->stages[3].mode = b->mode;
576         hashcpy(entry->stages[1].sha, o->sha1);
577         hashcpy(entry->stages[2].sha, a->sha1);
578         hashcpy(entry->stages[3].sha, b->sha1);
579 }
580
581 static int remove_file(struct merge_options *o, int clean,
582                        const char *path, int no_wd)
583 {
584         int update_cache = o->call_depth || clean;
585         int update_working_directory = !o->call_depth && !no_wd;
586
587         if (update_cache) {
588                 if (remove_file_from_cache(path))
589                         return -1;
590         }
591         if (update_working_directory) {
592                 if (ignore_case) {
593                         struct cache_entry *ce;
594                         ce = cache_file_exists(path, strlen(path), ignore_case);
595                         if (ce && ce_stage(ce) == 0)
596                                 return 0;
597                 }
598                 if (remove_path(path))
599                         return -1;
600         }
601         return 0;
602 }
603
604 /* add a string to a strbuf, but converting "/" to "_" */
605 static void add_flattened_path(struct strbuf *out, const char *s)
606 {
607         size_t i = out->len;
608         strbuf_addstr(out, s);
609         for (; i < out->len; i++)
610                 if (out->buf[i] == '/')
611                         out->buf[i] = '_';
612 }
613
614 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
615 {
616         struct strbuf newpath = STRBUF_INIT;
617         int suffix = 0;
618         struct stat st;
619         size_t base_len;
620
621         strbuf_addf(&newpath, "%s~", path);
622         add_flattened_path(&newpath, branch);
623
624         base_len = newpath.len;
625         while (string_list_has_string(&o->current_file_set, newpath.buf) ||
626                string_list_has_string(&o->current_directory_set, newpath.buf) ||
627                lstat(newpath.buf, &st) == 0) {
628                 strbuf_setlen(&newpath, base_len);
629                 strbuf_addf(&newpath, "_%d", suffix++);
630         }
631
632         string_list_insert(&o->current_file_set, newpath.buf);
633         return strbuf_detach(&newpath, NULL);
634 }
635
636 static int dir_in_way(const char *path, int check_working_copy)
637 {
638         int pos, pathlen = strlen(path);
639         char *dirpath = xmalloc(pathlen + 2);
640         struct stat st;
641
642         strcpy(dirpath, path);
643         dirpath[pathlen] = '/';
644         dirpath[pathlen+1] = '\0';
645
646         pos = cache_name_pos(dirpath, pathlen+1);
647
648         if (pos < 0)
649                 pos = -1 - pos;
650         if (pos < active_nr &&
651             !strncmp(dirpath, active_cache[pos]->name, pathlen+1)) {
652                 free(dirpath);
653                 return 1;
654         }
655
656         free(dirpath);
657         return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
658 }
659
660 static int was_tracked(const char *path)
661 {
662         int pos = cache_name_pos(path, strlen(path));
663
664         if (pos < 0)
665                 pos = -1 - pos;
666         while (pos < active_nr &&
667                !strcmp(path, active_cache[pos]->name)) {
668                 /*
669                  * If stage #0, it is definitely tracked.
670                  * If it has stage #2 then it was tracked
671                  * before this merge started.  All other
672                  * cases the path was not tracked.
673                  */
674                 switch (ce_stage(active_cache[pos])) {
675                 case 0:
676                 case 2:
677                         return 1;
678                 }
679                 pos++;
680         }
681         return 0;
682 }
683
684 static int would_lose_untracked(const char *path)
685 {
686         return !was_tracked(path) && file_exists(path);
687 }
688
689 static int make_room_for_path(struct merge_options *o, const char *path)
690 {
691         int status, i;
692         const char *msg = _("failed to create path '%s'%s");
693
694         /* Unlink any D/F conflict files that are in the way */
695         for (i = 0; i < o->df_conflict_file_set.nr; i++) {
696                 const char *df_path = o->df_conflict_file_set.items[i].string;
697                 size_t pathlen = strlen(path);
698                 size_t df_pathlen = strlen(df_path);
699                 if (df_pathlen < pathlen &&
700                     path[df_pathlen] == '/' &&
701                     strncmp(path, df_path, df_pathlen) == 0) {
702                         output(o, 3,
703                                _("Removing %s to make room for subdirectory\n"),
704                                df_path);
705                         unlink(df_path);
706                         unsorted_string_list_delete_item(&o->df_conflict_file_set,
707                                                          i, 0);
708                         break;
709                 }
710         }
711
712         /* Make sure leading directories are created */
713         status = safe_create_leading_directories_const(path);
714         if (status) {
715                 if (status == SCLD_EXISTS) {
716                         /* something else exists */
717                         error(msg, path, _(": perhaps a D/F conflict?"));
718                         return -1;
719                 }
720                 die(msg, path, "");
721         }
722
723         /*
724          * Do not unlink a file in the work tree if we are not
725          * tracking it.
726          */
727         if (would_lose_untracked(path))
728                 return error(_("refusing to lose untracked file at '%s'"),
729                              path);
730
731         /* Successful unlink is good.. */
732         if (!unlink(path))
733                 return 0;
734         /* .. and so is no existing file */
735         if (errno == ENOENT)
736                 return 0;
737         /* .. but not some other error (who really cares what?) */
738         return error(msg, path, _(": perhaps a D/F conflict?"));
739 }
740
741 static void update_file_flags(struct merge_options *o,
742                               const unsigned char *sha,
743                               unsigned mode,
744                               const char *path,
745                               int update_cache,
746                               int update_wd)
747 {
748         if (o->call_depth)
749                 update_wd = 0;
750
751         if (update_wd) {
752                 enum object_type type;
753                 void *buf;
754                 unsigned long size;
755
756                 if (S_ISGITLINK(mode)) {
757                         /*
758                          * We may later decide to recursively descend into
759                          * the submodule directory and update its index
760                          * and/or work tree, but we do not do that now.
761                          */
762                         update_wd = 0;
763                         goto update_index;
764                 }
765
766                 buf = read_sha1_file(sha, &type, &size);
767                 if (!buf)
768                         die(_("cannot read object %s '%s'"), sha1_to_hex(sha), path);
769                 if (type != OBJ_BLOB)
770                         die(_("blob expected for %s '%s'"), sha1_to_hex(sha), path);
771                 if (S_ISREG(mode)) {
772                         struct strbuf strbuf = STRBUF_INIT;
773                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
774                                 free(buf);
775                                 size = strbuf.len;
776                                 buf = strbuf_detach(&strbuf, NULL);
777                         }
778                 }
779
780                 if (make_room_for_path(o, path) < 0) {
781                         update_wd = 0;
782                         free(buf);
783                         goto update_index;
784                 }
785                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
786                         int fd;
787                         if (mode & 0100)
788                                 mode = 0777;
789                         else
790                                 mode = 0666;
791                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
792                         if (fd < 0)
793                                 die_errno(_("failed to open '%s'"), path);
794                         write_in_full(fd, buf, size);
795                         close(fd);
796                 } else if (S_ISLNK(mode)) {
797                         char *lnk = xmemdupz(buf, size);
798                         safe_create_leading_directories_const(path);
799                         unlink(path);
800                         if (symlink(lnk, path))
801                                 die_errno(_("failed to symlink '%s'"), path);
802                         free(lnk);
803                 } else
804                         die(_("do not know what to do with %06o %s '%s'"),
805                             mode, sha1_to_hex(sha), path);
806                 free(buf);
807         }
808  update_index:
809         if (update_cache)
810                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
811 }
812
813 static void update_file(struct merge_options *o,
814                         int clean,
815                         const unsigned char *sha,
816                         unsigned mode,
817                         const char *path)
818 {
819         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
820 }
821
822 /* Low level file merging, update and removal */
823
824 struct merge_file_info {
825         unsigned char sha[20];
826         unsigned mode;
827         unsigned clean:1,
828                  merge:1;
829 };
830
831 static int merge_3way(struct merge_options *o,
832                       mmbuffer_t *result_buf,
833                       const struct diff_filespec *one,
834                       const struct diff_filespec *a,
835                       const struct diff_filespec *b,
836                       const char *branch1,
837                       const char *branch2)
838 {
839         mmfile_t orig, src1, src2;
840         struct ll_merge_options ll_opts = {0};
841         char *base_name, *name1, *name2;
842         int merge_status;
843
844         ll_opts.renormalize = o->renormalize;
845         ll_opts.xdl_opts = o->xdl_opts;
846
847         if (o->call_depth) {
848                 ll_opts.virtual_ancestor = 1;
849                 ll_opts.variant = 0;
850         } else {
851                 switch (o->recursive_variant) {
852                 case MERGE_RECURSIVE_OURS:
853                         ll_opts.variant = XDL_MERGE_FAVOR_OURS;
854                         break;
855                 case MERGE_RECURSIVE_THEIRS:
856                         ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
857                         break;
858                 default:
859                         ll_opts.variant = 0;
860                         break;
861                 }
862         }
863
864         if (strcmp(a->path, b->path) ||
865             (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
866                 base_name = o->ancestor == NULL ? NULL :
867                         mkpathdup("%s:%s", o->ancestor, one->path);
868                 name1 = mkpathdup("%s:%s", branch1, a->path);
869                 name2 = mkpathdup("%s:%s", branch2, b->path);
870         } else {
871                 base_name = o->ancestor == NULL ? NULL :
872                         mkpathdup("%s", o->ancestor);
873                 name1 = mkpathdup("%s", branch1);
874                 name2 = mkpathdup("%s", branch2);
875         }
876
877         read_mmblob(&orig, one->sha1);
878         read_mmblob(&src1, a->sha1);
879         read_mmblob(&src2, b->sha1);
880
881         merge_status = ll_merge(result_buf, a->path, &orig, base_name,
882                                 &src1, name1, &src2, name2, &ll_opts);
883
884         free(base_name);
885         free(name1);
886         free(name2);
887         free(orig.ptr);
888         free(src1.ptr);
889         free(src2.ptr);
890         return merge_status;
891 }
892
893 static struct merge_file_info merge_file_1(struct merge_options *o,
894                                            const struct diff_filespec *one,
895                                            const struct diff_filespec *a,
896                                            const struct diff_filespec *b,
897                                            const char *branch1,
898                                            const char *branch2)
899 {
900         struct merge_file_info result;
901         result.merge = 0;
902         result.clean = 1;
903
904         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
905                 result.clean = 0;
906                 if (S_ISREG(a->mode)) {
907                         result.mode = a->mode;
908                         hashcpy(result.sha, a->sha1);
909                 } else {
910                         result.mode = b->mode;
911                         hashcpy(result.sha, b->sha1);
912                 }
913         } else {
914                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
915                         result.merge = 1;
916
917                 /*
918                  * Merge modes
919                  */
920                 if (a->mode == b->mode || a->mode == one->mode)
921                         result.mode = b->mode;
922                 else {
923                         result.mode = a->mode;
924                         if (b->mode != one->mode) {
925                                 result.clean = 0;
926                                 result.merge = 1;
927                         }
928                 }
929
930                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
931                         hashcpy(result.sha, b->sha1);
932                 else if (sha_eq(b->sha1, one->sha1))
933                         hashcpy(result.sha, a->sha1);
934                 else if (S_ISREG(a->mode)) {
935                         mmbuffer_t result_buf;
936                         int merge_status;
937
938                         merge_status = merge_3way(o, &result_buf, one, a, b,
939                                                   branch1, branch2);
940
941                         if ((merge_status < 0) || !result_buf.ptr)
942                                 die(_("Failed to execute internal merge"));
943
944                         if (write_sha1_file(result_buf.ptr, result_buf.size,
945                                             blob_type, result.sha))
946                                 die(_("Unable to add %s to database"),
947                                     a->path);
948
949                         free(result_buf.ptr);
950                         result.clean = (merge_status == 0);
951                 } else if (S_ISGITLINK(a->mode)) {
952                         result.clean = merge_submodule(result.sha,
953                                                        one->path, one->sha1,
954                                                        a->sha1, b->sha1,
955                                                        !o->call_depth);
956                 } else if (S_ISLNK(a->mode)) {
957                         hashcpy(result.sha, a->sha1);
958
959                         if (!sha_eq(a->sha1, b->sha1))
960                                 result.clean = 0;
961                 } else {
962                         die(_("unsupported object type in the tree"));
963                 }
964         }
965
966         return result;
967 }
968
969 static struct merge_file_info
970 merge_file_special_markers(struct merge_options *o,
971                            const struct diff_filespec *one,
972                            const struct diff_filespec *a,
973                            const struct diff_filespec *b,
974                            const char *branch1,
975                            const char *filename1,
976                            const char *branch2,
977                            const char *filename2)
978 {
979         char *side1 = NULL;
980         char *side2 = NULL;
981         struct merge_file_info mfi;
982
983         if (filename1)
984                 side1 = xstrfmt("%s:%s", branch1, filename1);
985         if (filename2)
986                 side2 = xstrfmt("%s:%s", branch2, filename2);
987
988         mfi = merge_file_1(o, one, a, b,
989                            side1 ? side1 : branch1, side2 ? side2 : branch2);
990         free(side1);
991         free(side2);
992         return mfi;
993 }
994
995 static struct merge_file_info merge_file_one(struct merge_options *o,
996                                          const char *path,
997                                          const unsigned char *o_sha, int o_mode,
998                                          const unsigned char *a_sha, int a_mode,
999                                          const unsigned char *b_sha, int b_mode,
1000                                          const char *branch1,
1001                                          const char *branch2)
1002 {
1003         struct diff_filespec one, a, b;
1004
1005         one.path = a.path = b.path = (char *)path;
1006         hashcpy(one.sha1, o_sha);
1007         one.mode = o_mode;
1008         hashcpy(a.sha1, a_sha);
1009         a.mode = a_mode;
1010         hashcpy(b.sha1, b_sha);
1011         b.mode = b_mode;
1012         return merge_file_1(o, &one, &a, &b, branch1, branch2);
1013 }
1014
1015 static void handle_change_delete(struct merge_options *o,
1016                                  const char *path,
1017                                  const unsigned char *o_sha, int o_mode,
1018                                  const unsigned char *a_sha, int a_mode,
1019                                  const unsigned char *b_sha, int b_mode,
1020                                  const char *change, const char *change_past)
1021 {
1022         char *renamed = NULL;
1023         if (dir_in_way(path, !o->call_depth)) {
1024                 renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1025         }
1026
1027         if (o->call_depth) {
1028                 /*
1029                  * We cannot arbitrarily accept either a_sha or b_sha as
1030                  * correct; since there is no true "middle point" between
1031                  * them, simply reuse the base version for virtual merge base.
1032                  */
1033                 remove_file_from_cache(path);
1034                 update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
1035         } else if (!a_sha) {
1036                 if (!renamed) {
1037                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1038                                "and %s in %s. Version %s of %s left in tree."),
1039                                change, path, o->branch1, change_past,
1040                                o->branch2, o->branch2, path);
1041                         update_file(o, 0, b_sha, b_mode, path);
1042                 } else {
1043                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1044                                "and %s in %s. Version %s of %s left in tree at %s."),
1045                                change, path, o->branch1, change_past,
1046                                o->branch2, o->branch2, path, renamed);
1047                         update_file(o, 0, b_sha, b_mode, renamed);
1048                 }
1049         } else {
1050                 if (!renamed) {
1051                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1052                                "and %s in %s. Version %s of %s left in tree."),
1053                                change, path, o->branch2, change_past,
1054                                o->branch1, o->branch1, path);
1055                 } else {
1056                         output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
1057                                "and %s in %s. Version %s of %s left in tree at %s."),
1058                                change, path, o->branch2, change_past,
1059                                o->branch1, o->branch1, path, renamed);
1060                         update_file(o, 0, a_sha, a_mode, renamed);
1061                 }
1062                 /*
1063                  * No need to call update_file() on path when !renamed, since
1064                  * that would needlessly touch path.  We could call
1065                  * update_file_flags() with update_cache=0 and update_wd=0,
1066                  * but that's a no-op.
1067                  */
1068         }
1069         free(renamed);
1070 }
1071
1072 static void conflict_rename_delete(struct merge_options *o,
1073                                    struct diff_filepair *pair,
1074                                    const char *rename_branch,
1075                                    const char *other_branch)
1076 {
1077         const struct diff_filespec *orig = pair->one;
1078         const struct diff_filespec *dest = pair->two;
1079         const unsigned char *a_sha = NULL;
1080         const unsigned char *b_sha = NULL;
1081         int a_mode = 0;
1082         int b_mode = 0;
1083
1084         if (rename_branch == o->branch1) {
1085                 a_sha = dest->sha1;
1086                 a_mode = dest->mode;
1087         } else {
1088                 b_sha = dest->sha1;
1089                 b_mode = dest->mode;
1090         }
1091
1092         handle_change_delete(o,
1093                              o->call_depth ? orig->path : dest->path,
1094                              orig->sha1, orig->mode,
1095                              a_sha, a_mode,
1096                              b_sha, b_mode,
1097                              _("rename"), _("renamed"));
1098
1099         if (o->call_depth) {
1100                 remove_file_from_cache(dest->path);
1101         } else {
1102                 update_stages(dest->path, NULL,
1103                               rename_branch == o->branch1 ? dest : NULL,
1104                               rename_branch == o->branch1 ? NULL : dest);
1105         }
1106
1107 }
1108
1109 static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
1110                                                  struct stage_data *entry,
1111                                                  int stage)
1112 {
1113         unsigned char *sha = entry->stages[stage].sha;
1114         unsigned mode = entry->stages[stage].mode;
1115         if (mode == 0 || is_null_sha1(sha))
1116                 return NULL;
1117         hashcpy(target->sha1, sha);
1118         target->mode = mode;
1119         return target;
1120 }
1121
1122 static void handle_file(struct merge_options *o,
1123                         struct diff_filespec *rename,
1124                         int stage,
1125                         struct rename_conflict_info *ci)
1126 {
1127         char *dst_name = rename->path;
1128         struct stage_data *dst_entry;
1129         const char *cur_branch, *other_branch;
1130         struct diff_filespec other;
1131         struct diff_filespec *add;
1132
1133         if (stage == 2) {
1134                 dst_entry = ci->dst_entry1;
1135                 cur_branch = ci->branch1;
1136                 other_branch = ci->branch2;
1137         } else {
1138                 dst_entry = ci->dst_entry2;
1139                 cur_branch = ci->branch2;
1140                 other_branch = ci->branch1;
1141         }
1142
1143         add = filespec_from_entry(&other, dst_entry, stage ^ 1);
1144         if (add) {
1145                 char *add_name = unique_path(o, rename->path, other_branch);
1146                 update_file(o, 0, add->sha1, add->mode, add_name);
1147
1148                 remove_file(o, 0, rename->path, 0);
1149                 dst_name = unique_path(o, rename->path, cur_branch);
1150         } else {
1151                 if (dir_in_way(rename->path, !o->call_depth)) {
1152                         dst_name = unique_path(o, rename->path, cur_branch);
1153                         output(o, 1, _("%s is a directory in %s adding as %s instead"),
1154                                rename->path, other_branch, dst_name);
1155                 }
1156         }
1157         update_file(o, 0, rename->sha1, rename->mode, dst_name);
1158         if (stage == 2)
1159                 update_stages(rename->path, NULL, rename, add);
1160         else
1161                 update_stages(rename->path, NULL, add, rename);
1162
1163         if (dst_name != rename->path)
1164                 free(dst_name);
1165 }
1166
1167 static void conflict_rename_rename_1to2(struct merge_options *o,
1168                                         struct rename_conflict_info *ci)
1169 {
1170         /* One file was renamed in both branches, but to different names. */
1171         struct diff_filespec *one = ci->pair1->one;
1172         struct diff_filespec *a = ci->pair1->two;
1173         struct diff_filespec *b = ci->pair2->two;
1174
1175         output(o, 1, _("CONFLICT (rename/rename): "
1176                "Rename \"%s\"->\"%s\" in branch \"%s\" "
1177                "rename \"%s\"->\"%s\" in \"%s\"%s"),
1178                one->path, a->path, ci->branch1,
1179                one->path, b->path, ci->branch2,
1180                o->call_depth ? _(" (left unresolved)") : "");
1181         if (o->call_depth) {
1182                 struct merge_file_info mfi;
1183                 struct diff_filespec other;
1184                 struct diff_filespec *add;
1185                 mfi = merge_file_one(o, one->path,
1186                                  one->sha1, one->mode,
1187                                  a->sha1, a->mode,
1188                                  b->sha1, b->mode,
1189                                  ci->branch1, ci->branch2);
1190                 /*
1191                  * FIXME: For rename/add-source conflicts (if we could detect
1192                  * such), this is wrong.  We should instead find a unique
1193                  * pathname and then either rename the add-source file to that
1194                  * unique path, or use that unique path instead of src here.
1195                  */
1196                 update_file(o, 0, mfi.sha, mfi.mode, one->path);
1197
1198                 /*
1199                  * Above, we put the merged content at the merge-base's
1200                  * path.  Now we usually need to delete both a->path and
1201                  * b->path.  However, the rename on each side of the merge
1202                  * could also be involved in a rename/add conflict.  In
1203                  * such cases, we should keep the added file around,
1204                  * resolving the conflict at that path in its favor.
1205                  */
1206                 add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
1207                 if (add)
1208                         update_file(o, 0, add->sha1, add->mode, a->path);
1209                 else
1210                         remove_file_from_cache(a->path);
1211                 add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
1212                 if (add)
1213                         update_file(o, 0, add->sha1, add->mode, b->path);
1214                 else
1215                         remove_file_from_cache(b->path);
1216         } else {
1217                 handle_file(o, a, 2, ci);
1218                 handle_file(o, b, 3, ci);
1219         }
1220 }
1221
1222 static void conflict_rename_rename_2to1(struct merge_options *o,
1223                                         struct rename_conflict_info *ci)
1224 {
1225         /* Two files, a & b, were renamed to the same thing, c. */
1226         struct diff_filespec *a = ci->pair1->one;
1227         struct diff_filespec *b = ci->pair2->one;
1228         struct diff_filespec *c1 = ci->pair1->two;
1229         struct diff_filespec *c2 = ci->pair2->two;
1230         char *path = c1->path; /* == c2->path */
1231         struct merge_file_info mfi_c1;
1232         struct merge_file_info mfi_c2;
1233
1234         output(o, 1, _("CONFLICT (rename/rename): "
1235                "Rename %s->%s in %s. "
1236                "Rename %s->%s in %s"),
1237                a->path, c1->path, ci->branch1,
1238                b->path, c2->path, ci->branch2);
1239
1240         remove_file(o, 1, a->path, would_lose_untracked(a->path));
1241         remove_file(o, 1, b->path, would_lose_untracked(b->path));
1242
1243         mfi_c1 = merge_file_special_markers(o, a, c1, &ci->ren1_other,
1244                                             o->branch1, c1->path,
1245                                             o->branch2, ci->ren1_other.path);
1246         mfi_c2 = merge_file_special_markers(o, b, &ci->ren2_other, c2,
1247                                             o->branch1, ci->ren2_other.path,
1248                                             o->branch2, c2->path);
1249
1250         if (o->call_depth) {
1251                 /*
1252                  * If mfi_c1.clean && mfi_c2.clean, then it might make
1253                  * sense to do a two-way merge of those results.  But, I
1254                  * think in all cases, it makes sense to have the virtual
1255                  * merge base just undo the renames; they can be detected
1256                  * again later for the non-recursive merge.
1257                  */
1258                 remove_file(o, 0, path, 0);
1259                 update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
1260                 update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
1261         } else {
1262                 char *new_path1 = unique_path(o, path, ci->branch1);
1263                 char *new_path2 = unique_path(o, path, ci->branch2);
1264                 output(o, 1, _("Renaming %s to %s and %s to %s instead"),
1265                        a->path, new_path1, b->path, new_path2);
1266                 remove_file(o, 0, path, 0);
1267                 update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
1268                 update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
1269                 free(new_path2);
1270                 free(new_path1);
1271         }
1272 }
1273
1274 static int process_renames(struct merge_options *o,
1275                            struct string_list *a_renames,
1276                            struct string_list *b_renames)
1277 {
1278         int clean_merge = 1, i, j;
1279         struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
1280         struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
1281         const struct rename *sre;
1282
1283         for (i = 0; i < a_renames->nr; i++) {
1284                 sre = a_renames->items[i].util;
1285                 string_list_insert(&a_by_dst, sre->pair->two->path)->util
1286                         = (void *)sre;
1287         }
1288         for (i = 0; i < b_renames->nr; i++) {
1289                 sre = b_renames->items[i].util;
1290                 string_list_insert(&b_by_dst, sre->pair->two->path)->util
1291                         = (void *)sre;
1292         }
1293
1294         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1295                 struct string_list *renames1, *renames2Dst;
1296                 struct rename *ren1 = NULL, *ren2 = NULL;
1297                 const char *branch1, *branch2;
1298                 const char *ren1_src, *ren1_dst;
1299                 struct string_list_item *lookup;
1300
1301                 if (i >= a_renames->nr) {
1302                         ren2 = b_renames->items[j++].util;
1303                 } else if (j >= b_renames->nr) {
1304                         ren1 = a_renames->items[i++].util;
1305                 } else {
1306                         int compare = strcmp(a_renames->items[i].string,
1307                                              b_renames->items[j].string);
1308                         if (compare <= 0)
1309                                 ren1 = a_renames->items[i++].util;
1310                         if (compare >= 0)
1311                                 ren2 = b_renames->items[j++].util;
1312                 }
1313
1314                 /* TODO: refactor, so that 1/2 are not needed */
1315                 if (ren1) {
1316                         renames1 = a_renames;
1317                         renames2Dst = &b_by_dst;
1318                         branch1 = o->branch1;
1319                         branch2 = o->branch2;
1320                 } else {
1321                         struct rename *tmp;
1322                         renames1 = b_renames;
1323                         renames2Dst = &a_by_dst;
1324                         branch1 = o->branch2;
1325                         branch2 = o->branch1;
1326                         tmp = ren2;
1327                         ren2 = ren1;
1328                         ren1 = tmp;
1329                 }
1330
1331                 if (ren1->processed)
1332                         continue;
1333                 ren1->processed = 1;
1334                 ren1->dst_entry->processed = 1;
1335                 /* BUG: We should only mark src_entry as processed if we
1336                  * are not dealing with a rename + add-source case.
1337                  */
1338                 ren1->src_entry->processed = 1;
1339
1340                 ren1_src = ren1->pair->one->path;
1341                 ren1_dst = ren1->pair->two->path;
1342
1343                 if (ren2) {
1344                         /* One file renamed on both sides */
1345                         const char *ren2_src = ren2->pair->one->path;
1346                         const char *ren2_dst = ren2->pair->two->path;
1347                         enum rename_type rename_type;
1348                         if (strcmp(ren1_src, ren2_src) != 0)
1349                                 die("ren1_src != ren2_src");
1350                         ren2->dst_entry->processed = 1;
1351                         ren2->processed = 1;
1352                         if (strcmp(ren1_dst, ren2_dst) != 0) {
1353                                 rename_type = RENAME_ONE_FILE_TO_TWO;
1354                                 clean_merge = 0;
1355                         } else {
1356                                 rename_type = RENAME_ONE_FILE_TO_ONE;
1357                                 /* BUG: We should only remove ren1_src in
1358                                  * the base stage (think of rename +
1359                                  * add-source cases).
1360                                  */
1361                                 remove_file(o, 1, ren1_src, 1);
1362                                 update_entry(ren1->dst_entry,
1363                                              ren1->pair->one,
1364                                              ren1->pair->two,
1365                                              ren2->pair->two);
1366                         }
1367                         setup_rename_conflict_info(rename_type,
1368                                                    ren1->pair,
1369                                                    ren2->pair,
1370                                                    branch1,
1371                                                    branch2,
1372                                                    ren1->dst_entry,
1373                                                    ren2->dst_entry,
1374                                                    o,
1375                                                    NULL,
1376                                                    NULL);
1377                 } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
1378                         /* Two different files renamed to the same thing */
1379                         char *ren2_dst;
1380                         ren2 = lookup->util;
1381                         ren2_dst = ren2->pair->two->path;
1382                         if (strcmp(ren1_dst, ren2_dst) != 0)
1383                                 die("ren1_dst != ren2_dst");
1384
1385                         clean_merge = 0;
1386                         ren2->processed = 1;
1387                         /*
1388                          * BUG: We should only mark src_entry as processed
1389                          * if we are not dealing with a rename + add-source
1390                          * case.
1391                          */
1392                         ren2->src_entry->processed = 1;
1393
1394                         setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
1395                                                    ren1->pair,
1396                                                    ren2->pair,
1397                                                    branch1,
1398                                                    branch2,
1399                                                    ren1->dst_entry,
1400                                                    ren2->dst_entry,
1401                                                    o,
1402                                                    ren1->src_entry,
1403                                                    ren2->src_entry);
1404
1405                 } else {
1406                         /* Renamed in 1, maybe changed in 2 */
1407                         /* we only use sha1 and mode of these */
1408                         struct diff_filespec src_other, dst_other;
1409                         int try_merge;
1410
1411                         /*
1412                          * unpack_trees loads entries from common-commit
1413                          * into stage 1, from head-commit into stage 2, and
1414                          * from merge-commit into stage 3.  We keep track
1415                          * of which side corresponds to the rename.
1416                          */
1417                         int renamed_stage = a_renames == renames1 ? 2 : 3;
1418                         int other_stage =   a_renames == renames1 ? 3 : 2;
1419
1420                         /* BUG: We should only remove ren1_src in the base
1421                          * stage and in other_stage (think of rename +
1422                          * add-source case).
1423                          */
1424                         remove_file(o, 1, ren1_src,
1425                                     renamed_stage == 2 || !was_tracked(ren1_src));
1426
1427                         hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1428                         src_other.mode = ren1->src_entry->stages[other_stage].mode;
1429                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1430                         dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1431                         try_merge = 0;
1432
1433                         if (sha_eq(src_other.sha1, null_sha1)) {
1434                                 setup_rename_conflict_info(RENAME_DELETE,
1435                                                            ren1->pair,
1436                                                            NULL,
1437                                                            branch1,
1438                                                            branch2,
1439                                                            ren1->dst_entry,
1440                                                            NULL,
1441                                                            o,
1442                                                            NULL,
1443                                                            NULL);
1444                         } else if ((dst_other.mode == ren1->pair->two->mode) &&
1445                                    sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1446                                 /*
1447                                  * Added file on the other side identical to
1448                                  * the file being renamed: clean merge.
1449                                  * Also, there is no need to overwrite the
1450                                  * file already in the working copy, so call
1451                                  * update_file_flags() instead of
1452                                  * update_file().
1453                                  */
1454                                 update_file_flags(o,
1455                                                   ren1->pair->two->sha1,
1456                                                   ren1->pair->two->mode,
1457                                                   ren1_dst,
1458                                                   1, /* update_cache */
1459                                                   0  /* update_wd    */);
1460                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1461                                 clean_merge = 0;
1462                                 try_merge = 1;
1463                                 output(o, 1, _("CONFLICT (rename/add): Rename %s->%s in %s. "
1464                                        "%s added in %s"),
1465                                        ren1_src, ren1_dst, branch1,
1466                                        ren1_dst, branch2);
1467                                 if (o->call_depth) {
1468                                         struct merge_file_info mfi;
1469                                         mfi = merge_file_one(o, ren1_dst, null_sha1, 0,
1470                                                          ren1->pair->two->sha1, ren1->pair->two->mode,
1471                                                          dst_other.sha1, dst_other.mode,
1472                                                          branch1, branch2);
1473                                         output(o, 1, _("Adding merged %s"), ren1_dst);
1474                                         update_file(o, 0, mfi.sha, mfi.mode, ren1_dst);
1475                                         try_merge = 0;
1476                                 } else {
1477                                         char *new_path = unique_path(o, ren1_dst, branch2);
1478                                         output(o, 1, _("Adding as %s instead"), new_path);
1479                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1480                                         free(new_path);
1481                                 }
1482                         } else
1483                                 try_merge = 1;
1484
1485                         if (try_merge) {
1486                                 struct diff_filespec *one, *a, *b;
1487                                 src_other.path = (char *)ren1_src;
1488
1489                                 one = ren1->pair->one;
1490                                 if (a_renames == renames1) {
1491                                         a = ren1->pair->two;
1492                                         b = &src_other;
1493                                 } else {
1494                                         b = ren1->pair->two;
1495                                         a = &src_other;
1496                                 }
1497                                 update_entry(ren1->dst_entry, one, a, b);
1498                                 setup_rename_conflict_info(RENAME_NORMAL,
1499                                                            ren1->pair,
1500                                                            NULL,
1501                                                            branch1,
1502                                                            NULL,
1503                                                            ren1->dst_entry,
1504                                                            NULL,
1505                                                            o,
1506                                                            NULL,
1507                                                            NULL);
1508                         }
1509                 }
1510         }
1511         string_list_clear(&a_by_dst, 0);
1512         string_list_clear(&b_by_dst, 0);
1513
1514         return clean_merge;
1515 }
1516
1517 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1518 {
1519         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1520 }
1521
1522 static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1523 {
1524         void *buf;
1525         enum object_type type;
1526         unsigned long size;
1527         buf = read_sha1_file(sha1, &type, &size);
1528         if (!buf)
1529                 return error(_("cannot read object %s"), sha1_to_hex(sha1));
1530         if (type != OBJ_BLOB) {
1531                 free(buf);
1532                 return error(_("object %s is not a blob"), sha1_to_hex(sha1));
1533         }
1534         strbuf_attach(dst, buf, size, size + 1);
1535         return 0;
1536 }
1537
1538 static int blob_unchanged(const unsigned char *o_sha,
1539                           const unsigned char *a_sha,
1540                           int renormalize, const char *path)
1541 {
1542         struct strbuf o = STRBUF_INIT;
1543         struct strbuf a = STRBUF_INIT;
1544         int ret = 0; /* assume changed for safety */
1545
1546         if (sha_eq(o_sha, a_sha))
1547                 return 1;
1548         if (!renormalize)
1549                 return 0;
1550
1551         assert(o_sha && a_sha);
1552         if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1553                 goto error_return;
1554         /*
1555          * Note: binary | is used so that both renormalizations are
1556          * performed.  Comparison can be skipped if both files are
1557          * unchanged since their sha1s have already been compared.
1558          */
1559         if (renormalize_buffer(path, o.buf, o.len, &o) |
1560             renormalize_buffer(path, a.buf, o.len, &a))
1561                 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1562
1563 error_return:
1564         strbuf_release(&o);
1565         strbuf_release(&a);
1566         return ret;
1567 }
1568
1569 static void handle_modify_delete(struct merge_options *o,
1570                                  const char *path,
1571                                  unsigned char *o_sha, int o_mode,
1572                                  unsigned char *a_sha, int a_mode,
1573                                  unsigned char *b_sha, int b_mode)
1574 {
1575         handle_change_delete(o,
1576                              path,
1577                              o_sha, o_mode,
1578                              a_sha, a_mode,
1579                              b_sha, b_mode,
1580                              _("modify"), _("modified"));
1581 }
1582
1583 static int merge_content(struct merge_options *o,
1584                          const char *path,
1585                          unsigned char *o_sha, int o_mode,
1586                          unsigned char *a_sha, int a_mode,
1587                          unsigned char *b_sha, int b_mode,
1588                          struct rename_conflict_info *rename_conflict_info)
1589 {
1590         const char *reason = _("content");
1591         const char *path1 = NULL, *path2 = NULL;
1592         struct merge_file_info mfi;
1593         struct diff_filespec one, a, b;
1594         unsigned df_conflict_remains = 0;
1595
1596         if (!o_sha) {
1597                 reason = _("add/add");
1598                 o_sha = (unsigned char *)null_sha1;
1599         }
1600         one.path = a.path = b.path = (char *)path;
1601         hashcpy(one.sha1, o_sha);
1602         one.mode = o_mode;
1603         hashcpy(a.sha1, a_sha);
1604         a.mode = a_mode;
1605         hashcpy(b.sha1, b_sha);
1606         b.mode = b_mode;
1607
1608         if (rename_conflict_info) {
1609                 struct diff_filepair *pair1 = rename_conflict_info->pair1;
1610
1611                 path1 = (o->branch1 == rename_conflict_info->branch1) ?
1612                         pair1->two->path : pair1->one->path;
1613                 /* If rename_conflict_info->pair2 != NULL, we are in
1614                  * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
1615                  * normal rename.
1616                  */
1617                 path2 = (rename_conflict_info->pair2 ||
1618                          o->branch2 == rename_conflict_info->branch1) ?
1619                         pair1->two->path : pair1->one->path;
1620
1621                 if (dir_in_way(path, !o->call_depth))
1622                         df_conflict_remains = 1;
1623         }
1624         mfi = merge_file_special_markers(o, &one, &a, &b,
1625                                          o->branch1, path1,
1626                                          o->branch2, path2);
1627
1628         if (mfi.clean && !df_conflict_remains &&
1629             sha_eq(mfi.sha, a_sha) && mfi.mode == a_mode) {
1630                 int path_renamed_outside_HEAD;
1631                 output(o, 3, _("Skipped %s (merged same as existing)"), path);
1632                 /*
1633                  * The content merge resulted in the same file contents we
1634                  * already had.  We can return early if those file contents
1635                  * are recorded at the correct path (which may not be true
1636                  * if the merge involves a rename).
1637                  */
1638                 path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
1639                 if (!path_renamed_outside_HEAD) {
1640                         add_cacheinfo(mfi.mode, mfi.sha, path,
1641                                       0, (!o->call_depth), 0);
1642                         return mfi.clean;
1643                 }
1644         } else
1645                 output(o, 2, _("Auto-merging %s"), path);
1646
1647         if (!mfi.clean) {
1648                 if (S_ISGITLINK(mfi.mode))
1649                         reason = _("submodule");
1650                 output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
1651                                 reason, path);
1652                 if (rename_conflict_info && !df_conflict_remains)
1653                         update_stages(path, &one, &a, &b);
1654         }
1655
1656         if (df_conflict_remains) {
1657                 char *new_path;
1658                 if (o->call_depth) {
1659                         remove_file_from_cache(path);
1660                 } else {
1661                         if (!mfi.clean)
1662                                 update_stages(path, &one, &a, &b);
1663                         else {
1664                                 int file_from_stage2 = was_tracked(path);
1665                                 struct diff_filespec merged;
1666                                 hashcpy(merged.sha1, mfi.sha);
1667                                 merged.mode = mfi.mode;
1668
1669                                 update_stages(path, NULL,
1670                                               file_from_stage2 ? &merged : NULL,
1671                                               file_from_stage2 ? NULL : &merged);
1672                         }
1673
1674                 }
1675                 new_path = unique_path(o, path, rename_conflict_info->branch1);
1676                 output(o, 1, _("Adding as %s instead"), new_path);
1677                 update_file(o, 0, mfi.sha, mfi.mode, new_path);
1678                 free(new_path);
1679                 mfi.clean = 0;
1680         } else {
1681                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1682         }
1683         return mfi.clean;
1684
1685 }
1686
1687 /* Per entry merge function */
1688 static int process_entry(struct merge_options *o,
1689                          const char *path, struct stage_data *entry)
1690 {
1691         /*
1692         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1693         print_index_entry("\tpath: ", entry);
1694         */
1695         int clean_merge = 1;
1696         int normalize = o->renormalize;
1697         unsigned o_mode = entry->stages[1].mode;
1698         unsigned a_mode = entry->stages[2].mode;
1699         unsigned b_mode = entry->stages[3].mode;
1700         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1701         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1702         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1703
1704         entry->processed = 1;
1705         if (entry->rename_conflict_info) {
1706                 struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
1707                 switch (conflict_info->rename_type) {
1708                 case RENAME_NORMAL:
1709                 case RENAME_ONE_FILE_TO_ONE:
1710                         clean_merge = merge_content(o, path,
1711                                                     o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1712                                                     conflict_info);
1713                         break;
1714                 case RENAME_DELETE:
1715                         clean_merge = 0;
1716                         conflict_rename_delete(o, conflict_info->pair1,
1717                                                conflict_info->branch1,
1718                                                conflict_info->branch2);
1719                         break;
1720                 case RENAME_ONE_FILE_TO_TWO:
1721                         clean_merge = 0;
1722                         conflict_rename_rename_1to2(o, conflict_info);
1723                         break;
1724                 case RENAME_TWO_FILES_TO_ONE:
1725                         clean_merge = 0;
1726                         conflict_rename_rename_2to1(o, conflict_info);
1727                         break;
1728                 default:
1729                         entry->processed = 0;
1730                         break;
1731                 }
1732         } else if (o_sha && (!a_sha || !b_sha)) {
1733                 /* Case A: Deleted in one */
1734                 if ((!a_sha && !b_sha) ||
1735                     (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1736                     (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1737                         /* Deleted in both or deleted in one and
1738                          * unchanged in the other */
1739                         if (a_sha)
1740                                 output(o, 2, _("Removing %s"), path);
1741                         /* do not touch working file if it did not exist */
1742                         remove_file(o, 1, path, !a_sha);
1743                 } else {
1744                         /* Modify/delete; deleted side may have put a directory in the way */
1745                         clean_merge = 0;
1746                         handle_modify_delete(o, path, o_sha, o_mode,
1747                                              a_sha, a_mode, b_sha, b_mode);
1748                 }
1749         } else if ((!o_sha && a_sha && !b_sha) ||
1750                    (!o_sha && !a_sha && b_sha)) {
1751                 /* Case B: Added in one. */
1752                 /* [nothing|directory] -> ([nothing|directory], file) */
1753
1754                 const char *add_branch;
1755                 const char *other_branch;
1756                 unsigned mode;
1757                 const unsigned char *sha;
1758                 const char *conf;
1759
1760                 if (a_sha) {
1761                         add_branch = o->branch1;
1762                         other_branch = o->branch2;
1763                         mode = a_mode;
1764                         sha = a_sha;
1765                         conf = _("file/directory");
1766                 } else {
1767                         add_branch = o->branch2;
1768                         other_branch = o->branch1;
1769                         mode = b_mode;
1770                         sha = b_sha;
1771                         conf = _("directory/file");
1772                 }
1773                 if (dir_in_way(path, !o->call_depth)) {
1774                         char *new_path = unique_path(o, path, add_branch);
1775                         clean_merge = 0;
1776                         output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
1777                                "Adding %s as %s"),
1778                                conf, path, other_branch, path, new_path);
1779                         if (o->call_depth)
1780                                 remove_file_from_cache(path);
1781                         update_file(o, 0, sha, mode, new_path);
1782                         if (o->call_depth)
1783                                 remove_file_from_cache(path);
1784                         free(new_path);
1785                 } else {
1786                         output(o, 2, _("Adding %s"), path);
1787                         /* do not overwrite file if already present */
1788                         update_file_flags(o, sha, mode, path, 1, !a_sha);
1789                 }
1790         } else if (a_sha && b_sha) {
1791                 /* Case C: Added in both (check for same permissions) and */
1792                 /* case D: Modified in both, but differently. */
1793                 clean_merge = merge_content(o, path,
1794                                             o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1795                                             NULL);
1796         } else if (!o_sha && !a_sha && !b_sha) {
1797                 /*
1798                  * this entry was deleted altogether. a_mode == 0 means
1799                  * we had that path and want to actively remove it.
1800                  */
1801                 remove_file(o, 1, path, !a_mode);
1802         } else
1803                 die(_("Fatal merge failure, shouldn't happen."));
1804
1805         return clean_merge;
1806 }
1807
1808 int merge_trees(struct merge_options *o,
1809                 struct tree *head,
1810                 struct tree *merge,
1811                 struct tree *common,
1812                 struct tree **result)
1813 {
1814         int code, clean;
1815
1816         if (o->subtree_shift) {
1817                 merge = shift_tree_object(head, merge, o->subtree_shift);
1818                 common = shift_tree_object(head, common, o->subtree_shift);
1819         }
1820
1821         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1822                 output(o, 0, _("Already up-to-date!"));
1823                 *result = head;
1824                 return 1;
1825         }
1826
1827         code = git_merge_trees(o->call_depth, common, head, merge);
1828
1829         if (code != 0) {
1830                 if (show(o, 4) || o->call_depth)
1831                         die(_("merging of trees %s and %s failed"),
1832                             sha1_to_hex(head->object.sha1),
1833                             sha1_to_hex(merge->object.sha1));
1834                 else
1835                         exit(128);
1836         }
1837
1838         if (unmerged_cache()) {
1839                 struct string_list *entries, *re_head, *re_merge;
1840                 int i;
1841                 string_list_clear(&o->current_file_set, 1);
1842                 string_list_clear(&o->current_directory_set, 1);
1843                 get_files_dirs(o, head);
1844                 get_files_dirs(o, merge);
1845
1846                 entries = get_unmerged();
1847                 record_df_conflict_files(o, entries);
1848                 re_head  = get_renames(o, head, common, head, merge, entries);
1849                 re_merge = get_renames(o, merge, common, head, merge, entries);
1850                 clean = process_renames(o, re_head, re_merge);
1851                 for (i = entries->nr-1; 0 <= i; i--) {
1852                         const char *path = entries->items[i].string;
1853                         struct stage_data *e = entries->items[i].util;
1854                         if (!e->processed
1855                                 && !process_entry(o, path, e))
1856                                 clean = 0;
1857                 }
1858                 for (i = 0; i < entries->nr; i++) {
1859                         struct stage_data *e = entries->items[i].util;
1860                         if (!e->processed)
1861                                 die(_("Unprocessed path??? %s"),
1862                                     entries->items[i].string);
1863                 }
1864
1865                 string_list_clear(re_merge, 0);
1866                 string_list_clear(re_head, 0);
1867                 string_list_clear(entries, 1);
1868
1869         }
1870         else
1871                 clean = 1;
1872
1873         if (o->call_depth)
1874                 *result = write_tree_from_memory(o);
1875
1876         return clean;
1877 }
1878
1879 static struct commit_list *reverse_commit_list(struct commit_list *list)
1880 {
1881         struct commit_list *next = NULL, *current, *backup;
1882         for (current = list; current; current = backup) {
1883                 backup = current->next;
1884                 current->next = next;
1885                 next = current;
1886         }
1887         return next;
1888 }
1889
1890 /*
1891  * Merge the commits h1 and h2, return the resulting virtual
1892  * commit object and a flag indicating the cleanness of the merge.
1893  */
1894 int merge_recursive(struct merge_options *o,
1895                     struct commit *h1,
1896                     struct commit *h2,
1897                     struct commit_list *ca,
1898                     struct commit **result)
1899 {
1900         struct commit_list *iter;
1901         struct commit *merged_common_ancestors;
1902         struct tree *mrtree = mrtree;
1903         int clean;
1904
1905         if (show(o, 4)) {
1906                 output(o, 4, _("Merging:"));
1907                 output_commit_title(o, h1);
1908                 output_commit_title(o, h2);
1909         }
1910
1911         if (!ca) {
1912                 ca = get_merge_bases(h1, h2, 1);
1913                 ca = reverse_commit_list(ca);
1914         }
1915
1916         if (show(o, 5)) {
1917                 unsigned cnt = commit_list_count(ca);
1918
1919                 output(o, 5, Q_("found %u common ancestor:",
1920                                 "found %u common ancestors:", cnt), cnt);
1921                 for (iter = ca; iter; iter = iter->next)
1922                         output_commit_title(o, iter->item);
1923         }
1924
1925         merged_common_ancestors = pop_commit(&ca);
1926         if (merged_common_ancestors == NULL) {
1927                 /* if there is no common ancestor, use an empty tree */
1928                 struct tree *tree;
1929
1930                 tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
1931                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1932         }
1933
1934         for (iter = ca; iter; iter = iter->next) {
1935                 const char *saved_b1, *saved_b2;
1936                 o->call_depth++;
1937                 /*
1938                  * When the merge fails, the result contains files
1939                  * with conflict markers. The cleanness flag is
1940                  * ignored, it was never actually used, as result of
1941                  * merge_trees has always overwritten it: the committed
1942                  * "conflicts" were already resolved.
1943                  */
1944                 discard_cache();
1945                 saved_b1 = o->branch1;
1946                 saved_b2 = o->branch2;
1947                 o->branch1 = "Temporary merge branch 1";
1948                 o->branch2 = "Temporary merge branch 2";
1949                 merge_recursive(o, merged_common_ancestors, iter->item,
1950                                 NULL, &merged_common_ancestors);
1951                 o->branch1 = saved_b1;
1952                 o->branch2 = saved_b2;
1953                 o->call_depth--;
1954
1955                 if (!merged_common_ancestors)
1956                         die(_("merge returned no commit"));
1957         }
1958
1959         discard_cache();
1960         if (!o->call_depth)
1961                 read_cache();
1962
1963         o->ancestor = "merged common ancestors";
1964         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1965                             &mrtree);
1966
1967         if (o->call_depth) {
1968                 *result = make_virtual_commit(mrtree, "merged tree");
1969                 commit_list_insert(h1, &(*result)->parents);
1970                 commit_list_insert(h2, &(*result)->parents->next);
1971         }
1972         flush_output(o);
1973         if (show(o, 2))
1974                 diff_warn_rename_limit("merge.renamelimit",
1975                                        o->needed_rename_limit, 0);
1976         return clean;
1977 }
1978
1979 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1980 {
1981         struct object *object;
1982
1983         object = deref_tag(parse_object(sha1), name, strlen(name));
1984         if (!object)
1985                 return NULL;
1986         if (object->type == OBJ_TREE)
1987                 return make_virtual_commit((struct tree*)object, name);
1988         if (object->type != OBJ_COMMIT)
1989                 return NULL;
1990         if (parse_commit((struct commit *)object))
1991                 return NULL;
1992         return (struct commit *)object;
1993 }
1994
1995 int merge_recursive_generic(struct merge_options *o,
1996                             const unsigned char *head,
1997                             const unsigned char *merge,
1998                             int num_base_list,
1999                             const unsigned char **base_list,
2000                             struct commit **result)
2001 {
2002         int clean;
2003         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
2004         struct commit *head_commit = get_ref(head, o->branch1);
2005         struct commit *next_commit = get_ref(merge, o->branch2);
2006         struct commit_list *ca = NULL;
2007
2008         if (base_list) {
2009                 int i;
2010                 for (i = 0; i < num_base_list; ++i) {
2011                         struct commit *base;
2012                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
2013                                 return error(_("Could not parse object '%s'"),
2014                                         sha1_to_hex(base_list[i]));
2015                         commit_list_insert(base, &ca);
2016                 }
2017         }
2018
2019         hold_locked_index(lock, 1);
2020         clean = merge_recursive(o, head_commit, next_commit, ca,
2021                         result);
2022         if (active_cache_changed &&
2023             write_locked_index(&the_index, lock, COMMIT_LOCK))
2024                 return error(_("Unable to write index."));
2025
2026         return clean ? 0 : 1;
2027 }
2028
2029 static int merge_recursive_config(const char *var, const char *value, void *cb)
2030 {
2031         struct merge_options *o = cb;
2032         if (!strcmp(var, "merge.verbosity")) {
2033                 o->verbosity = git_config_int(var, value);
2034                 return 0;
2035         }
2036         if (!strcmp(var, "diff.renamelimit")) {
2037                 o->diff_rename_limit = git_config_int(var, value);
2038                 return 0;
2039         }
2040         if (!strcmp(var, "merge.renamelimit")) {
2041                 o->merge_rename_limit = git_config_int(var, value);
2042                 return 0;
2043         }
2044         return git_xmerge_config(var, value, cb);
2045 }
2046
2047 void init_merge_options(struct merge_options *o)
2048 {
2049         memset(o, 0, sizeof(struct merge_options));
2050         o->verbosity = 2;
2051         o->buffer_output = 1;
2052         o->diff_rename_limit = -1;
2053         o->merge_rename_limit = -1;
2054         o->renormalize = 0;
2055         git_config(merge_recursive_config, o);
2056         if (getenv("GIT_MERGE_VERBOSITY"))
2057                 o->verbosity =
2058                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
2059         if (o->verbosity >= 5)
2060                 o->buffer_output = 0;
2061         strbuf_init(&o->obuf, 0);
2062         string_list_init(&o->current_file_set, 1);
2063         string_list_init(&o->current_directory_set, 1);
2064         string_list_init(&o->df_conflict_file_set, 1);
2065 }
2066
2067 int parse_merge_opt(struct merge_options *o, const char *s)
2068 {
2069         const char *arg;
2070
2071         if (!s || !*s)
2072                 return -1;
2073         if (!strcmp(s, "ours"))
2074                 o->recursive_variant = MERGE_RECURSIVE_OURS;
2075         else if (!strcmp(s, "theirs"))
2076                 o->recursive_variant = MERGE_RECURSIVE_THEIRS;
2077         else if (!strcmp(s, "subtree"))
2078                 o->subtree_shift = "";
2079         else if (skip_prefix(s, "subtree=", &arg))
2080                 o->subtree_shift = arg;
2081         else if (!strcmp(s, "patience"))
2082                 o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF);
2083         else if (!strcmp(s, "histogram"))
2084                 o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF);
2085         else if (skip_prefix(s, "diff-algorithm=", &arg)) {
2086                 long value = parse_algorithm_value(arg);
2087                 if (value < 0)
2088                         return -1;
2089                 /* clear out previous settings */
2090                 DIFF_XDL_CLR(o, NEED_MINIMAL);
2091                 o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
2092                 o->xdl_opts |= value;
2093         }
2094         else if (!strcmp(s, "ignore-space-change"))
2095                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2096         else if (!strcmp(s, "ignore-all-space"))
2097                 o->xdl_opts |= XDF_IGNORE_WHITESPACE;
2098         else if (!strcmp(s, "ignore-space-at-eol"))
2099                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2100         else if (!strcmp(s, "renormalize"))
2101                 o->renormalize = 1;
2102         else if (!strcmp(s, "no-renormalize"))
2103                 o->renormalize = 0;
2104         else if (skip_prefix(s, "rename-threshold=", &arg)) {
2105                 if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
2106                         return -1;
2107         }
2108         else
2109                 return -1;
2110         return 0;
2111 }