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