Code

Merge branch 'maint'
[git.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"
25 static const char rename_limit_advice[] =
26 "inexact rename detection was skipped because there were too many\n"
27 "  files. You may want to set your merge.renamelimit variable to at least\n"
28 "  %d and retry this merge.";
30 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
31                                       const char *subtree_shift)
32 {
33         unsigned char shifted[20];
35         if (!*subtree_shift) {
36                 shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
37         } else {
38                 shift_tree_by(one->object.sha1, two->object.sha1, shifted,
39                               subtree_shift);
40         }
41         if (!hashcmp(two->object.sha1, shifted))
42                 return two;
43         return lookup_tree(shifted);
44 }
46 /*
47  * A virtual commit has (const char *)commit->util set to the name.
48  */
50 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
51 {
52         struct commit *commit = xcalloc(1, sizeof(struct commit));
53         commit->tree = tree;
54         commit->util = (void*)comment;
55         /* avoid warnings */
56         commit->object.parsed = 1;
57         return commit;
58 }
60 /*
61  * Since we use get_tree_entry(), which does not put the read object into
62  * the object pool, we cannot rely on a == b.
63  */
64 static int sha_eq(const unsigned char *a, const unsigned char *b)
65 {
66         if (!a && !b)
67                 return 2;
68         return a && b && hashcmp(a, b) == 0;
69 }
71 enum rename_type {
72         RENAME_NORMAL = 0,
73         RENAME_DELETE,
74         RENAME_ONE_FILE_TO_TWO
75 };
77 struct rename_df_conflict_info {
78         enum rename_type rename_type;
79         struct diff_filepair *pair1;
80         struct diff_filepair *pair2;
81         const char *branch1;
82         const char *branch2;
83         struct stage_data *dst_entry1;
84         struct stage_data *dst_entry2;
85 };
87 /*
88  * Since we want to write the index eventually, we cannot reuse the index
89  * for these (temporary) data.
90  */
91 struct stage_data {
92         struct {
93                 unsigned mode;
94                 unsigned char sha[20];
95         } stages[4];
96         struct rename_df_conflict_info *rename_df_conflict_info;
97         unsigned processed:1;
98 };
100 static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
101                                                  struct diff_filepair *pair1,
102                                                  struct diff_filepair *pair2,
103                                                  const char *branch1,
104                                                  const char *branch2,
105                                                  struct stage_data *dst_entry1,
106                                                  struct stage_data *dst_entry2)
108         struct rename_df_conflict_info *ci = xcalloc(1, sizeof(struct rename_df_conflict_info));
109         ci->rename_type = rename_type;
110         ci->pair1 = pair1;
111         ci->branch1 = branch1;
112         ci->branch2 = branch2;
114         ci->dst_entry1 = dst_entry1;
115         dst_entry1->rename_df_conflict_info = ci;
116         dst_entry1->processed = 0;
118         assert(!pair2 == !dst_entry2);
119         if (dst_entry2) {
120                 ci->dst_entry2 = dst_entry2;
121                 ci->pair2 = pair2;
122                 dst_entry2->rename_df_conflict_info = ci;
123                 dst_entry2->processed = 0;
124         }
127 static int show(struct merge_options *o, int v)
129         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
132 static void flush_output(struct merge_options *o)
134         if (o->obuf.len) {
135                 fputs(o->obuf.buf, stdout);
136                 strbuf_reset(&o->obuf);
137         }
140 __attribute__((format (printf, 3, 4)))
141 static void output(struct merge_options *o, int v, const char *fmt, ...)
143         va_list ap;
145         if (!show(o, v))
146                 return;
148         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
149         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
150         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
152         va_start(ap, fmt);
153         strbuf_vaddf(&o->obuf, fmt, ap);
154         va_end(ap);
156         strbuf_add(&o->obuf, "\n", 1);
157         if (!o->buffer_output)
158                 flush_output(o);
161 static void output_commit_title(struct merge_options *o, struct commit *commit)
163         int i;
164         flush_output(o);
165         for (i = o->call_depth; i--;)
166                 fputs("  ", stdout);
167         if (commit->util)
168                 printf("virtual %s\n", (char *)commit->util);
169         else {
170                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
171                 if (parse_commit(commit) != 0)
172                         printf("(bad commit)\n");
173                 else {
174                         const char *title;
175                         int len = find_commit_subject(commit->buffer, &title);
176                         if (len)
177                                 printf("%.*s\n", len, title);
178                 }
179         }
182 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
183                 const char *path, int stage, int refresh, int options)
185         struct cache_entry *ce;
186         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
187         if (!ce)
188                 return error("addinfo_cache failed for path '%s'", path);
189         return add_cache_entry(ce, options);
192 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
194         parse_tree(tree);
195         init_tree_desc(desc, tree->buffer, tree->size);
198 static int git_merge_trees(int index_only,
199                            struct tree *common,
200                            struct tree *head,
201                            struct tree *merge)
203         int rc;
204         struct tree_desc t[3];
205         struct unpack_trees_options opts;
207         memset(&opts, 0, sizeof(opts));
208         if (index_only)
209                 opts.index_only = 1;
210         else
211                 opts.update = 1;
212         opts.merge = 1;
213         opts.head_idx = 2;
214         opts.fn = threeway_merge;
215         opts.src_index = &the_index;
216         opts.dst_index = &the_index;
217         setup_unpack_trees_porcelain(&opts, "merge");
219         init_tree_desc_from_tree(t+0, common);
220         init_tree_desc_from_tree(t+1, head);
221         init_tree_desc_from_tree(t+2, merge);
223         rc = unpack_trees(3, t, &opts);
224         cache_tree_free(&active_cache_tree);
225         return rc;
228 struct tree *write_tree_from_memory(struct merge_options *o)
230         struct tree *result = NULL;
232         if (unmerged_cache()) {
233                 int i;
234                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
235                 for (i = 0; i < active_nr; i++) {
236                         struct cache_entry *ce = active_cache[i];
237                         if (ce_stage(ce))
238                                 fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
239                                         (int)ce_namelen(ce), ce->name);
240                 }
241                 die("Bug in merge-recursive.c");
242         }
244         if (!active_cache_tree)
245                 active_cache_tree = cache_tree();
247         if (!cache_tree_fully_valid(active_cache_tree) &&
248             cache_tree_update(active_cache_tree,
249                               active_cache, active_nr, 0, 0) < 0)
250                 die("error building trees");
252         result = lookup_tree(active_cache_tree->sha1);
254         return result;
257 static int save_files_dirs(const unsigned char *sha1,
258                 const char *base, int baselen, const char *path,
259                 unsigned int mode, int stage, void *context)
261         int len = strlen(path);
262         char *newpath = xmalloc(baselen + len + 1);
263         struct merge_options *o = context;
265         memcpy(newpath, base, baselen);
266         memcpy(newpath + baselen, path, len);
267         newpath[baselen + len] = '\0';
269         if (S_ISDIR(mode))
270                 string_list_insert(&o->current_directory_set, newpath);
271         else
272                 string_list_insert(&o->current_file_set, newpath);
273         free(newpath);
275         return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
278 static int get_files_dirs(struct merge_options *o, struct tree *tree)
280         int n;
281         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
282                 return 0;
283         n = o->current_file_set.nr + o->current_directory_set.nr;
284         return n;
287 /*
288  * Returns an index_entry instance which doesn't have to correspond to
289  * a real cache entry in Git's index.
290  */
291 static struct stage_data *insert_stage_data(const char *path,
292                 struct tree *o, struct tree *a, struct tree *b,
293                 struct string_list *entries)
295         struct string_list_item *item;
296         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
297         get_tree_entry(o->object.sha1, path,
298                         e->stages[1].sha, &e->stages[1].mode);
299         get_tree_entry(a->object.sha1, path,
300                         e->stages[2].sha, &e->stages[2].mode);
301         get_tree_entry(b->object.sha1, path,
302                         e->stages[3].sha, &e->stages[3].mode);
303         item = string_list_insert(entries, path);
304         item->util = e;
305         return e;
308 /*
309  * Create a dictionary mapping file names to stage_data objects. The
310  * dictionary contains one entry for every path with a non-zero stage entry.
311  */
312 static struct string_list *get_unmerged(void)
314         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
315         int i;
317         unmerged->strdup_strings = 1;
319         for (i = 0; i < active_nr; i++) {
320                 struct string_list_item *item;
321                 struct stage_data *e;
322                 struct cache_entry *ce = active_cache[i];
323                 if (!ce_stage(ce))
324                         continue;
326                 item = string_list_lookup(unmerged, ce->name);
327                 if (!item) {
328                         item = string_list_insert(unmerged, ce->name);
329                         item->util = xcalloc(1, sizeof(struct stage_data));
330                 }
331                 e = item->util;
332                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
333                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
334         }
336         return unmerged;
339 static void make_room_for_directories_of_df_conflicts(struct merge_options *o,
340                                                       struct string_list *entries)
342         /* If there are D/F conflicts, and the paths currently exist
343          * in the working copy as a file, we want to remove them to
344          * make room for the corresponding directory.  Such paths will
345          * later be processed in process_df_entry() at the end.  If
346          * the corresponding directory ends up being removed by the
347          * merge, then the file will be reinstated at that time;
348          * otherwise, if the file is not supposed to be removed by the
349          * merge, the contents of the file will be placed in another
350          * unique filename.
351          *
352          * NOTE: This function relies on the fact that entries for a
353          * D/F conflict will appear adjacent in the index, with the
354          * entries for the file appearing before entries for paths
355          * below the corresponding directory.
356          */
357         const char *last_file = NULL;
358         int last_len = 0;
359         struct stage_data *last_e;
360         int i;
362         for (i = 0; i < entries->nr; i++) {
363                 const char *path = entries->items[i].string;
364                 int len = strlen(path);
365                 struct stage_data *e = entries->items[i].util;
367                 /*
368                  * Check if last_file & path correspond to a D/F conflict;
369                  * i.e. whether path is last_file+'/'+<something>.
370                  * If so, remove last_file to make room for path and friends.
371                  */
372                 if (last_file &&
373                     len > last_len &&
374                     memcmp(path, last_file, last_len) == 0 &&
375                     path[last_len] == '/') {
376                         output(o, 3, "Removing %s to make room for subdirectory; may re-add later.", last_file);
377                         unlink(last_file);
378                 }
380                 /*
381                  * Determine whether path could exist as a file in the
382                  * working directory as a possible D/F conflict.  This
383                  * will only occur when it exists in stage 2 as a
384                  * file.
385                  */
386                 if (S_ISREG(e->stages[2].mode) || S_ISLNK(e->stages[2].mode)) {
387                         last_file = path;
388                         last_len = len;
389                         last_e = e;
390                 } else {
391                         last_file = NULL;
392                 }
393         }
396 struct rename {
397         struct diff_filepair *pair;
398         struct stage_data *src_entry;
399         struct stage_data *dst_entry;
400         unsigned processed:1;
401 };
403 /*
404  * Get information of all renames which occurred between 'o_tree' and
405  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
406  * 'b_tree') to be able to associate the correct cache entries with
407  * the rename information. 'tree' is always equal to either a_tree or b_tree.
408  */
409 static struct string_list *get_renames(struct merge_options *o,
410                                        struct tree *tree,
411                                        struct tree *o_tree,
412                                        struct tree *a_tree,
413                                        struct tree *b_tree,
414                                        struct string_list *entries)
416         int i;
417         struct string_list *renames;
418         struct diff_options opts;
420         renames = xcalloc(1, sizeof(struct string_list));
421         diff_setup(&opts);
422         DIFF_OPT_SET(&opts, RECURSIVE);
423         opts.detect_rename = DIFF_DETECT_RENAME;
424         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
425                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
426                             1000;
427         opts.rename_score = o->rename_score;
428         opts.show_rename_progress = o->show_rename_progress;
429         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
430         if (diff_setup_done(&opts) < 0)
431                 die("diff setup failed");
432         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
433         diffcore_std(&opts);
434         if (opts.needed_rename_limit > o->needed_rename_limit)
435                 o->needed_rename_limit = opts.needed_rename_limit;
436         for (i = 0; i < diff_queued_diff.nr; ++i) {
437                 struct string_list_item *item;
438                 struct rename *re;
439                 struct diff_filepair *pair = diff_queued_diff.queue[i];
440                 if (pair->status != 'R') {
441                         diff_free_filepair(pair);
442                         continue;
443                 }
444                 re = xmalloc(sizeof(*re));
445                 re->processed = 0;
446                 re->pair = pair;
447                 item = string_list_lookup(entries, re->pair->one->path);
448                 if (!item)
449                         re->src_entry = insert_stage_data(re->pair->one->path,
450                                         o_tree, a_tree, b_tree, entries);
451                 else
452                         re->src_entry = item->util;
454                 item = string_list_lookup(entries, re->pair->two->path);
455                 if (!item)
456                         re->dst_entry = insert_stage_data(re->pair->two->path,
457                                         o_tree, a_tree, b_tree, entries);
458                 else
459                         re->dst_entry = item->util;
460                 item = string_list_insert(renames, pair->one->path);
461                 item->util = re;
462         }
463         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
464         diff_queued_diff.nr = 0;
465         diff_flush(&opts);
466         return renames;
469 static int update_stages_options(const char *path, struct diff_filespec *o,
470                          struct diff_filespec *a, struct diff_filespec *b,
471                          int clear, int options)
473         if (clear)
474                 if (remove_file_from_cache(path))
475                         return -1;
476         if (o)
477                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
478                         return -1;
479         if (a)
480                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
481                         return -1;
482         if (b)
483                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
484                         return -1;
485         return 0;
488 static int update_stages(const char *path, struct diff_filespec *o,
489                          struct diff_filespec *a, struct diff_filespec *b,
490                          int clear)
492         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
493         return update_stages_options(path, o, a, b, clear, options);
496 static int update_stages_and_entry(const char *path,
497                                    struct stage_data *entry,
498                                    struct diff_filespec *o,
499                                    struct diff_filespec *a,
500                                    struct diff_filespec *b,
501                                    int clear)
503         int options;
505         entry->processed = 0;
506         entry->stages[1].mode = o->mode;
507         entry->stages[2].mode = a->mode;
508         entry->stages[3].mode = b->mode;
509         hashcpy(entry->stages[1].sha, o->sha1);
510         hashcpy(entry->stages[2].sha, a->sha1);
511         hashcpy(entry->stages[3].sha, b->sha1);
512         options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
513         return update_stages_options(path, o, a, b, clear, options);
516 static int remove_file(struct merge_options *o, int clean,
517                        const char *path, int no_wd)
519         int update_cache = o->call_depth || clean;
520         int update_working_directory = !o->call_depth && !no_wd;
522         if (update_cache) {
523                 if (remove_file_from_cache(path))
524                         return -1;
525         }
526         if (update_working_directory) {
527                 if (remove_path(path))
528                         return -1;
529         }
530         return 0;
533 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
535         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
536         int suffix = 0;
537         struct stat st;
538         char *p = newpath + strlen(path);
539         strcpy(newpath, path);
540         *(p++) = '~';
541         strcpy(p, branch);
542         for (; *p; ++p)
543                 if ('/' == *p)
544                         *p = '_';
545         while (string_list_has_string(&o->current_file_set, newpath) ||
546                string_list_has_string(&o->current_directory_set, newpath) ||
547                lstat(newpath, &st) == 0)
548                 sprintf(p, "_%d", suffix++);
550         string_list_insert(&o->current_file_set, newpath);
551         return newpath;
554 static void flush_buffer(int fd, const char *buf, unsigned long size)
556         while (size > 0) {
557                 long ret = write_in_full(fd, buf, size);
558                 if (ret < 0) {
559                         /* Ignore epipe */
560                         if (errno == EPIPE)
561                                 break;
562                         die_errno("merge-recursive");
563                 } else if (!ret) {
564                         die("merge-recursive: disk full?");
565                 }
566                 size -= ret;
567                 buf += ret;
568         }
571 static int would_lose_untracked(const char *path)
573         int pos = cache_name_pos(path, strlen(path));
575         if (pos < 0)
576                 pos = -1 - pos;
577         while (pos < active_nr &&
578                !strcmp(path, active_cache[pos]->name)) {
579                 /*
580                  * If stage #0, it is definitely tracked.
581                  * If it has stage #2 then it was tracked
582                  * before this merge started.  All other
583                  * cases the path was not tracked.
584                  */
585                 switch (ce_stage(active_cache[pos])) {
586                 case 0:
587                 case 2:
588                         return 0;
589                 }
590                 pos++;
591         }
592         return file_exists(path);
595 static int make_room_for_path(const char *path)
597         int status;
598         const char *msg = "failed to create path '%s'%s";
600         status = safe_create_leading_directories_const(path);
601         if (status) {
602                 if (status == -3) {
603                         /* something else exists */
604                         error(msg, path, ": perhaps a D/F conflict?");
605                         return -1;
606                 }
607                 die(msg, path, "");
608         }
610         /*
611          * Do not unlink a file in the work tree if we are not
612          * tracking it.
613          */
614         if (would_lose_untracked(path))
615                 return error("refusing to lose untracked file at '%s'",
616                              path);
618         /* Successful unlink is good.. */
619         if (!unlink(path))
620                 return 0;
621         /* .. and so is no existing file */
622         if (errno == ENOENT)
623                 return 0;
624         /* .. but not some other error (who really cares what?) */
625         return error(msg, path, ": perhaps a D/F conflict?");
628 static void update_file_flags(struct merge_options *o,
629                               const unsigned char *sha,
630                               unsigned mode,
631                               const char *path,
632                               int update_cache,
633                               int update_wd)
635         if (o->call_depth)
636                 update_wd = 0;
638         if (update_wd) {
639                 enum object_type type;
640                 void *buf;
641                 unsigned long size;
643                 if (S_ISGITLINK(mode)) {
644                         /*
645                          * We may later decide to recursively descend into
646                          * the submodule directory and update its index
647                          * and/or work tree, but we do not do that now.
648                          */
649                         update_wd = 0;
650                         goto update_index;
651                 }
653                 buf = read_sha1_file(sha, &type, &size);
654                 if (!buf)
655                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
656                 if (type != OBJ_BLOB)
657                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
658                 if (S_ISREG(mode)) {
659                         struct strbuf strbuf = STRBUF_INIT;
660                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
661                                 free(buf);
662                                 size = strbuf.len;
663                                 buf = strbuf_detach(&strbuf, NULL);
664                         }
665                 }
667                 if (make_room_for_path(path) < 0) {
668                         update_wd = 0;
669                         free(buf);
670                         goto update_index;
671                 }
672                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
673                         int fd;
674                         if (mode & 0100)
675                                 mode = 0777;
676                         else
677                                 mode = 0666;
678                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
679                         if (fd < 0)
680                                 die_errno("failed to open '%s'", path);
681                         flush_buffer(fd, buf, size);
682                         close(fd);
683                 } else if (S_ISLNK(mode)) {
684                         char *lnk = xmemdupz(buf, size);
685                         safe_create_leading_directories_const(path);
686                         unlink(path);
687                         if (symlink(lnk, path))
688                                 die_errno("failed to symlink '%s'", path);
689                         free(lnk);
690                 } else
691                         die("do not know what to do with %06o %s '%s'",
692                             mode, sha1_to_hex(sha), path);
693                 free(buf);
694         }
695  update_index:
696         if (update_cache)
697                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
700 static void update_file(struct merge_options *o,
701                         int clean,
702                         const unsigned char *sha,
703                         unsigned mode,
704                         const char *path)
706         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
709 /* Low level file merging, update and removal */
711 struct merge_file_info {
712         unsigned char sha[20];
713         unsigned mode;
714         unsigned clean:1,
715                  merge:1;
716 };
718 static int merge_3way(struct merge_options *o,
719                       mmbuffer_t *result_buf,
720                       struct diff_filespec *one,
721                       struct diff_filespec *a,
722                       struct diff_filespec *b,
723                       const char *branch1,
724                       const char *branch2)
726         mmfile_t orig, src1, src2;
727         struct ll_merge_options ll_opts = {0};
728         char *base_name, *name1, *name2;
729         int merge_status;
731         ll_opts.renormalize = o->renormalize;
732         ll_opts.xdl_opts = o->xdl_opts;
734         if (o->call_depth) {
735                 ll_opts.virtual_ancestor = 1;
736                 ll_opts.variant = 0;
737         } else {
738                 switch (o->recursive_variant) {
739                 case MERGE_RECURSIVE_OURS:
740                         ll_opts.variant = XDL_MERGE_FAVOR_OURS;
741                         break;
742                 case MERGE_RECURSIVE_THEIRS:
743                         ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
744                         break;
745                 default:
746                         ll_opts.variant = 0;
747                         break;
748                 }
749         }
751         if (strcmp(a->path, b->path) ||
752             (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
753                 base_name = o->ancestor == NULL ? NULL :
754                         xstrdup(mkpath("%s:%s", o->ancestor, one->path));
755                 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
756                 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
757         } else {
758                 base_name = o->ancestor == NULL ? NULL :
759                         xstrdup(mkpath("%s", o->ancestor));
760                 name1 = xstrdup(mkpath("%s", branch1));
761                 name2 = xstrdup(mkpath("%s", branch2));
762         }
764         read_mmblob(&orig, one->sha1);
765         read_mmblob(&src1, a->sha1);
766         read_mmblob(&src2, b->sha1);
768         merge_status = ll_merge(result_buf, a->path, &orig, base_name,
769                                 &src1, name1, &src2, name2, &ll_opts);
771         free(name1);
772         free(name2);
773         free(orig.ptr);
774         free(src1.ptr);
775         free(src2.ptr);
776         return merge_status;
779 static struct merge_file_info merge_file(struct merge_options *o,
780                                          struct diff_filespec *one,
781                                          struct diff_filespec *a,
782                                          struct diff_filespec *b,
783                                          const char *branch1,
784                                          const char *branch2)
786         struct merge_file_info result;
787         result.merge = 0;
788         result.clean = 1;
790         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
791                 result.clean = 0;
792                 if (S_ISREG(a->mode)) {
793                         result.mode = a->mode;
794                         hashcpy(result.sha, a->sha1);
795                 } else {
796                         result.mode = b->mode;
797                         hashcpy(result.sha, b->sha1);
798                 }
799         } else {
800                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
801                         result.merge = 1;
803                 /*
804                  * Merge modes
805                  */
806                 if (a->mode == b->mode || a->mode == one->mode)
807                         result.mode = b->mode;
808                 else {
809                         result.mode = a->mode;
810                         if (b->mode != one->mode) {
811                                 result.clean = 0;
812                                 result.merge = 1;
813                         }
814                 }
816                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
817                         hashcpy(result.sha, b->sha1);
818                 else if (sha_eq(b->sha1, one->sha1))
819                         hashcpy(result.sha, a->sha1);
820                 else if (S_ISREG(a->mode)) {
821                         mmbuffer_t result_buf;
822                         int merge_status;
824                         merge_status = merge_3way(o, &result_buf, one, a, b,
825                                                   branch1, branch2);
827                         if ((merge_status < 0) || !result_buf.ptr)
828                                 die("Failed to execute internal merge");
830                         if (write_sha1_file(result_buf.ptr, result_buf.size,
831                                             blob_type, result.sha))
832                                 die("Unable to add %s to database",
833                                     a->path);
835                         free(result_buf.ptr);
836                         result.clean = (merge_status == 0);
837                 } else if (S_ISGITLINK(a->mode)) {
838                         result.clean = merge_submodule(result.sha, one->path, one->sha1,
839                                                        a->sha1, b->sha1);
840                 } else if (S_ISLNK(a->mode)) {
841                         hashcpy(result.sha, a->sha1);
843                         if (!sha_eq(a->sha1, b->sha1))
844                                 result.clean = 0;
845                 } else {
846                         die("unsupported object type in the tree");
847                 }
848         }
850         return result;
853 static void conflict_rename_delete(struct merge_options *o,
854                                    struct diff_filepair *pair,
855                                    const char *rename_branch,
856                                    const char *other_branch)
858         char *dest_name = pair->two->path;
859         int df_conflict = 0;
860         struct stat st;
862         output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
863                "and deleted in %s",
864                pair->one->path, pair->two->path, rename_branch,
865                other_branch);
866         if (!o->call_depth)
867                 update_stages(dest_name, NULL,
868                               rename_branch == o->branch1 ? pair->two : NULL,
869                               rename_branch == o->branch1 ? NULL : pair->two,
870                               1);
871         if (lstat(dest_name, &st) == 0 && S_ISDIR(st.st_mode)) {
872                 dest_name = unique_path(o, dest_name, rename_branch);
873                 df_conflict = 1;
874         }
875         update_file(o, 0, pair->two->sha1, pair->two->mode, dest_name);
876         if (df_conflict)
877                 free(dest_name);
880 static void conflict_rename_rename_1to2(struct merge_options *o,
881                                         struct diff_filepair *pair1,
882                                         const char *branch1,
883                                         struct diff_filepair *pair2,
884                                         const char *branch2)
886         /* One file was renamed in both branches, but to different names. */
887         char *del[2];
888         int delp = 0;
889         const char *ren1_dst = pair1->two->path;
890         const char *ren2_dst = pair2->two->path;
891         const char *dst_name1 = ren1_dst;
892         const char *dst_name2 = ren2_dst;
893         struct stat st;
894         if (lstat(ren1_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
895                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
896                 output(o, 1, "%s is a directory in %s adding as %s instead",
897                        ren1_dst, branch2, dst_name1);
898         }
899         if (lstat(ren2_dst, &st) == 0 && S_ISDIR(st.st_mode)) {
900                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
901                 output(o, 1, "%s is a directory in %s adding as %s instead",
902                        ren2_dst, branch1, dst_name2);
903         }
904         if (o->call_depth) {
905                 remove_file_from_cache(dst_name1);
906                 remove_file_from_cache(dst_name2);
907                 /*
908                  * Uncomment to leave the conflicting names in the resulting tree
909                  *
910                  * update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
911                  * update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
912                  */
913         } else {
914                 update_stages(ren1_dst, NULL, pair1->two, NULL, 1);
915                 update_stages(ren2_dst, NULL, NULL, pair2->two, 1);
917                 update_file(o, 0, pair1->two->sha1, pair1->two->mode, dst_name1);
918                 update_file(o, 0, pair2->two->sha1, pair2->two->mode, dst_name2);
919         }
920         while (delp--)
921                 free(del[delp]);
924 static void conflict_rename_rename_2to1(struct merge_options *o,
925                                         struct rename *ren1,
926                                         const char *branch1,
927                                         struct rename *ren2,
928                                         const char *branch2)
930         /* Two files were renamed to the same thing. */
931         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
932         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
933         output(o, 1, "Renaming %s to %s and %s to %s instead",
934                ren1->pair->one->path, new_path1,
935                ren2->pair->one->path, new_path2);
936         remove_file(o, 0, ren1->pair->two->path, 0);
937         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
938         update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
939         free(new_path2);
940         free(new_path1);
943 static int process_renames(struct merge_options *o,
944                            struct string_list *a_renames,
945                            struct string_list *b_renames)
947         int clean_merge = 1, i, j;
948         struct string_list a_by_dst = STRING_LIST_INIT_NODUP;
949         struct string_list b_by_dst = STRING_LIST_INIT_NODUP;
950         const struct rename *sre;
952         for (i = 0; i < a_renames->nr; i++) {
953                 sre = a_renames->items[i].util;
954                 string_list_insert(&a_by_dst, sre->pair->two->path)->util
955                         = sre->dst_entry;
956         }
957         for (i = 0; i < b_renames->nr; i++) {
958                 sre = b_renames->items[i].util;
959                 string_list_insert(&b_by_dst, sre->pair->two->path)->util
960                         = sre->dst_entry;
961         }
963         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
964                 char *src;
965                 struct string_list *renames1, *renames2Dst;
966                 struct rename *ren1 = NULL, *ren2 = NULL;
967                 const char *branch1, *branch2;
968                 const char *ren1_src, *ren1_dst;
970                 if (i >= a_renames->nr) {
971                         ren2 = b_renames->items[j++].util;
972                 } else if (j >= b_renames->nr) {
973                         ren1 = a_renames->items[i++].util;
974                 } else {
975                         int compare = strcmp(a_renames->items[i].string,
976                                              b_renames->items[j].string);
977                         if (compare <= 0)
978                                 ren1 = a_renames->items[i++].util;
979                         if (compare >= 0)
980                                 ren2 = b_renames->items[j++].util;
981                 }
983                 /* TODO: refactor, so that 1/2 are not needed */
984                 if (ren1) {
985                         renames1 = a_renames;
986                         renames2Dst = &b_by_dst;
987                         branch1 = o->branch1;
988                         branch2 = o->branch2;
989                 } else {
990                         struct rename *tmp;
991                         renames1 = b_renames;
992                         renames2Dst = &a_by_dst;
993                         branch1 = o->branch2;
994                         branch2 = o->branch1;
995                         tmp = ren2;
996                         ren2 = ren1;
997                         ren1 = tmp;
998                 }
999                 src = ren1->pair->one->path;
1001                 ren1->dst_entry->processed = 1;
1002                 ren1->src_entry->processed = 1;
1004                 if (ren1->processed)
1005                         continue;
1006                 ren1->processed = 1;
1008                 ren1_src = ren1->pair->one->path;
1009                 ren1_dst = ren1->pair->two->path;
1011                 if (ren2) {
1012                         const char *ren2_src = ren2->pair->one->path;
1013                         const char *ren2_dst = ren2->pair->two->path;
1014                         /* Renamed in 1 and renamed in 2 */
1015                         if (strcmp(ren1_src, ren2_src) != 0)
1016                                 die("ren1.src != ren2.src");
1017                         ren2->dst_entry->processed = 1;
1018                         ren2->processed = 1;
1019                         if (strcmp(ren1_dst, ren2_dst) != 0) {
1020                                 setup_rename_df_conflict_info(RENAME_ONE_FILE_TO_TWO,
1021                                                               ren1->pair,
1022                                                               ren2->pair,
1023                                                               branch1,
1024                                                               branch2,
1025                                                               ren1->dst_entry,
1026                                                               ren2->dst_entry);
1027                         } else {
1028                                 remove_file(o, 1, ren1_src, 1);
1029                                 update_stages_and_entry(ren1_dst,
1030                                                         ren1->dst_entry,
1031                                                         ren1->pair->one,
1032                                                         ren1->pair->two,
1033                                                         ren2->pair->two,
1034                                                         1 /* clear */);
1035                         }
1036                 } else {
1037                         /* Renamed in 1, maybe changed in 2 */
1038                         struct string_list_item *item;
1039                         /* we only use sha1 and mode of these */
1040                         struct diff_filespec src_other, dst_other;
1041                         int try_merge;
1043                         /*
1044                          * unpack_trees loads entries from common-commit
1045                          * into stage 1, from head-commit into stage 2, and
1046                          * from merge-commit into stage 3.  We keep track
1047                          * of which side corresponds to the rename.
1048                          */
1049                         int renamed_stage = a_renames == renames1 ? 2 : 3;
1050                         int other_stage =   a_renames == renames1 ? 3 : 2;
1052                         remove_file(o, 1, ren1_src, o->call_depth || renamed_stage == 2);
1054                         hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
1055                         src_other.mode = ren1->src_entry->stages[other_stage].mode;
1056                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[other_stage].sha);
1057                         dst_other.mode = ren1->dst_entry->stages[other_stage].mode;
1058                         try_merge = 0;
1060                         if (sha_eq(src_other.sha1, null_sha1)) {
1061                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1062                                         ren1->dst_entry->processed = 0;
1063                                         setup_rename_df_conflict_info(RENAME_DELETE,
1064                                                                       ren1->pair,
1065                                                                       NULL,
1066                                                                       branch1,
1067                                                                       branch2,
1068                                                                       ren1->dst_entry,
1069                                                                       NULL);
1070                                 } else {
1071                                         clean_merge = 0;
1072                                         conflict_rename_delete(o, ren1->pair, branch1, branch2);
1073                                 }
1074                         } else if ((dst_other.mode == ren1->pair->two->mode) &&
1075                                    sha_eq(dst_other.sha1, ren1->pair->two->sha1)) {
1076                                 /* Added file on the other side
1077                                    identical to the file being
1078                                    renamed: clean merge */
1079                                 update_file(o, 1, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1080                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1081                                 const char *new_path;
1082                                 clean_merge = 0;
1083                                 try_merge = 1;
1084                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
1085                                        "%s added in %s",
1086                                        ren1_src, ren1_dst, branch1,
1087                                        ren1_dst, branch2);
1088                                 if (o->call_depth) {
1089                                         struct merge_file_info mfi;
1090                                         struct diff_filespec one, a, b;
1092                                         one.path = a.path = b.path =
1093                                                 (char *)ren1_dst;
1094                                         hashcpy(one.sha1, null_sha1);
1095                                         one.mode = 0;
1096                                         hashcpy(a.sha1, ren1->pair->two->sha1);
1097                                         a.mode = ren1->pair->two->mode;
1098                                         hashcpy(b.sha1, dst_other.sha1);
1099                                         b.mode = dst_other.mode;
1100                                         mfi = merge_file(o, &one, &a, &b,
1101                                                          branch1,
1102                                                          branch2);
1103                                         output(o, 1, "Adding merged %s", ren1_dst);
1104                                         update_file(o, 0,
1105                                                     mfi.sha,
1106                                                     mfi.mode,
1107                                                     ren1_dst);
1108                                         try_merge = 0;
1109                                 } else {
1110                                         new_path = unique_path(o, ren1_dst, branch2);
1111                                         output(o, 1, "Adding as %s instead", new_path);
1112                                         update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
1113                                 }
1114                         } else if ((item = string_list_lookup(renames2Dst, ren1_dst))) {
1115                                 ren2 = item->util;
1116                                 clean_merge = 0;
1117                                 ren2->processed = 1;
1118                                 output(o, 1, "CONFLICT (rename/rename): "
1119                                        "Rename %s->%s in %s. "
1120                                        "Rename %s->%s in %s",
1121                                        ren1_src, ren1_dst, branch1,
1122                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
1123                                 conflict_rename_rename_2to1(o, ren1, branch1, ren2, branch2);
1124                         } else
1125                                 try_merge = 1;
1127                         if (try_merge) {
1128                                 struct diff_filespec *one, *a, *b;
1129                                 src_other.path = (char *)ren1_src;
1131                                 one = ren1->pair->one;
1132                                 if (a_renames == renames1) {
1133                                         a = ren1->pair->two;
1134                                         b = &src_other;
1135                                 } else {
1136                                         b = ren1->pair->two;
1137                                         a = &src_other;
1138                                 }
1139                                 update_stages_and_entry(ren1_dst, ren1->dst_entry, one, a, b, 1);
1140                                 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
1141                                         setup_rename_df_conflict_info(RENAME_NORMAL,
1142                                                                       ren1->pair,
1143                                                                       NULL,
1144                                                                       branch1,
1145                                                                       NULL,
1146                                                                       ren1->dst_entry,
1147                                                                       NULL);
1148                                 }
1149                         }
1150                 }
1151         }
1152         string_list_clear(&a_by_dst, 0);
1153         string_list_clear(&b_by_dst, 0);
1155         return clean_merge;
1158 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1160         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1163 static int read_sha1_strbuf(const unsigned char *sha1, struct strbuf *dst)
1165         void *buf;
1166         enum object_type type;
1167         unsigned long size;
1168         buf = read_sha1_file(sha1, &type, &size);
1169         if (!buf)
1170                 return error("cannot read object %s", sha1_to_hex(sha1));
1171         if (type != OBJ_BLOB) {
1172                 free(buf);
1173                 return error("object %s is not a blob", sha1_to_hex(sha1));
1174         }
1175         strbuf_attach(dst, buf, size, size + 1);
1176         return 0;
1179 static int blob_unchanged(const unsigned char *o_sha,
1180                           const unsigned char *a_sha,
1181                           int renormalize, const char *path)
1183         struct strbuf o = STRBUF_INIT;
1184         struct strbuf a = STRBUF_INIT;
1185         int ret = 0; /* assume changed for safety */
1187         if (sha_eq(o_sha, a_sha))
1188                 return 1;
1189         if (!renormalize)
1190                 return 0;
1192         assert(o_sha && a_sha);
1193         if (read_sha1_strbuf(o_sha, &o) || read_sha1_strbuf(a_sha, &a))
1194                 goto error_return;
1195         /*
1196          * Note: binary | is used so that both renormalizations are
1197          * performed.  Comparison can be skipped if both files are
1198          * unchanged since their sha1s have already been compared.
1199          */
1200         if (renormalize_buffer(path, o.buf, o.len, &o) |
1201             renormalize_buffer(path, a.buf, o.len, &a))
1202                 ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
1204 error_return:
1205         strbuf_release(&o);
1206         strbuf_release(&a);
1207         return ret;
1210 static void handle_delete_modify(struct merge_options *o,
1211                                  const char *path,
1212                                  const char *new_path,
1213                                  unsigned char *a_sha, int a_mode,
1214                                  unsigned char *b_sha, int b_mode)
1216         if (!a_sha) {
1217                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1218                        "and modified in %s. Version %s of %s left in tree%s%s.",
1219                        path, o->branch1,
1220                        o->branch2, o->branch2, path,
1221                        path == new_path ? "" : " at ",
1222                        path == new_path ? "" : new_path);
1223                 update_file(o, 0, b_sha, b_mode, new_path);
1224         } else {
1225                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1226                        "and modified in %s. Version %s of %s left in tree%s%s.",
1227                        path, o->branch2,
1228                        o->branch1, o->branch1, path,
1229                        path == new_path ? "" : " at ",
1230                        path == new_path ? "" : new_path);
1231                 update_file(o, 0, a_sha, a_mode, new_path);
1232         }
1235 static int merge_content(struct merge_options *o,
1236                          const char *path,
1237                          unsigned char *o_sha, int o_mode,
1238                          unsigned char *a_sha, int a_mode,
1239                          unsigned char *b_sha, int b_mode,
1240                          const char *df_rename_conflict_branch)
1242         const char *reason = "content";
1243         struct merge_file_info mfi;
1244         struct diff_filespec one, a, b;
1245         struct stat st;
1246         unsigned df_conflict_remains = 0;
1248         if (!o_sha) {
1249                 reason = "add/add";
1250                 o_sha = (unsigned char *)null_sha1;
1251         }
1252         one.path = a.path = b.path = (char *)path;
1253         hashcpy(one.sha1, o_sha);
1254         one.mode = o_mode;
1255         hashcpy(a.sha1, a_sha);
1256         a.mode = a_mode;
1257         hashcpy(b.sha1, b_sha);
1258         b.mode = b_mode;
1260         mfi = merge_file(o, &one, &a, &b, o->branch1, o->branch2);
1261         if (df_rename_conflict_branch &&
1262             lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1263                 df_conflict_remains = 1;
1264         }
1266         if (mfi.clean && !df_conflict_remains &&
1267             sha_eq(mfi.sha, a_sha) && mfi.mode == a.mode)
1268                 output(o, 3, "Skipped %s (merged same as existing)", path);
1269         else
1270                 output(o, 2, "Auto-merging %s", path);
1272         if (!mfi.clean) {
1273                 if (S_ISGITLINK(mfi.mode))
1274                         reason = "submodule";
1275                 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1276                                 reason, path);
1277         }
1279         if (df_conflict_remains) {
1280                 const char *new_path;
1281                 update_file_flags(o, mfi.sha, mfi.mode, path,
1282                                   o->call_depth || mfi.clean, 0);
1283                 new_path = unique_path(o, path, df_rename_conflict_branch);
1284                 mfi.clean = 0;
1285                 output(o, 1, "Adding as %s instead", new_path);
1286                 update_file_flags(o, mfi.sha, mfi.mode, new_path, 0, 1);
1287         } else {
1288                 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1289         }
1290         return mfi.clean;
1294 /* Per entry merge function */
1295 static int process_entry(struct merge_options *o,
1296                          const char *path, struct stage_data *entry)
1298         /*
1299         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1300         print_index_entry("\tpath: ", entry);
1301         */
1302         int clean_merge = 1;
1303         int normalize = o->renormalize;
1304         unsigned o_mode = entry->stages[1].mode;
1305         unsigned a_mode = entry->stages[2].mode;
1306         unsigned b_mode = entry->stages[3].mode;
1307         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1308         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1309         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1311         if (entry->rename_df_conflict_info)
1312                 return 1; /* Such cases are handled elsewhere. */
1314         entry->processed = 1;
1315         if (o_sha && (!a_sha || !b_sha)) {
1316                 /* Case A: Deleted in one */
1317                 if ((!a_sha && !b_sha) ||
1318                     (!b_sha && blob_unchanged(o_sha, a_sha, normalize, path)) ||
1319                     (!a_sha && blob_unchanged(o_sha, b_sha, normalize, path))) {
1320                         /* Deleted in both or deleted in one and
1321                          * unchanged in the other */
1322                         if (a_sha)
1323                                 output(o, 2, "Removing %s", path);
1324                         /* do not touch working file if it did not exist */
1325                         remove_file(o, 1, path, !a_sha);
1326                 } else if (string_list_has_string(&o->current_directory_set,
1327                                                   path)) {
1328                         entry->processed = 0;
1329                         return 1; /* Assume clean until processed */
1330                 } else {
1331                         /* Deleted in one and changed in the other */
1332                         clean_merge = 0;
1333                         handle_delete_modify(o, path, path,
1334                                              a_sha, a_mode, b_sha, b_mode);
1335                 }
1337         } else if ((!o_sha && a_sha && !b_sha) ||
1338                    (!o_sha && !a_sha && b_sha)) {
1339                 /* Case B: Added in one. */
1340                 unsigned mode;
1341                 const unsigned char *sha;
1343                 if (a_sha) {
1344                         mode = a_mode;
1345                         sha = a_sha;
1346                 } else {
1347                         mode = b_mode;
1348                         sha = b_sha;
1349                 }
1350                 if (string_list_has_string(&o->current_directory_set, path)) {
1351                         /* Handle D->F conflicts after all subfiles */
1352                         entry->processed = 0;
1353                         return 1; /* Assume clean until processed */
1354                 } else {
1355                         output(o, 2, "Adding %s", path);
1356                         update_file(o, 1, sha, mode, path);
1357                 }
1358         } else if (a_sha && b_sha) {
1359                 /* Case C: Added in both (check for same permissions) and */
1360                 /* case D: Modified in both, but differently. */
1361                 clean_merge = merge_content(o, path,
1362                                             o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1363                                             NULL);
1364         } else if (!o_sha && !a_sha && !b_sha) {
1365                 /*
1366                  * this entry was deleted altogether. a_mode == 0 means
1367                  * we had that path and want to actively remove it.
1368                  */
1369                 remove_file(o, 1, path, !a_mode);
1370         } else
1371                 die("Fatal merge failure, shouldn't happen.");
1373         return clean_merge;
1376 /*
1377  * Per entry merge function for D/F (and/or rename) conflicts.  In the
1378  * cases we can cleanly resolve D/F conflicts, process_entry() can
1379  * clean out all the files below the directory for us.  All D/F
1380  * conflict cases must be handled here at the end to make sure any
1381  * directories that can be cleaned out, are.
1382  *
1383  * Some rename conflicts may also be handled here that don't necessarily
1384  * involve D/F conflicts, since the code to handle them is generic enough
1385  * to handle those rename conflicts with or without D/F conflicts also
1386  * being involved.
1387  */
1388 static int process_df_entry(struct merge_options *o,
1389                             const char *path, struct stage_data *entry)
1391         int clean_merge = 1;
1392         unsigned o_mode = entry->stages[1].mode;
1393         unsigned a_mode = entry->stages[2].mode;
1394         unsigned b_mode = entry->stages[3].mode;
1395         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1396         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1397         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1398         struct stat st;
1400         entry->processed = 1;
1401         if (entry->rename_df_conflict_info) {
1402                 struct rename_df_conflict_info *conflict_info = entry->rename_df_conflict_info;
1403                 char *src;
1404                 switch (conflict_info->rename_type) {
1405                 case RENAME_NORMAL:
1406                         clean_merge = merge_content(o, path,
1407                                                     o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
1408                                                     conflict_info->branch1);
1409                         break;
1410                 case RENAME_DELETE:
1411                         clean_merge = 0;
1412                         conflict_rename_delete(o, conflict_info->pair1,
1413                                                conflict_info->branch1,
1414                                                conflict_info->branch2);
1415                         break;
1416                 case RENAME_ONE_FILE_TO_TWO:
1417                         src = conflict_info->pair1->one->path;
1418                         clean_merge = 0;
1419                         output(o, 1, "CONFLICT (rename/rename): "
1420                                "Rename \"%s\"->\"%s\" in branch \"%s\" "
1421                                "rename \"%s\"->\"%s\" in \"%s\"%s",
1422                                src, conflict_info->pair1->two->path, conflict_info->branch1,
1423                                src, conflict_info->pair2->two->path, conflict_info->branch2,
1424                                o->call_depth ? " (left unresolved)" : "");
1425                         if (o->call_depth) {
1426                                 remove_file_from_cache(src);
1427                                 update_file(o, 0, conflict_info->pair1->one->sha1,
1428                                             conflict_info->pair1->one->mode, src);
1429                         }
1430                         conflict_rename_rename_1to2(o, conflict_info->pair1,
1431                                                     conflict_info->branch1,
1432                                                     conflict_info->pair2,
1433                                                     conflict_info->branch2);
1434                         conflict_info->dst_entry2->processed = 1;
1435                         break;
1436                 default:
1437                         entry->processed = 0;
1438                         break;
1439                 }
1440         } else if (o_sha && (!a_sha || !b_sha)) {
1441                 /* Modify/delete; deleted side may have put a directory in the way */
1442                 const char *new_path = path;
1443                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode))
1444                         new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
1445                 clean_merge = 0;
1446                 handle_delete_modify(o, path, new_path,
1447                                      a_sha, a_mode, b_sha, b_mode);
1448         } else if (!o_sha && !!a_sha != !!b_sha) {
1449                 /* directory -> (directory, file) */
1450                 const char *add_branch;
1451                 const char *other_branch;
1452                 unsigned mode;
1453                 const unsigned char *sha;
1454                 const char *conf;
1456                 if (a_sha) {
1457                         add_branch = o->branch1;
1458                         other_branch = o->branch2;
1459                         mode = a_mode;
1460                         sha = a_sha;
1461                         conf = "file/directory";
1462                 } else {
1463                         add_branch = o->branch2;
1464                         other_branch = o->branch1;
1465                         mode = b_mode;
1466                         sha = b_sha;
1467                         conf = "directory/file";
1468                 }
1469                 if (lstat(path, &st) == 0 && S_ISDIR(st.st_mode)) {
1470                         const char *new_path = unique_path(o, path, add_branch);
1471                         clean_merge = 0;
1472                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1473                                "Adding %s as %s",
1474                                conf, path, other_branch, path, new_path);
1475                         update_file(o, 0, sha, mode, new_path);
1476                 } else {
1477                         output(o, 2, "Adding %s", path);
1478                         update_file(o, 1, sha, mode, path);
1479                 }
1480         } else {
1481                 entry->processed = 0;
1482                 return 1; /* not handled; assume clean until processed */
1483         }
1485         return clean_merge;
1488 int merge_trees(struct merge_options *o,
1489                 struct tree *head,
1490                 struct tree *merge,
1491                 struct tree *common,
1492                 struct tree **result)
1494         int code, clean;
1496         if (o->subtree_shift) {
1497                 merge = shift_tree_object(head, merge, o->subtree_shift);
1498                 common = shift_tree_object(head, common, o->subtree_shift);
1499         }
1501         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1502                 output(o, 0, "Already up-to-date!");
1503                 *result = head;
1504                 return 1;
1505         }
1507         code = git_merge_trees(o->call_depth, common, head, merge);
1509         if (code != 0) {
1510                 if (show(o, 4) || o->call_depth)
1511                         die("merging of trees %s and %s failed",
1512                             sha1_to_hex(head->object.sha1),
1513                             sha1_to_hex(merge->object.sha1));
1514                 else
1515                         exit(128);
1516         }
1518         if (unmerged_cache()) {
1519                 struct string_list *entries, *re_head, *re_merge;
1520                 int i;
1521                 string_list_clear(&o->current_file_set, 1);
1522                 string_list_clear(&o->current_directory_set, 1);
1523                 get_files_dirs(o, head);
1524                 get_files_dirs(o, merge);
1526                 entries = get_unmerged();
1527                 make_room_for_directories_of_df_conflicts(o, entries);
1528                 re_head  = get_renames(o, head, common, head, merge, entries);
1529                 re_merge = get_renames(o, merge, common, head, merge, entries);
1530                 clean = process_renames(o, re_head, re_merge);
1531                 for (i = 0; i < entries->nr; i++) {
1532                         const char *path = entries->items[i].string;
1533                         struct stage_data *e = entries->items[i].util;
1534                         if (!e->processed
1535                                 && !process_entry(o, path, e))
1536                                 clean = 0;
1537                 }
1538                 for (i = 0; i < entries->nr; i++) {
1539                         const char *path = entries->items[i].string;
1540                         struct stage_data *e = entries->items[i].util;
1541                         if (!e->processed
1542                                 && !process_df_entry(o, path, e))
1543                                 clean = 0;
1544                 }
1545                 for (i = 0; i < entries->nr; i++) {
1546                         struct stage_data *e = entries->items[i].util;
1547                         if (!e->processed)
1548                                 die("Unprocessed path??? %s",
1549                                     entries->items[i].string);
1550                 }
1552                 string_list_clear(re_merge, 0);
1553                 string_list_clear(re_head, 0);
1554                 string_list_clear(entries, 1);
1556         }
1557         else
1558                 clean = 1;
1560         if (o->call_depth)
1561                 *result = write_tree_from_memory(o);
1563         return clean;
1566 static struct commit_list *reverse_commit_list(struct commit_list *list)
1568         struct commit_list *next = NULL, *current, *backup;
1569         for (current = list; current; current = backup) {
1570                 backup = current->next;
1571                 current->next = next;
1572                 next = current;
1573         }
1574         return next;
1577 /*
1578  * Merge the commits h1 and h2, return the resulting virtual
1579  * commit object and a flag indicating the cleanness of the merge.
1580  */
1581 int merge_recursive(struct merge_options *o,
1582                     struct commit *h1,
1583                     struct commit *h2,
1584                     struct commit_list *ca,
1585                     struct commit **result)
1587         struct commit_list *iter;
1588         struct commit *merged_common_ancestors;
1589         struct tree *mrtree = mrtree;
1590         int clean;
1592         if (show(o, 4)) {
1593                 output(o, 4, "Merging:");
1594                 output_commit_title(o, h1);
1595                 output_commit_title(o, h2);
1596         }
1598         if (!ca) {
1599                 ca = get_merge_bases(h1, h2, 1);
1600                 ca = reverse_commit_list(ca);
1601         }
1603         if (show(o, 5)) {
1604                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1605                 for (iter = ca; iter; iter = iter->next)
1606                         output_commit_title(o, iter->item);
1607         }
1609         merged_common_ancestors = pop_commit(&ca);
1610         if (merged_common_ancestors == NULL) {
1611                 /* if there is no common ancestor, make an empty tree */
1612                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1614                 tree->object.parsed = 1;
1615                 tree->object.type = OBJ_TREE;
1616                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1617                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1618         }
1620         for (iter = ca; iter; iter = iter->next) {
1621                 const char *saved_b1, *saved_b2;
1622                 o->call_depth++;
1623                 /*
1624                  * When the merge fails, the result contains files
1625                  * with conflict markers. The cleanness flag is
1626                  * ignored, it was never actually used, as result of
1627                  * merge_trees has always overwritten it: the committed
1628                  * "conflicts" were already resolved.
1629                  */
1630                 discard_cache();
1631                 saved_b1 = o->branch1;
1632                 saved_b2 = o->branch2;
1633                 o->branch1 = "Temporary merge branch 1";
1634                 o->branch2 = "Temporary merge branch 2";
1635                 merge_recursive(o, merged_common_ancestors, iter->item,
1636                                 NULL, &merged_common_ancestors);
1637                 o->branch1 = saved_b1;
1638                 o->branch2 = saved_b2;
1639                 o->call_depth--;
1641                 if (!merged_common_ancestors)
1642                         die("merge returned no commit");
1643         }
1645         discard_cache();
1646         if (!o->call_depth)
1647                 read_cache();
1649         o->ancestor = "merged common ancestors";
1650         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1651                             &mrtree);
1653         if (o->call_depth) {
1654                 *result = make_virtual_commit(mrtree, "merged tree");
1655                 commit_list_insert(h1, &(*result)->parents);
1656                 commit_list_insert(h2, &(*result)->parents->next);
1657         }
1658         flush_output(o);
1659         if (o->needed_rename_limit)
1660                 warning(rename_limit_advice, o->needed_rename_limit);
1661         return clean;
1664 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1666         struct object *object;
1668         object = deref_tag(parse_object(sha1), name, strlen(name));
1669         if (!object)
1670                 return NULL;
1671         if (object->type == OBJ_TREE)
1672                 return make_virtual_commit((struct tree*)object, name);
1673         if (object->type != OBJ_COMMIT)
1674                 return NULL;
1675         if (parse_commit((struct commit *)object))
1676                 return NULL;
1677         return (struct commit *)object;
1680 int merge_recursive_generic(struct merge_options *o,
1681                             const unsigned char *head,
1682                             const unsigned char *merge,
1683                             int num_base_list,
1684                             const unsigned char **base_list,
1685                             struct commit **result)
1687         int clean, index_fd;
1688         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1689         struct commit *head_commit = get_ref(head, o->branch1);
1690         struct commit *next_commit = get_ref(merge, o->branch2);
1691         struct commit_list *ca = NULL;
1693         if (base_list) {
1694                 int i;
1695                 for (i = 0; i < num_base_list; ++i) {
1696                         struct commit *base;
1697                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1698                                 return error("Could not parse object '%s'",
1699                                         sha1_to_hex(base_list[i]));
1700                         commit_list_insert(base, &ca);
1701                 }
1702         }
1704         index_fd = hold_locked_index(lock, 1);
1705         clean = merge_recursive(o, head_commit, next_commit, ca,
1706                         result);
1707         if (active_cache_changed &&
1708                         (write_cache(index_fd, active_cache, active_nr) ||
1709                          commit_locked_index(lock)))
1710                 return error("Unable to write index.");
1712         return clean ? 0 : 1;
1715 static int merge_recursive_config(const char *var, const char *value, void *cb)
1717         struct merge_options *o = cb;
1718         if (!strcasecmp(var, "merge.verbosity")) {
1719                 o->verbosity = git_config_int(var, value);
1720                 return 0;
1721         }
1722         if (!strcasecmp(var, "diff.renamelimit")) {
1723                 o->diff_rename_limit = git_config_int(var, value);
1724                 return 0;
1725         }
1726         if (!strcasecmp(var, "merge.renamelimit")) {
1727                 o->merge_rename_limit = git_config_int(var, value);
1728                 return 0;
1729         }
1730         return git_xmerge_config(var, value, cb);
1733 void init_merge_options(struct merge_options *o)
1735         memset(o, 0, sizeof(struct merge_options));
1736         o->verbosity = 2;
1737         o->buffer_output = 1;
1738         o->diff_rename_limit = -1;
1739         o->merge_rename_limit = -1;
1740         o->renormalize = 0;
1741         git_config(merge_recursive_config, o);
1742         if (getenv("GIT_MERGE_VERBOSITY"))
1743                 o->verbosity =
1744                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1745         if (o->verbosity >= 5)
1746                 o->buffer_output = 0;
1747         strbuf_init(&o->obuf, 0);
1748         memset(&o->current_file_set, 0, sizeof(struct string_list));
1749         o->current_file_set.strdup_strings = 1;
1750         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1751         o->current_directory_set.strdup_strings = 1;
1754 int parse_merge_opt(struct merge_options *o, const char *s)
1756         if (!s || !*s)
1757                 return -1;
1758         if (!strcmp(s, "ours"))
1759                 o->recursive_variant = MERGE_RECURSIVE_OURS;
1760         else if (!strcmp(s, "theirs"))
1761                 o->recursive_variant = MERGE_RECURSIVE_THEIRS;
1762         else if (!strcmp(s, "subtree"))
1763                 o->subtree_shift = "";
1764         else if (!prefixcmp(s, "subtree="))
1765                 o->subtree_shift = s + strlen("subtree=");
1766         else if (!strcmp(s, "patience"))
1767                 o->xdl_opts |= XDF_PATIENCE_DIFF;
1768         else if (!strcmp(s, "ignore-space-change"))
1769                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
1770         else if (!strcmp(s, "ignore-all-space"))
1771                 o->xdl_opts |= XDF_IGNORE_WHITESPACE;
1772         else if (!strcmp(s, "ignore-space-at-eol"))
1773                 o->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
1774         else if (!strcmp(s, "renormalize"))
1775                 o->renormalize = 1;
1776         else if (!strcmp(s, "no-renormalize"))
1777                 o->renormalize = 0;
1778         else if (!prefixcmp(s, "rename-threshold=")) {
1779                 const char *score = s + strlen("rename-threshold=");
1780                 if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
1781                         return -1;
1782         }
1783         else
1784                 return -1;
1785         return 0;