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[git.git] / builtin-merge-recursive.c
1 /*
2  * Recursive Merge algorithm stolen from git-merge-recursive.py by
3  * Fredrik Kuivinen.
4  * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5  */
6 #include "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
23 static int subtree_merge;
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27         unsigned char shifted[20];
29         /*
30          * NEEDSWORK: this limits the recursion depth to hardcoded
31          * value '2' to avoid excessive overhead.
32          */
33         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
34         if (!hashcmp(two->object.sha1, shifted))
35                 return two;
36         return lookup_tree(shifted);
37 }
39 /*
40  * A virtual commit has
41  * - (const char *)commit->util set to the name, and
42  * - *(int *)commit->object.sha1 set to the virtual id.
43  */
45 static unsigned commit_list_count(const struct commit_list *l)
46 {
47         unsigned c = 0;
48         for (; l; l = l->next )
49                 c++;
50         return c;
51 }
53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
54 {
55         struct commit *commit = xcalloc(1, sizeof(struct commit));
56         static unsigned virtual_id = 1;
57         commit->tree = tree;
58         commit->util = (void*)comment;
59         *(int*)commit->object.sha1 = virtual_id++;
60         /* avoid warnings */
61         commit->object.parsed = 1;
62         return commit;
63 }
65 /*
66  * Since we use get_tree_entry(), which does not put the read object into
67  * the object pool, we cannot rely on a == b.
68  */
69 static int sha_eq(const unsigned char *a, const unsigned char *b)
70 {
71         if (!a && !b)
72                 return 2;
73         return a && b && hashcmp(a, b) == 0;
74 }
76 /*
77  * Since we want to write the index eventually, we cannot reuse the index
78  * for these (temporary) data.
79  */
80 struct stage_data
81 {
82         struct
83         {
84                 unsigned mode;
85                 unsigned char sha[20];
86         } stages[4];
87         unsigned processed:1;
88 };
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int diff_rename_limit = -1;
96 static int merge_rename_limit = -1;
97 static int buffer_output = 1;
98 static struct strbuf obuf = STRBUF_INIT;
100 static int show(int v)
102         return (!call_depth && verbosity >= v) || verbosity >= 5;
105 static void flush_output(void)
107         if (obuf.len) {
108                 fputs(obuf.buf, stdout);
109                 strbuf_reset(&obuf);
110         }
113 static void output(int v, const char *fmt, ...)
115         int len;
116         va_list ap;
118         if (!show(v))
119                 return;
121         strbuf_grow(&obuf, call_depth * 2 + 2);
122         memset(obuf.buf + obuf.len, ' ', call_depth * 2);
123         strbuf_setlen(&obuf, obuf.len + call_depth * 2);
125         va_start(ap, fmt);
126         len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
127         va_end(ap);
129         if (len < 0)
130                 len = 0;
131         if (len >= strbuf_avail(&obuf)) {
132                 strbuf_grow(&obuf, len + 2);
133                 va_start(ap, fmt);
134                 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
135                 va_end(ap);
136                 if (len >= strbuf_avail(&obuf)) {
137                         die("this should not happen, your snprintf is broken");
138                 }
139         }
140         strbuf_setlen(&obuf, obuf.len + len);
141         strbuf_add(&obuf, "\n", 1);
142         if (!buffer_output)
143                 flush_output();
146 static void output_commit_title(struct commit *commit)
148         int i;
149         flush_output();
150         for (i = call_depth; i--;)
151                 fputs("  ", stdout);
152         if (commit->util)
153                 printf("virtual %s\n", (char *)commit->util);
154         else {
155                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
156                 if (parse_commit(commit) != 0)
157                         printf("(bad commit)\n");
158                 else {
159                         const char *s;
160                         int len;
161                         for (s = commit->buffer; *s; s++)
162                                 if (*s == '\n' && s[1] == '\n') {
163                                         s += 2;
164                                         break;
165                                 }
166                         for (len = 0; s[len] && '\n' != s[len]; len++)
167                                 ; /* do nothing */
168                         printf("%.*s\n", len, s);
169                 }
170         }
173 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
174                 const char *path, int stage, int refresh, int options)
176         struct cache_entry *ce;
177         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
178         if (!ce)
179                 return error("addinfo_cache failed for path '%s'", path);
180         return add_cache_entry(ce, options);
183 /*
184  * This is a global variable which is used in a number of places but
185  * only written to in the 'merge' function.
186  *
187  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
188  *                       don't update the working directory.
189  *               0    => Leave unmerged entries in the cache and update
190  *                       the working directory.
191  */
192 static int index_only = 0;
194 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
196         parse_tree(tree);
197         init_tree_desc(desc, tree->buffer, tree->size);
200 static int git_merge_trees(int index_only,
201                            struct tree *common,
202                            struct tree *head,
203                            struct tree *merge)
205         int rc;
206         struct tree_desc t[3];
207         struct unpack_trees_options opts;
209         memset(&opts, 0, sizeof(opts));
210         if (index_only)
211                 opts.index_only = 1;
212         else
213                 opts.update = 1;
214         opts.merge = 1;
215         opts.head_idx = 2;
216         opts.fn = threeway_merge;
217         opts.src_index = &the_index;
218         opts.dst_index = &the_index;
220         init_tree_desc_from_tree(t+0, common);
221         init_tree_desc_from_tree(t+1, head);
222         init_tree_desc_from_tree(t+2, merge);
224         rc = unpack_trees(3, t, &opts);
225         cache_tree_free(&active_cache_tree);
226         return rc;
229 struct tree *write_tree_from_memory(void)
231         struct tree *result = NULL;
233         if (unmerged_cache()) {
234                 int i;
235                 output(0, "There are unmerged index entries:");
236                 for (i = 0; i < active_nr; i++) {
237                         struct cache_entry *ce = active_cache[i];
238                         if (ce_stage(ce))
239                                 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
240                 }
241                 return NULL;
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)
261         int len = strlen(path);
262         char *newpath = xmalloc(baselen + len + 1);
263         memcpy(newpath, base, baselen);
264         memcpy(newpath + baselen, path, len);
265         newpath[baselen + len] = '\0';
267         if (S_ISDIR(mode))
268                 path_list_insert(newpath, &current_directory_set);
269         else
270                 path_list_insert(newpath, &current_file_set);
271         free(newpath);
273         return READ_TREE_RECURSIVE;
276 static int get_files_dirs(struct tree *tree)
278         int n;
279         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
280                 return 0;
281         n = current_file_set.nr + current_directory_set.nr;
282         return n;
285 /*
286  * Returns an index_entry instance which doesn't have to correspond to
287  * a real cache entry in Git's index.
288  */
289 static struct stage_data *insert_stage_data(const char *path,
290                 struct tree *o, struct tree *a, struct tree *b,
291                 struct path_list *entries)
293         struct path_list_item *item;
294         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
295         get_tree_entry(o->object.sha1, path,
296                         e->stages[1].sha, &e->stages[1].mode);
297         get_tree_entry(a->object.sha1, path,
298                         e->stages[2].sha, &e->stages[2].mode);
299         get_tree_entry(b->object.sha1, path,
300                         e->stages[3].sha, &e->stages[3].mode);
301         item = path_list_insert(path, entries);
302         item->util = e;
303         return e;
306 /*
307  * Create a dictionary mapping file names to stage_data objects. The
308  * dictionary contains one entry for every path with a non-zero stage entry.
309  */
310 static struct path_list *get_unmerged(void)
312         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
313         int i;
315         unmerged->strdup_paths = 1;
317         for (i = 0; i < active_nr; i++) {
318                 struct path_list_item *item;
319                 struct stage_data *e;
320                 struct cache_entry *ce = active_cache[i];
321                 if (!ce_stage(ce))
322                         continue;
324                 item = path_list_lookup(ce->name, unmerged);
325                 if (!item) {
326                         item = path_list_insert(ce->name, unmerged);
327                         item->util = xcalloc(1, sizeof(struct stage_data));
328                 }
329                 e = item->util;
330                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
331                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
332         }
334         return unmerged;
337 struct rename
339         struct diff_filepair *pair;
340         struct stage_data *src_entry;
341         struct stage_data *dst_entry;
342         unsigned processed:1;
343 };
345 /*
346  * Get information of all renames which occurred between 'o_tree' and
347  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
348  * 'b_tree') to be able to associate the correct cache entries with
349  * the rename information. 'tree' is always equal to either a_tree or b_tree.
350  */
351 static struct path_list *get_renames(struct tree *tree,
352                                         struct tree *o_tree,
353                                         struct tree *a_tree,
354                                         struct tree *b_tree,
355                                         struct path_list *entries)
357         int i;
358         struct path_list *renames;
359         struct diff_options opts;
361         renames = xcalloc(1, sizeof(struct path_list));
362         diff_setup(&opts);
363         DIFF_OPT_SET(&opts, RECURSIVE);
364         opts.detect_rename = DIFF_DETECT_RENAME;
365         opts.rename_limit = merge_rename_limit >= 0 ? merge_rename_limit :
366                             diff_rename_limit >= 0 ? diff_rename_limit :
367                             500;
368         opts.warn_on_too_large_rename = 1;
369         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
370         if (diff_setup_done(&opts) < 0)
371                 die("diff setup failed");
372         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
373         diffcore_std(&opts);
374         for (i = 0; i < diff_queued_diff.nr; ++i) {
375                 struct path_list_item *item;
376                 struct rename *re;
377                 struct diff_filepair *pair = diff_queued_diff.queue[i];
378                 if (pair->status != 'R') {
379                         diff_free_filepair(pair);
380                         continue;
381                 }
382                 re = xmalloc(sizeof(*re));
383                 re->processed = 0;
384                 re->pair = pair;
385                 item = path_list_lookup(re->pair->one->path, entries);
386                 if (!item)
387                         re->src_entry = insert_stage_data(re->pair->one->path,
388                                         o_tree, a_tree, b_tree, entries);
389                 else
390                         re->src_entry = item->util;
392                 item = path_list_lookup(re->pair->two->path, entries);
393                 if (!item)
394                         re->dst_entry = insert_stage_data(re->pair->two->path,
395                                         o_tree, a_tree, b_tree, entries);
396                 else
397                         re->dst_entry = item->util;
398                 item = path_list_insert(pair->one->path, renames);
399                 item->util = re;
400         }
401         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
402         diff_queued_diff.nr = 0;
403         diff_flush(&opts);
404         return renames;
407 static int update_stages(const char *path, struct diff_filespec *o,
408                          struct diff_filespec *a, struct diff_filespec *b,
409                          int clear)
411         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
412         if (clear)
413                 if (remove_file_from_cache(path))
414                         return -1;
415         if (o)
416                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
417                         return -1;
418         if (a)
419                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
420                         return -1;
421         if (b)
422                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
423                         return -1;
424         return 0;
427 static int remove_path(const char *name)
429         int ret;
430         char *slash, *dirs;
432         ret = unlink(name);
433         if (ret)
434                 return ret;
435         dirs = xstrdup(name);
436         while ((slash = strrchr(name, '/'))) {
437                 *slash = '\0';
438                 if (rmdir(name) != 0)
439                         break;
440         }
441         free(dirs);
442         return ret;
445 static int remove_file(int clean, const char *path, int no_wd)
447         int update_cache = index_only || clean;
448         int update_working_directory = !index_only && !no_wd;
450         if (update_cache) {
451                 if (remove_file_from_cache(path))
452                         return -1;
453         }
454         if (update_working_directory) {
455                 unlink(path);
456                 if (errno != ENOENT || errno != EISDIR)
457                         return -1;
458                 remove_path(path);
459         }
460         return 0;
463 static char *unique_path(const char *path, const char *branch)
465         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
466         int suffix = 0;
467         struct stat st;
468         char *p = newpath + strlen(path);
469         strcpy(newpath, path);
470         *(p++) = '~';
471         strcpy(p, branch);
472         for (; *p; ++p)
473                 if ('/' == *p)
474                         *p = '_';
475         while (path_list_has_path(&current_file_set, newpath) ||
476                path_list_has_path(&current_directory_set, newpath) ||
477                lstat(newpath, &st) == 0)
478                 sprintf(p, "_%d", suffix++);
480         path_list_insert(newpath, &current_file_set);
481         return newpath;
484 static int mkdir_p(const char *path, unsigned long mode)
486         /* path points to cache entries, so xstrdup before messing with it */
487         char *buf = xstrdup(path);
488         int result = safe_create_leading_directories(buf);
489         free(buf);
490         return result;
493 static void flush_buffer(int fd, const char *buf, unsigned long size)
495         while (size > 0) {
496                 long ret = write_in_full(fd, buf, size);
497                 if (ret < 0) {
498                         /* Ignore epipe */
499                         if (errno == EPIPE)
500                                 break;
501                         die("merge-recursive: %s", strerror(errno));
502                 } else if (!ret) {
503                         die("merge-recursive: disk full?");
504                 }
505                 size -= ret;
506                 buf += ret;
507         }
510 static int make_room_for_path(const char *path)
512         int status;
513         const char *msg = "failed to create path '%s'%s";
515         status = mkdir_p(path, 0777);
516         if (status) {
517                 if (status == -3) {
518                         /* something else exists */
519                         error(msg, path, ": perhaps a D/F conflict?");
520                         return -1;
521                 }
522                 die(msg, path, "");
523         }
525         /* Successful unlink is good.. */
526         if (!unlink(path))
527                 return 0;
528         /* .. and so is no existing file */
529         if (errno == ENOENT)
530                 return 0;
531         /* .. but not some other error (who really cares what?) */
532         return error(msg, path, ": perhaps a D/F conflict?");
535 static void update_file_flags(const unsigned char *sha,
536                               unsigned mode,
537                               const char *path,
538                               int update_cache,
539                               int update_wd)
541         if (index_only)
542                 update_wd = 0;
544         if (update_wd) {
545                 enum object_type type;
546                 void *buf;
547                 unsigned long size;
549                 if (S_ISGITLINK(mode))
550                         die("cannot read object %s '%s': It is a submodule!",
551                             sha1_to_hex(sha), path);
553                 buf = read_sha1_file(sha, &type, &size);
554                 if (!buf)
555                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
556                 if (type != OBJ_BLOB)
557                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
558                 if (S_ISREG(mode)) {
559                         struct strbuf strbuf;
560                         strbuf_init(&strbuf, 0);
561                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
562                                 free(buf);
563                                 size = strbuf.len;
564                                 buf = strbuf_detach(&strbuf, NULL);
565                         }
566                 }
568                 if (make_room_for_path(path) < 0) {
569                         update_wd = 0;
570                         free(buf);
571                         goto update_index;
572                 }
573                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
574                         int fd;
575                         if (mode & 0100)
576                                 mode = 0777;
577                         else
578                                 mode = 0666;
579                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
580                         if (fd < 0)
581                                 die("failed to open %s: %s", path, strerror(errno));
582                         flush_buffer(fd, buf, size);
583                         close(fd);
584                 } else if (S_ISLNK(mode)) {
585                         char *lnk = xmemdupz(buf, size);
586                         mkdir_p(path, 0777);
587                         unlink(path);
588                         symlink(lnk, path);
589                         free(lnk);
590                 } else
591                         die("do not know what to do with %06o %s '%s'",
592                             mode, sha1_to_hex(sha), path);
593                 free(buf);
594         }
595  update_index:
596         if (update_cache)
597                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
600 static void update_file(int clean,
601                         const unsigned char *sha,
602                         unsigned mode,
603                         const char *path)
605         update_file_flags(sha, mode, path, index_only || clean, !index_only);
608 /* Low level file merging, update and removal */
610 struct merge_file_info
612         unsigned char sha[20];
613         unsigned mode;
614         unsigned clean:1,
615                  merge:1;
616 };
618 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
620         unsigned long size;
621         enum object_type type;
623         if (!hashcmp(sha1, null_sha1)) {
624                 mm->ptr = xstrdup("");
625                 mm->size = 0;
626                 return;
627         }
629         mm->ptr = read_sha1_file(sha1, &type, &size);
630         if (!mm->ptr || type != OBJ_BLOB)
631                 die("unable to read blob object %s", sha1_to_hex(sha1));
632         mm->size = size;
635 static int merge_3way(mmbuffer_t *result_buf,
636                       struct diff_filespec *o,
637                       struct diff_filespec *a,
638                       struct diff_filespec *b,
639                       const char *branch1,
640                       const char *branch2)
642         mmfile_t orig, src1, src2;
643         char *name1, *name2;
644         int merge_status;
646         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
647         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
649         fill_mm(o->sha1, &orig);
650         fill_mm(a->sha1, &src1);
651         fill_mm(b->sha1, &src2);
653         merge_status = ll_merge(result_buf, a->path, &orig,
654                                 &src1, name1, &src2, name2,
655                                 index_only);
657         free(name1);
658         free(name2);
659         free(orig.ptr);
660         free(src1.ptr);
661         free(src2.ptr);
662         return merge_status;
665 static struct merge_file_info merge_file(struct diff_filespec *o,
666                 struct diff_filespec *a, struct diff_filespec *b,
667                 const char *branch1, const char *branch2)
669         struct merge_file_info result;
670         result.merge = 0;
671         result.clean = 1;
673         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
674                 result.clean = 0;
675                 if (S_ISREG(a->mode)) {
676                         result.mode = a->mode;
677                         hashcpy(result.sha, a->sha1);
678                 } else {
679                         result.mode = b->mode;
680                         hashcpy(result.sha, b->sha1);
681                 }
682         } else {
683                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
684                         result.merge = 1;
686                 /*
687                  * Merge modes
688                  */
689                 if (a->mode == b->mode || a->mode == o->mode)
690                         result.mode = b->mode;
691                 else {
692                         result.mode = a->mode;
693                         if (b->mode != o->mode) {
694                                 result.clean = 0;
695                                 result.merge = 1;
696                         }
697                 }
699                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, o->sha1))
700                         hashcpy(result.sha, b->sha1);
701                 else if (sha_eq(b->sha1, o->sha1))
702                         hashcpy(result.sha, a->sha1);
703                 else if (S_ISREG(a->mode)) {
704                         mmbuffer_t result_buf;
705                         int merge_status;
707                         merge_status = merge_3way(&result_buf, o, a, b,
708                                                   branch1, branch2);
710                         if ((merge_status < 0) || !result_buf.ptr)
711                                 die("Failed to execute internal merge");
713                         if (write_sha1_file(result_buf.ptr, result_buf.size,
714                                             blob_type, result.sha))
715                                 die("Unable to add %s to database",
716                                     a->path);
718                         free(result_buf.ptr);
719                         result.clean = (merge_status == 0);
720                 } else if (S_ISGITLINK(a->mode)) {
721                         result.clean = 0;
722                         hashcpy(result.sha, a->sha1);
723                 } else if (S_ISLNK(a->mode)) {
724                         hashcpy(result.sha, a->sha1);
726                         if (!sha_eq(a->sha1, b->sha1))
727                                 result.clean = 0;
728                 } else {
729                         die("unsupported object type in the tree");
730                 }
731         }
733         return result;
736 static void conflict_rename_rename(struct rename *ren1,
737                                    const char *branch1,
738                                    struct rename *ren2,
739                                    const char *branch2)
741         char *del[2];
742         int delp = 0;
743         const char *ren1_dst = ren1->pair->two->path;
744         const char *ren2_dst = ren2->pair->two->path;
745         const char *dst_name1 = ren1_dst;
746         const char *dst_name2 = ren2_dst;
747         if (path_list_has_path(&current_directory_set, ren1_dst)) {
748                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
749                 output(1, "%s is a directory in %s added as %s instead",
750                        ren1_dst, branch2, dst_name1);
751                 remove_file(0, ren1_dst, 0);
752         }
753         if (path_list_has_path(&current_directory_set, ren2_dst)) {
754                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
755                 output(1, "%s is a directory in %s added as %s instead",
756                        ren2_dst, branch1, dst_name2);
757                 remove_file(0, ren2_dst, 0);
758         }
759         if (index_only) {
760                 remove_file_from_cache(dst_name1);
761                 remove_file_from_cache(dst_name2);
762                 /*
763                  * Uncomment to leave the conflicting names in the resulting tree
764                  *
765                  * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
766                  * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
767                  */
768         } else {
769                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
770                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
771         }
772         while (delp--)
773                 free(del[delp]);
776 static void conflict_rename_dir(struct rename *ren1,
777                                 const char *branch1)
779         char *new_path = unique_path(ren1->pair->two->path, branch1);
780         output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
781         remove_file(0, ren1->pair->two->path, 0);
782         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
783         free(new_path);
786 static void conflict_rename_rename_2(struct rename *ren1,
787                                      const char *branch1,
788                                      struct rename *ren2,
789                                      const char *branch2)
791         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
792         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
793         output(1, "Renamed %s to %s and %s to %s instead",
794                ren1->pair->one->path, new_path1,
795                ren2->pair->one->path, new_path2);
796         remove_file(0, ren1->pair->two->path, 0);
797         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
798         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
799         free(new_path2);
800         free(new_path1);
803 static int process_renames(struct path_list *a_renames,
804                            struct path_list *b_renames,
805                            const char *a_branch,
806                            const char *b_branch)
808         int clean_merge = 1, i, j;
809         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
810         const struct rename *sre;
812         for (i = 0; i < a_renames->nr; i++) {
813                 sre = a_renames->items[i].util;
814                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
815                         = sre->dst_entry;
816         }
817         for (i = 0; i < b_renames->nr; i++) {
818                 sre = b_renames->items[i].util;
819                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
820                         = sre->dst_entry;
821         }
823         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
824                 int compare;
825                 char *src;
826                 struct path_list *renames1, *renames2, *renames2Dst;
827                 struct rename *ren1 = NULL, *ren2 = NULL;
828                 const char *branch1, *branch2;
829                 const char *ren1_src, *ren1_dst;
831                 if (i >= a_renames->nr) {
832                         compare = 1;
833                         ren2 = b_renames->items[j++].util;
834                 } else if (j >= b_renames->nr) {
835                         compare = -1;
836                         ren1 = a_renames->items[i++].util;
837                 } else {
838                         compare = strcmp(a_renames->items[i].path,
839                                         b_renames->items[j].path);
840                         if (compare <= 0)
841                                 ren1 = a_renames->items[i++].util;
842                         if (compare >= 0)
843                                 ren2 = b_renames->items[j++].util;
844                 }
846                 /* TODO: refactor, so that 1/2 are not needed */
847                 if (ren1) {
848                         renames1 = a_renames;
849                         renames2 = b_renames;
850                         renames2Dst = &b_by_dst;
851                         branch1 = a_branch;
852                         branch2 = b_branch;
853                 } else {
854                         struct rename *tmp;
855                         renames1 = b_renames;
856                         renames2 = a_renames;
857                         renames2Dst = &a_by_dst;
858                         branch1 = b_branch;
859                         branch2 = a_branch;
860                         tmp = ren2;
861                         ren2 = ren1;
862                         ren1 = tmp;
863                 }
864                 src = ren1->pair->one->path;
866                 ren1->dst_entry->processed = 1;
867                 ren1->src_entry->processed = 1;
869                 if (ren1->processed)
870                         continue;
871                 ren1->processed = 1;
873                 ren1_src = ren1->pair->one->path;
874                 ren1_dst = ren1->pair->two->path;
876                 if (ren2) {
877                         const char *ren2_src = ren2->pair->one->path;
878                         const char *ren2_dst = ren2->pair->two->path;
879                         /* Renamed in 1 and renamed in 2 */
880                         if (strcmp(ren1_src, ren2_src) != 0)
881                                 die("ren1.src != ren2.src");
882                         ren2->dst_entry->processed = 1;
883                         ren2->processed = 1;
884                         if (strcmp(ren1_dst, ren2_dst) != 0) {
885                                 clean_merge = 0;
886                                 output(1, "CONFLICT (rename/rename): "
887                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
888                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
889                                        src, ren1_dst, branch1,
890                                        src, ren2_dst, branch2,
891                                        index_only ? " (left unresolved)": "");
892                                 if (index_only) {
893                                         remove_file_from_cache(src);
894                                         update_file(0, ren1->pair->one->sha1,
895                                                     ren1->pair->one->mode, src);
896                                 }
897                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
898                         } else {
899                                 struct merge_file_info mfi;
900                                 remove_file(1, ren1_src, 1);
901                                 mfi = merge_file(ren1->pair->one,
902                                                  ren1->pair->two,
903                                                  ren2->pair->two,
904                                                  branch1,
905                                                  branch2);
906                                 if (mfi.merge || !mfi.clean)
907                                         output(1, "Renamed %s->%s", src, ren1_dst);
909                                 if (mfi.merge)
910                                         output(2, "Auto-merged %s", ren1_dst);
912                                 if (!mfi.clean) {
913                                         output(1, "CONFLICT (content): merge conflict in %s",
914                                                ren1_dst);
915                                         clean_merge = 0;
917                                         if (!index_only)
918                                                 update_stages(ren1_dst,
919                                                               ren1->pair->one,
920                                                               ren1->pair->two,
921                                                               ren2->pair->two,
922                                                               1 /* clear */);
923                                 }
924                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
925                         }
926                 } else {
927                         /* Renamed in 1, maybe changed in 2 */
928                         struct path_list_item *item;
929                         /* we only use sha1 and mode of these */
930                         struct diff_filespec src_other, dst_other;
931                         int try_merge, stage = a_renames == renames1 ? 3: 2;
933                         remove_file(1, ren1_src, index_only || stage == 3);
935                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
936                         src_other.mode = ren1->src_entry->stages[stage].mode;
937                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
938                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
940                         try_merge = 0;
942                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
943                                 clean_merge = 0;
944                                 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
945                                        " directory %s added in %s",
946                                        ren1_src, ren1_dst, branch1,
947                                        ren1_dst, branch2);
948                                 conflict_rename_dir(ren1, branch1);
949                         } else if (sha_eq(src_other.sha1, null_sha1)) {
950                                 clean_merge = 0;
951                                 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
952                                        "and deleted in %s",
953                                        ren1_src, ren1_dst, branch1,
954                                        branch2);
955                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
956                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
957                                 const char *new_path;
958                                 clean_merge = 0;
959                                 try_merge = 1;
960                                 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
961                                        "%s added in %s",
962                                        ren1_src, ren1_dst, branch1,
963                                        ren1_dst, branch2);
964                                 new_path = unique_path(ren1_dst, branch2);
965                                 output(1, "Added as %s instead", new_path);
966                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
967                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
968                                 ren2 = item->util;
969                                 clean_merge = 0;
970                                 ren2->processed = 1;
971                                 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
972                                        "Renamed %s->%s in %s",
973                                        ren1_src, ren1_dst, branch1,
974                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
975                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
976                         } else
977                                 try_merge = 1;
979                         if (try_merge) {
980                                 struct diff_filespec *o, *a, *b;
981                                 struct merge_file_info mfi;
982                                 src_other.path = (char *)ren1_src;
984                                 o = ren1->pair->one;
985                                 if (a_renames == renames1) {
986                                         a = ren1->pair->two;
987                                         b = &src_other;
988                                 } else {
989                                         b = ren1->pair->two;
990                                         a = &src_other;
991                                 }
992                                 mfi = merge_file(o, a, b,
993                                                 a_branch, b_branch);
995                                 if (mfi.clean &&
996                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
997                                     mfi.mode == ren1->pair->two->mode)
998                                         /*
999                                          * This messaged is part of
1000                                          * t6022 test. If you change
1001                                          * it update the test too.
1002                                          */
1003                                         output(3, "Skipped %s (merged same as existing)", ren1_dst);
1004                                 else {
1005                                         if (mfi.merge || !mfi.clean)
1006                                                 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1007                                         if (mfi.merge)
1008                                                 output(2, "Auto-merged %s", ren1_dst);
1009                                         if (!mfi.clean) {
1010                                                 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1011                                                        ren1_dst);
1012                                                 clean_merge = 0;
1014                                                 if (!index_only)
1015                                                         update_stages(ren1_dst,
1016                                                                       o, a, b, 1);
1017                                         }
1018                                         update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1019                                 }
1020                         }
1021                 }
1022         }
1023         path_list_clear(&a_by_dst, 0);
1024         path_list_clear(&b_by_dst, 0);
1026         return clean_merge;
1029 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1031         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1034 /* Per entry merge function */
1035 static int process_entry(const char *path, struct stage_data *entry,
1036                          const char *branch1,
1037                          const char *branch2)
1039         /*
1040         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1041         print_index_entry("\tpath: ", entry);
1042         */
1043         int clean_merge = 1;
1044         unsigned o_mode = entry->stages[1].mode;
1045         unsigned a_mode = entry->stages[2].mode;
1046         unsigned b_mode = entry->stages[3].mode;
1047         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1048         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1049         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1051         if (o_sha && (!a_sha || !b_sha)) {
1052                 /* Case A: Deleted in one */
1053                 if ((!a_sha && !b_sha) ||
1054                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1055                     (!a_sha && sha_eq(b_sha, o_sha))) {
1056                         /* Deleted in both or deleted in one and
1057                          * unchanged in the other */
1058                         if (a_sha)
1059                                 output(2, "Removed %s", path);
1060                         /* do not touch working file if it did not exist */
1061                         remove_file(1, path, !a_sha);
1062                 } else {
1063                         /* Deleted in one and changed in the other */
1064                         clean_merge = 0;
1065                         if (!a_sha) {
1066                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1067                                        "and modified in %s. Version %s of %s left in tree.",
1068                                        path, branch1,
1069                                        branch2, branch2, path);
1070                                 update_file(0, b_sha, b_mode, path);
1071                         } else {
1072                                 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1073                                        "and modified in %s. Version %s of %s left in tree.",
1074                                        path, branch2,
1075                                        branch1, branch1, path);
1076                                 update_file(0, a_sha, a_mode, path);
1077                         }
1078                 }
1080         } else if ((!o_sha && a_sha && !b_sha) ||
1081                    (!o_sha && !a_sha && b_sha)) {
1082                 /* Case B: Added in one. */
1083                 const char *add_branch;
1084                 const char *other_branch;
1085                 unsigned mode;
1086                 const unsigned char *sha;
1087                 const char *conf;
1089                 if (a_sha) {
1090                         add_branch = branch1;
1091                         other_branch = branch2;
1092                         mode = a_mode;
1093                         sha = a_sha;
1094                         conf = "file/directory";
1095                 } else {
1096                         add_branch = branch2;
1097                         other_branch = branch1;
1098                         mode = b_mode;
1099                         sha = b_sha;
1100                         conf = "directory/file";
1101                 }
1102                 if (path_list_has_path(&current_directory_set, path)) {
1103                         const char *new_path = unique_path(path, add_branch);
1104                         clean_merge = 0;
1105                         output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1106                                "Added %s as %s",
1107                                conf, path, other_branch, path, new_path);
1108                         remove_file(0, path, 0);
1109                         update_file(0, sha, mode, new_path);
1110                 } else {
1111                         output(2, "Added %s", path);
1112                         update_file(1, sha, mode, path);
1113                 }
1114         } else if (a_sha && b_sha) {
1115                 /* Case C: Added in both (check for same permissions) and */
1116                 /* case D: Modified in both, but differently. */
1117                 const char *reason = "content";
1118                 struct merge_file_info mfi;
1119                 struct diff_filespec o, a, b;
1121                 if (!o_sha) {
1122                         reason = "add/add";
1123                         o_sha = (unsigned char *)null_sha1;
1124                 }
1125                 output(2, "Auto-merged %s", path);
1126                 o.path = a.path = b.path = (char *)path;
1127                 hashcpy(o.sha1, o_sha);
1128                 o.mode = o_mode;
1129                 hashcpy(a.sha1, a_sha);
1130                 a.mode = a_mode;
1131                 hashcpy(b.sha1, b_sha);
1132                 b.mode = b_mode;
1134                 mfi = merge_file(&o, &a, &b,
1135                                  branch1, branch2);
1137                 clean_merge = mfi.clean;
1138                 if (mfi.clean)
1139                         update_file(1, mfi.sha, mfi.mode, path);
1140                 else if (S_ISGITLINK(mfi.mode))
1141                         output(1, "CONFLICT (submodule): Merge conflict in %s "
1142                                "- needs %s", path, sha1_to_hex(b.sha1));
1143                 else {
1144                         output(1, "CONFLICT (%s): Merge conflict in %s",
1145                                         reason, path);
1147                         if (index_only)
1148                                 update_file(0, mfi.sha, mfi.mode, path);
1149                         else
1150                                 update_file_flags(mfi.sha, mfi.mode, path,
1151                                               0 /* update_cache */, 1 /* update_working_directory */);
1152                 }
1153         } else if (!o_sha && !a_sha && !b_sha) {
1154                 /*
1155                  * this entry was deleted altogether. a_mode == 0 means
1156                  * we had that path and want to actively remove it.
1157                  */
1158                 remove_file(1, path, !a_mode);
1159         } else
1160                 die("Fatal merge failure, shouldn't happen.");
1162         return clean_merge;
1165 int merge_trees(struct tree *head,
1166                 struct tree *merge,
1167                 struct tree *common,
1168                 const char *branch1,
1169                 const char *branch2,
1170                 struct tree **result)
1172         int code, clean;
1174         if (subtree_merge) {
1175                 merge = shift_tree_object(head, merge);
1176                 common = shift_tree_object(head, common);
1177         }
1179         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1180                 output(0, "Already uptodate!");
1181                 *result = head;
1182                 return 1;
1183         }
1185         code = git_merge_trees(index_only, common, head, merge);
1187         if (code != 0)
1188                 die("merging of trees %s and %s failed",
1189                     sha1_to_hex(head->object.sha1),
1190                     sha1_to_hex(merge->object.sha1));
1192         if (unmerged_cache()) {
1193                 struct path_list *entries, *re_head, *re_merge;
1194                 int i;
1195                 path_list_clear(&current_file_set, 1);
1196                 path_list_clear(&current_directory_set, 1);
1197                 get_files_dirs(head);
1198                 get_files_dirs(merge);
1200                 entries = get_unmerged();
1201                 re_head  = get_renames(head, common, head, merge, entries);
1202                 re_merge = get_renames(merge, common, head, merge, entries);
1203                 clean = process_renames(re_head, re_merge,
1204                                 branch1, branch2);
1205                 for (i = 0; i < entries->nr; i++) {
1206                         const char *path = entries->items[i].path;
1207                         struct stage_data *e = entries->items[i].util;
1208                         if (!e->processed
1209                                 && !process_entry(path, e, branch1, branch2))
1210                                 clean = 0;
1211                 }
1213                 path_list_clear(re_merge, 0);
1214                 path_list_clear(re_head, 0);
1215                 path_list_clear(entries, 1);
1217         }
1218         else
1219                 clean = 1;
1221         if (index_only)
1222                 *result = write_tree_from_memory();
1224         return clean;
1227 static struct commit_list *reverse_commit_list(struct commit_list *list)
1229         struct commit_list *next = NULL, *current, *backup;
1230         for (current = list; current; current = backup) {
1231                 backup = current->next;
1232                 current->next = next;
1233                 next = current;
1234         }
1235         return next;
1238 /*
1239  * Merge the commits h1 and h2, return the resulting virtual
1240  * commit object and a flag indicating the cleanness of the merge.
1241  */
1242 int merge_recursive(struct commit *h1,
1243                     struct commit *h2,
1244                     const char *branch1,
1245                     const char *branch2,
1246                     struct commit_list *ca,
1247                     struct commit **result)
1249         struct commit_list *iter;
1250         struct commit *merged_common_ancestors;
1251         struct tree *mrtree = mrtree;
1252         int clean;
1254         if (show(4)) {
1255                 output(4, "Merging:");
1256                 output_commit_title(h1);
1257                 output_commit_title(h2);
1258         }
1260         if (!ca) {
1261                 ca = get_merge_bases(h1, h2, 1);
1262                 ca = reverse_commit_list(ca);
1263         }
1265         if (show(5)) {
1266                 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1267                 for (iter = ca; iter; iter = iter->next)
1268                         output_commit_title(iter->item);
1269         }
1271         merged_common_ancestors = pop_commit(&ca);
1272         if (merged_common_ancestors == NULL) {
1273                 /* if there is no common ancestor, make an empty tree */
1274                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1276                 tree->object.parsed = 1;
1277                 tree->object.type = OBJ_TREE;
1278                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1279                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1280         }
1282         for (iter = ca; iter; iter = iter->next) {
1283                 call_depth++;
1284                 /*
1285                  * When the merge fails, the result contains files
1286                  * with conflict markers. The cleanness flag is
1287                  * ignored, it was never actually used, as result of
1288                  * merge_trees has always overwritten it: the committed
1289                  * "conflicts" were already resolved.
1290                  */
1291                 discard_cache();
1292                 merge_recursive(merged_common_ancestors, iter->item,
1293                                 "Temporary merge branch 1",
1294                                 "Temporary merge branch 2",
1295                                 NULL,
1296                                 &merged_common_ancestors);
1297                 call_depth--;
1299                 if (!merged_common_ancestors)
1300                         die("merge returned no commit");
1301         }
1303         discard_cache();
1304         if (!call_depth) {
1305                 read_cache();
1306                 index_only = 0;
1307         } else
1308                 index_only = 1;
1310         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1311                             branch1, branch2, &mrtree);
1313         if (index_only) {
1314                 *result = make_virtual_commit(mrtree, "merged tree");
1315                 commit_list_insert(h1, &(*result)->parents);
1316                 commit_list_insert(h2, &(*result)->parents->next);
1317         }
1318         flush_output();
1319         return clean;
1322 static const char *better_branch_name(const char *branch)
1324         static char githead_env[8 + 40 + 1];
1325         char *name;
1327         if (strlen(branch) != 40)
1328                 return branch;
1329         sprintf(githead_env, "GITHEAD_%s", branch);
1330         name = getenv(githead_env);
1331         return name ? name : branch;
1334 static struct commit *get_ref(const char *ref)
1336         unsigned char sha1[20];
1337         struct object *object;
1339         if (get_sha1(ref, sha1))
1340                 die("Could not resolve ref '%s'", ref);
1341         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1342         if (!object)
1343                 return NULL;
1344         if (object->type == OBJ_TREE)
1345                 return make_virtual_commit((struct tree*)object,
1346                         better_branch_name(ref));
1347         if (object->type != OBJ_COMMIT)
1348                 return NULL;
1349         if (parse_commit((struct commit *)object))
1350                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1351         return (struct commit *)object;
1354 static int merge_config(const char *var, const char *value, void *cb)
1356         if (!strcasecmp(var, "merge.verbosity")) {
1357                 verbosity = git_config_int(var, value);
1358                 return 0;
1359         }
1360         if (!strcasecmp(var, "diff.renamelimit")) {
1361                 diff_rename_limit = git_config_int(var, value);
1362                 return 0;
1363         }
1364         if (!strcasecmp(var, "merge.renamelimit")) {
1365                 merge_rename_limit = git_config_int(var, value);
1366                 return 0;
1367         }
1368         return git_default_config(var, value, cb);
1371 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1373         static const char *bases[20];
1374         static unsigned bases_count = 0;
1375         int i, clean;
1376         const char *branch1, *branch2;
1377         struct commit *result, *h1, *h2;
1378         struct commit_list *ca = NULL;
1379         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1380         int index_fd;
1382         if (argv[0]) {
1383                 int namelen = strlen(argv[0]);
1384                 if (8 < namelen &&
1385                     !strcmp(argv[0] + namelen - 8, "-subtree"))
1386                         subtree_merge = 1;
1387         }
1389         git_config(merge_config, NULL);
1390         if (getenv("GIT_MERGE_VERBOSITY"))
1391                 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1393         if (argc < 4)
1394                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1396         for (i = 1; i < argc; ++i) {
1397                 if (!strcmp(argv[i], "--"))
1398                         break;
1399                 if (bases_count < sizeof(bases)/sizeof(*bases))
1400                         bases[bases_count++] = argv[i];
1401         }
1402         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1403                 die("Not handling anything other than two heads merge.");
1404         if (verbosity >= 5)
1405                 buffer_output = 0;
1407         branch1 = argv[++i];
1408         branch2 = argv[++i];
1410         h1 = get_ref(branch1);
1411         h2 = get_ref(branch2);
1413         branch1 = better_branch_name(branch1);
1414         branch2 = better_branch_name(branch2);
1416         if (show(3))
1417                 printf("Merging %s with %s\n", branch1, branch2);
1419         index_fd = hold_locked_index(lock, 1);
1421         for (i = 0; i < bases_count; i++) {
1422                 struct commit *ancestor = get_ref(bases[i]);
1423                 ca = commit_list_insert(ancestor, &ca);
1424         }
1425         clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1427         if (active_cache_changed &&
1428             (write_cache(index_fd, active_cache, active_nr) ||
1429              commit_locked_index(lock)))
1430                         die ("unable to write %s", get_index_file());
1432         return clean ? 0: 1;