Code

Merge git://repo.or.cz/git-gui
[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 "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "string-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22 #include "dir.h"
24 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
25 {
26         unsigned char shifted[20];
28         /*
29          * NEEDSWORK: this limits the recursion depth to hardcoded
30          * value '2' to avoid excessive overhead.
31          */
32         shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
33         if (!hashcmp(two->object.sha1, shifted))
34                 return two;
35         return lookup_tree(shifted);
36 }
38 /*
39  * A virtual commit has (const char *)commit->util set to the name.
40  */
42 struct commit *make_virtual_commit(struct tree *tree, const char *comment)
43 {
44         struct commit *commit = xcalloc(1, sizeof(struct commit));
45         commit->tree = tree;
46         commit->util = (void*)comment;
47         /* avoid warnings */
48         commit->object.parsed = 1;
49         return commit;
50 }
52 /*
53  * Since we use get_tree_entry(), which does not put the read object into
54  * the object pool, we cannot rely on a == b.
55  */
56 static int sha_eq(const unsigned char *a, const unsigned char *b)
57 {
58         if (!a && !b)
59                 return 2;
60         return a && b && hashcmp(a, b) == 0;
61 }
63 /*
64  * Since we want to write the index eventually, we cannot reuse the index
65  * for these (temporary) data.
66  */
67 struct stage_data
68 {
69         struct
70         {
71                 unsigned mode;
72                 unsigned char sha[20];
73         } stages[4];
74         unsigned processed:1;
75 };
77 static int show(struct merge_options *o, int v)
78 {
79         return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
80 }
82 static void flush_output(struct merge_options *o)
83 {
84         if (o->obuf.len) {
85                 fputs(o->obuf.buf, stdout);
86                 strbuf_reset(&o->obuf);
87         }
88 }
90 static void output(struct merge_options *o, int v, const char *fmt, ...)
91 {
92         int len;
93         va_list ap;
95         if (!show(o, v))
96                 return;
98         strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
99         memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
100         strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
102         va_start(ap, fmt);
103         len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
104         va_end(ap);
106         if (len < 0)
107                 len = 0;
108         if (len >= strbuf_avail(&o->obuf)) {
109                 strbuf_grow(&o->obuf, len + 2);
110                 va_start(ap, fmt);
111                 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
112                 va_end(ap);
113                 if (len >= strbuf_avail(&o->obuf)) {
114                         die("this should not happen, your snprintf is broken");
115                 }
116         }
117         strbuf_setlen(&o->obuf, o->obuf.len + len);
118         strbuf_add(&o->obuf, "\n", 1);
119         if (!o->buffer_output)
120                 flush_output(o);
123 static void output_commit_title(struct merge_options *o, struct commit *commit)
125         int i;
126         flush_output(o);
127         for (i = o->call_depth; i--;)
128                 fputs("  ", stdout);
129         if (commit->util)
130                 printf("virtual %s\n", (char *)commit->util);
131         else {
132                 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
133                 if (parse_commit(commit) != 0)
134                         printf("(bad commit)\n");
135                 else {
136                         const char *s;
137                         int len;
138                         for (s = commit->buffer; *s; s++)
139                                 if (*s == '\n' && s[1] == '\n') {
140                                         s += 2;
141                                         break;
142                                 }
143                         for (len = 0; s[len] && '\n' != s[len]; len++)
144                                 ; /* do nothing */
145                         printf("%.*s\n", len, s);
146                 }
147         }
150 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
151                 const char *path, int stage, int refresh, int options)
153         struct cache_entry *ce;
154         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
155         if (!ce)
156                 return error("addinfo_cache failed for path '%s'", path);
157         return add_cache_entry(ce, options);
160 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
162         parse_tree(tree);
163         init_tree_desc(desc, tree->buffer, tree->size);
166 static int git_merge_trees(int index_only,
167                            struct tree *common,
168                            struct tree *head,
169                            struct tree *merge)
171         int rc;
172         struct tree_desc t[3];
173         struct unpack_trees_options opts;
175         memset(&opts, 0, sizeof(opts));
176         if (index_only)
177                 opts.index_only = 1;
178         else
179                 opts.update = 1;
180         opts.merge = 1;
181         opts.head_idx = 2;
182         opts.fn = threeway_merge;
183         opts.src_index = &the_index;
184         opts.dst_index = &the_index;
186         init_tree_desc_from_tree(t+0, common);
187         init_tree_desc_from_tree(t+1, head);
188         init_tree_desc_from_tree(t+2, merge);
190         rc = unpack_trees(3, t, &opts);
191         cache_tree_free(&active_cache_tree);
192         return rc;
195 struct tree *write_tree_from_memory(struct merge_options *o)
197         struct tree *result = NULL;
199         if (unmerged_cache()) {
200                 int i;
201                 output(o, 0, "There are unmerged index entries:");
202                 for (i = 0; i < active_nr; i++) {
203                         struct cache_entry *ce = active_cache[i];
204                         if (ce_stage(ce))
205                                 output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
206                 }
207                 return NULL;
208         }
210         if (!active_cache_tree)
211                 active_cache_tree = cache_tree();
213         if (!cache_tree_fully_valid(active_cache_tree) &&
214             cache_tree_update(active_cache_tree,
215                               active_cache, active_nr, 0, 0) < 0)
216                 die("error building trees");
218         result = lookup_tree(active_cache_tree->sha1);
220         return result;
223 static int save_files_dirs(const unsigned char *sha1,
224                 const char *base, int baselen, const char *path,
225                 unsigned int mode, int stage, void *context)
227         int len = strlen(path);
228         char *newpath = xmalloc(baselen + len + 1);
229         struct merge_options *o = context;
231         memcpy(newpath, base, baselen);
232         memcpy(newpath + baselen, path, len);
233         newpath[baselen + len] = '\0';
235         if (S_ISDIR(mode))
236                 string_list_insert(newpath, &o->current_directory_set);
237         else
238                 string_list_insert(newpath, &o->current_file_set);
239         free(newpath);
241         return READ_TREE_RECURSIVE;
244 static int get_files_dirs(struct merge_options *o, struct tree *tree)
246         int n;
247         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
248                 return 0;
249         n = o->current_file_set.nr + o->current_directory_set.nr;
250         return n;
253 /*
254  * Returns an index_entry instance which doesn't have to correspond to
255  * a real cache entry in Git's index.
256  */
257 static struct stage_data *insert_stage_data(const char *path,
258                 struct tree *o, struct tree *a, struct tree *b,
259                 struct string_list *entries)
261         struct string_list_item *item;
262         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
263         get_tree_entry(o->object.sha1, path,
264                         e->stages[1].sha, &e->stages[1].mode);
265         get_tree_entry(a->object.sha1, path,
266                         e->stages[2].sha, &e->stages[2].mode);
267         get_tree_entry(b->object.sha1, path,
268                         e->stages[3].sha, &e->stages[3].mode);
269         item = string_list_insert(path, entries);
270         item->util = e;
271         return e;
274 /*
275  * Create a dictionary mapping file names to stage_data objects. The
276  * dictionary contains one entry for every path with a non-zero stage entry.
277  */
278 static struct string_list *get_unmerged(void)
280         struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
281         int i;
283         unmerged->strdup_strings = 1;
285         for (i = 0; i < active_nr; i++) {
286                 struct string_list_item *item;
287                 struct stage_data *e;
288                 struct cache_entry *ce = active_cache[i];
289                 if (!ce_stage(ce))
290                         continue;
292                 item = string_list_lookup(ce->name, unmerged);
293                 if (!item) {
294                         item = string_list_insert(ce->name, unmerged);
295                         item->util = xcalloc(1, sizeof(struct stage_data));
296                 }
297                 e = item->util;
298                 e->stages[ce_stage(ce)].mode = ce->ce_mode;
299                 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
300         }
302         return unmerged;
305 struct rename
307         struct diff_filepair *pair;
308         struct stage_data *src_entry;
309         struct stage_data *dst_entry;
310         unsigned processed:1;
311 };
313 /*
314  * Get information of all renames which occurred between 'o_tree' and
315  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
316  * 'b_tree') to be able to associate the correct cache entries with
317  * the rename information. 'tree' is always equal to either a_tree or b_tree.
318  */
319 static struct string_list *get_renames(struct merge_options *o,
320                                        struct tree *tree,
321                                        struct tree *o_tree,
322                                        struct tree *a_tree,
323                                        struct tree *b_tree,
324                                        struct string_list *entries)
326         int i;
327         struct string_list *renames;
328         struct diff_options opts;
330         renames = xcalloc(1, sizeof(struct string_list));
331         diff_setup(&opts);
332         DIFF_OPT_SET(&opts, RECURSIVE);
333         opts.detect_rename = DIFF_DETECT_RENAME;
334         opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
335                             o->diff_rename_limit >= 0 ? o->diff_rename_limit :
336                             500;
337         opts.warn_on_too_large_rename = 1;
338         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
339         if (diff_setup_done(&opts) < 0)
340                 die("diff setup failed");
341         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
342         diffcore_std(&opts);
343         for (i = 0; i < diff_queued_diff.nr; ++i) {
344                 struct string_list_item *item;
345                 struct rename *re;
346                 struct diff_filepair *pair = diff_queued_diff.queue[i];
347                 if (pair->status != 'R') {
348                         diff_free_filepair(pair);
349                         continue;
350                 }
351                 re = xmalloc(sizeof(*re));
352                 re->processed = 0;
353                 re->pair = pair;
354                 item = string_list_lookup(re->pair->one->path, entries);
355                 if (!item)
356                         re->src_entry = insert_stage_data(re->pair->one->path,
357                                         o_tree, a_tree, b_tree, entries);
358                 else
359                         re->src_entry = item->util;
361                 item = string_list_lookup(re->pair->two->path, entries);
362                 if (!item)
363                         re->dst_entry = insert_stage_data(re->pair->two->path,
364                                         o_tree, a_tree, b_tree, entries);
365                 else
366                         re->dst_entry = item->util;
367                 item = string_list_insert(pair->one->path, renames);
368                 item->util = re;
369         }
370         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
371         diff_queued_diff.nr = 0;
372         diff_flush(&opts);
373         return renames;
376 static int update_stages(const char *path, struct diff_filespec *o,
377                          struct diff_filespec *a, struct diff_filespec *b,
378                          int clear)
380         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
381         if (clear)
382                 if (remove_file_from_cache(path))
383                         return -1;
384         if (o)
385                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
386                         return -1;
387         if (a)
388                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
389                         return -1;
390         if (b)
391                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
392                         return -1;
393         return 0;
396 static int remove_file(struct merge_options *o, int clean,
397                        const char *path, int no_wd)
399         int update_cache = o->call_depth || clean;
400         int update_working_directory = !o->call_depth && !no_wd;
402         if (update_cache) {
403                 if (remove_file_from_cache(path))
404                         return -1;
405         }
406         if (update_working_directory) {
407                 if (remove_path(path) && errno != ENOENT)
408                         return -1;
409         }
410         return 0;
413 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
415         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
416         int suffix = 0;
417         struct stat st;
418         char *p = newpath + strlen(path);
419         strcpy(newpath, path);
420         *(p++) = '~';
421         strcpy(p, branch);
422         for (; *p; ++p)
423                 if ('/' == *p)
424                         *p = '_';
425         while (string_list_has_string(&o->current_file_set, newpath) ||
426                string_list_has_string(&o->current_directory_set, newpath) ||
427                lstat(newpath, &st) == 0)
428                 sprintf(p, "_%d", suffix++);
430         string_list_insert(newpath, &o->current_file_set);
431         return newpath;
434 static void flush_buffer(int fd, const char *buf, unsigned long size)
436         while (size > 0) {
437                 long ret = write_in_full(fd, buf, size);
438                 if (ret < 0) {
439                         /* Ignore epipe */
440                         if (errno == EPIPE)
441                                 break;
442                         die("merge-recursive: %s", strerror(errno));
443                 } else if (!ret) {
444                         die("merge-recursive: disk full?");
445                 }
446                 size -= ret;
447                 buf += ret;
448         }
451 static int make_room_for_path(const char *path)
453         int status;
454         const char *msg = "failed to create path '%s'%s";
456         status = safe_create_leading_directories_const(path);
457         if (status) {
458                 if (status == -3) {
459                         /* something else exists */
460                         error(msg, path, ": perhaps a D/F conflict?");
461                         return -1;
462                 }
463                 die(msg, path, "");
464         }
466         /* Successful unlink is good.. */
467         if (!unlink(path))
468                 return 0;
469         /* .. and so is no existing file */
470         if (errno == ENOENT)
471                 return 0;
472         /* .. but not some other error (who really cares what?) */
473         return error(msg, path, ": perhaps a D/F conflict?");
476 static void update_file_flags(struct merge_options *o,
477                               const unsigned char *sha,
478                               unsigned mode,
479                               const char *path,
480                               int update_cache,
481                               int update_wd)
483         if (o->call_depth)
484                 update_wd = 0;
486         if (update_wd) {
487                 enum object_type type;
488                 void *buf;
489                 unsigned long size;
491                 if (S_ISGITLINK(mode))
492                         die("cannot read object %s '%s': It is a submodule!",
493                             sha1_to_hex(sha), path);
495                 buf = read_sha1_file(sha, &type, &size);
496                 if (!buf)
497                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
498                 if (type != OBJ_BLOB)
499                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
500                 if (S_ISREG(mode)) {
501                         struct strbuf strbuf = STRBUF_INIT;
502                         if (convert_to_working_tree(path, buf, size, &strbuf)) {
503                                 free(buf);
504                                 size = strbuf.len;
505                                 buf = strbuf_detach(&strbuf, NULL);
506                         }
507                 }
509                 if (make_room_for_path(path) < 0) {
510                         update_wd = 0;
511                         free(buf);
512                         goto update_index;
513                 }
514                 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
515                         int fd;
516                         if (mode & 0100)
517                                 mode = 0777;
518                         else
519                                 mode = 0666;
520                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
521                         if (fd < 0)
522                                 die("failed to open %s: %s", path, strerror(errno));
523                         flush_buffer(fd, buf, size);
524                         close(fd);
525                 } else if (S_ISLNK(mode)) {
526                         char *lnk = xmemdupz(buf, size);
527                         safe_create_leading_directories_const(path);
528                         unlink(path);
529                         symlink(lnk, path);
530                         free(lnk);
531                 } else
532                         die("do not know what to do with %06o %s '%s'",
533                             mode, sha1_to_hex(sha), path);
534                 free(buf);
535         }
536  update_index:
537         if (update_cache)
538                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
541 static void update_file(struct merge_options *o,
542                         int clean,
543                         const unsigned char *sha,
544                         unsigned mode,
545                         const char *path)
547         update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
550 /* Low level file merging, update and removal */
552 struct merge_file_info
554         unsigned char sha[20];
555         unsigned mode;
556         unsigned clean:1,
557                  merge:1;
558 };
560 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
562         unsigned long size;
563         enum object_type type;
565         if (!hashcmp(sha1, null_sha1)) {
566                 mm->ptr = xstrdup("");
567                 mm->size = 0;
568                 return;
569         }
571         mm->ptr = read_sha1_file(sha1, &type, &size);
572         if (!mm->ptr || type != OBJ_BLOB)
573                 die("unable to read blob object %s", sha1_to_hex(sha1));
574         mm->size = size;
577 static int merge_3way(struct merge_options *o,
578                       mmbuffer_t *result_buf,
579                       struct diff_filespec *one,
580                       struct diff_filespec *a,
581                       struct diff_filespec *b,
582                       const char *branch1,
583                       const char *branch2)
585         mmfile_t orig, src1, src2;
586         char *name1, *name2;
587         int merge_status;
589         name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
590         name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
592         fill_mm(one->sha1, &orig);
593         fill_mm(a->sha1, &src1);
594         fill_mm(b->sha1, &src2);
596         merge_status = ll_merge(result_buf, a->path, &orig,
597                                 &src1, name1, &src2, name2,
598                                 o->call_depth);
600         free(name1);
601         free(name2);
602         free(orig.ptr);
603         free(src1.ptr);
604         free(src2.ptr);
605         return merge_status;
608 static struct merge_file_info merge_file(struct merge_options *o,
609                                          struct diff_filespec *one,
610                                          struct diff_filespec *a,
611                                          struct diff_filespec *b,
612                                          const char *branch1,
613                                          const char *branch2)
615         struct merge_file_info result;
616         result.merge = 0;
617         result.clean = 1;
619         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
620                 result.clean = 0;
621                 if (S_ISREG(a->mode)) {
622                         result.mode = a->mode;
623                         hashcpy(result.sha, a->sha1);
624                 } else {
625                         result.mode = b->mode;
626                         hashcpy(result.sha, b->sha1);
627                 }
628         } else {
629                 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
630                         result.merge = 1;
632                 /*
633                  * Merge modes
634                  */
635                 if (a->mode == b->mode || a->mode == one->mode)
636                         result.mode = b->mode;
637                 else {
638                         result.mode = a->mode;
639                         if (b->mode != one->mode) {
640                                 result.clean = 0;
641                                 result.merge = 1;
642                         }
643                 }
645                 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
646                         hashcpy(result.sha, b->sha1);
647                 else if (sha_eq(b->sha1, one->sha1))
648                         hashcpy(result.sha, a->sha1);
649                 else if (S_ISREG(a->mode)) {
650                         mmbuffer_t result_buf;
651                         int merge_status;
653                         merge_status = merge_3way(o, &result_buf, one, a, b,
654                                                   branch1, branch2);
656                         if ((merge_status < 0) || !result_buf.ptr)
657                                 die("Failed to execute internal merge");
659                         if (write_sha1_file(result_buf.ptr, result_buf.size,
660                                             blob_type, result.sha))
661                                 die("Unable to add %s to database",
662                                     a->path);
664                         free(result_buf.ptr);
665                         result.clean = (merge_status == 0);
666                 } else if (S_ISGITLINK(a->mode)) {
667                         result.clean = 0;
668                         hashcpy(result.sha, a->sha1);
669                 } else if (S_ISLNK(a->mode)) {
670                         hashcpy(result.sha, a->sha1);
672                         if (!sha_eq(a->sha1, b->sha1))
673                                 result.clean = 0;
674                 } else {
675                         die("unsupported object type in the tree");
676                 }
677         }
679         return result;
682 static void conflict_rename_rename(struct merge_options *o,
683                                    struct rename *ren1,
684                                    const char *branch1,
685                                    struct rename *ren2,
686                                    const char *branch2)
688         char *del[2];
689         int delp = 0;
690         const char *ren1_dst = ren1->pair->two->path;
691         const char *ren2_dst = ren2->pair->two->path;
692         const char *dst_name1 = ren1_dst;
693         const char *dst_name2 = ren2_dst;
694         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
695                 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
696                 output(o, 1, "%s is a directory in %s adding as %s instead",
697                        ren1_dst, branch2, dst_name1);
698                 remove_file(o, 0, ren1_dst, 0);
699         }
700         if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
701                 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
702                 output(o, 1, "%s is a directory in %s adding as %s instead",
703                        ren2_dst, branch1, dst_name2);
704                 remove_file(o, 0, ren2_dst, 0);
705         }
706         if (o->call_depth) {
707                 remove_file_from_cache(dst_name1);
708                 remove_file_from_cache(dst_name2);
709                 /*
710                  * Uncomment to leave the conflicting names in the resulting tree
711                  *
712                  * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
713                  * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
714                  */
715         } else {
716                 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
717                 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
718         }
719         while (delp--)
720                 free(del[delp]);
723 static void conflict_rename_dir(struct merge_options *o,
724                                 struct rename *ren1,
725                                 const char *branch1)
727         char *new_path = unique_path(o, ren1->pair->two->path, branch1);
728         output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
729         remove_file(o, 0, ren1->pair->two->path, 0);
730         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
731         free(new_path);
734 static void conflict_rename_rename_2(struct merge_options *o,
735                                      struct rename *ren1,
736                                      const char *branch1,
737                                      struct rename *ren2,
738                                      const char *branch2)
740         char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
741         char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
742         output(o, 1, "Renaming %s to %s and %s to %s instead",
743                ren1->pair->one->path, new_path1,
744                ren2->pair->one->path, new_path2);
745         remove_file(o, 0, ren1->pair->two->path, 0);
746         update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
747         update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
748         free(new_path2);
749         free(new_path1);
752 static int process_renames(struct merge_options *o,
753                            struct string_list *a_renames,
754                            struct string_list *b_renames)
756         int clean_merge = 1, i, j;
757         struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
758         const struct rename *sre;
760         for (i = 0; i < a_renames->nr; i++) {
761                 sre = a_renames->items[i].util;
762                 string_list_insert(sre->pair->two->path, &a_by_dst)->util
763                         = sre->dst_entry;
764         }
765         for (i = 0; i < b_renames->nr; i++) {
766                 sre = b_renames->items[i].util;
767                 string_list_insert(sre->pair->two->path, &b_by_dst)->util
768                         = sre->dst_entry;
769         }
771         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
772                 int compare;
773                 char *src;
774                 struct string_list *renames1, *renames2, *renames2Dst;
775                 struct rename *ren1 = NULL, *ren2 = NULL;
776                 const char *branch1, *branch2;
777                 const char *ren1_src, *ren1_dst;
779                 if (i >= a_renames->nr) {
780                         compare = 1;
781                         ren2 = b_renames->items[j++].util;
782                 } else if (j >= b_renames->nr) {
783                         compare = -1;
784                         ren1 = a_renames->items[i++].util;
785                 } else {
786                         compare = strcmp(a_renames->items[i].string,
787                                         b_renames->items[j].string);
788                         if (compare <= 0)
789                                 ren1 = a_renames->items[i++].util;
790                         if (compare >= 0)
791                                 ren2 = b_renames->items[j++].util;
792                 }
794                 /* TODO: refactor, so that 1/2 are not needed */
795                 if (ren1) {
796                         renames1 = a_renames;
797                         renames2 = b_renames;
798                         renames2Dst = &b_by_dst;
799                         branch1 = o->branch1;
800                         branch2 = o->branch2;
801                 } else {
802                         struct rename *tmp;
803                         renames1 = b_renames;
804                         renames2 = a_renames;
805                         renames2Dst = &a_by_dst;
806                         branch1 = o->branch2;
807                         branch2 = o->branch1;
808                         tmp = ren2;
809                         ren2 = ren1;
810                         ren1 = tmp;
811                 }
812                 src = ren1->pair->one->path;
814                 ren1->dst_entry->processed = 1;
815                 ren1->src_entry->processed = 1;
817                 if (ren1->processed)
818                         continue;
819                 ren1->processed = 1;
821                 ren1_src = ren1->pair->one->path;
822                 ren1_dst = ren1->pair->two->path;
824                 if (ren2) {
825                         const char *ren2_src = ren2->pair->one->path;
826                         const char *ren2_dst = ren2->pair->two->path;
827                         /* Renamed in 1 and renamed in 2 */
828                         if (strcmp(ren1_src, ren2_src) != 0)
829                                 die("ren1.src != ren2.src");
830                         ren2->dst_entry->processed = 1;
831                         ren2->processed = 1;
832                         if (strcmp(ren1_dst, ren2_dst) != 0) {
833                                 clean_merge = 0;
834                                 output(o, 1, "CONFLICT (rename/rename): "
835                                        "Rename \"%s\"->\"%s\" in branch \"%s\" "
836                                        "rename \"%s\"->\"%s\" in \"%s\"%s",
837                                        src, ren1_dst, branch1,
838                                        src, ren2_dst, branch2,
839                                        o->call_depth ? " (left unresolved)": "");
840                                 if (o->call_depth) {
841                                         remove_file_from_cache(src);
842                                         update_file(o, 0, ren1->pair->one->sha1,
843                                                     ren1->pair->one->mode, src);
844                                 }
845                                 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
846                         } else {
847                                 struct merge_file_info mfi;
848                                 remove_file(o, 1, ren1_src, 1);
849                                 mfi = merge_file(o,
850                                                  ren1->pair->one,
851                                                  ren1->pair->two,
852                                                  ren2->pair->two,
853                                                  branch1,
854                                                  branch2);
855                                 if (mfi.merge || !mfi.clean)
856                                         output(o, 1, "Renaming %s->%s", src, ren1_dst);
858                                 if (mfi.merge)
859                                         output(o, 2, "Auto-merging %s", ren1_dst);
861                                 if (!mfi.clean) {
862                                         output(o, 1, "CONFLICT (content): merge conflict in %s",
863                                                ren1_dst);
864                                         clean_merge = 0;
866                                         if (!o->call_depth)
867                                                 update_stages(ren1_dst,
868                                                               ren1->pair->one,
869                                                               ren1->pair->two,
870                                                               ren2->pair->two,
871                                                               1 /* clear */);
872                                 }
873                                 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
874                         }
875                 } else {
876                         /* Renamed in 1, maybe changed in 2 */
877                         struct string_list_item *item;
878                         /* we only use sha1 and mode of these */
879                         struct diff_filespec src_other, dst_other;
880                         int try_merge, stage = a_renames == renames1 ? 3: 2;
882                         remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
884                         hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
885                         src_other.mode = ren1->src_entry->stages[stage].mode;
886                         hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
887                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
889                         try_merge = 0;
891                         if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
892                                 clean_merge = 0;
893                                 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
894                                        " directory %s added in %s",
895                                        ren1_src, ren1_dst, branch1,
896                                        ren1_dst, branch2);
897                                 conflict_rename_dir(o, ren1, branch1);
898                         } else if (sha_eq(src_other.sha1, null_sha1)) {
899                                 clean_merge = 0;
900                                 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
901                                        "and deleted in %s",
902                                        ren1_src, ren1_dst, branch1,
903                                        branch2);
904                                 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
905                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
906                                 const char *new_path;
907                                 clean_merge = 0;
908                                 try_merge = 1;
909                                 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
910                                        "%s added in %s",
911                                        ren1_src, ren1_dst, branch1,
912                                        ren1_dst, branch2);
913                                 new_path = unique_path(o, ren1_dst, branch2);
914                                 output(o, 1, "Adding as %s instead", new_path);
915                                 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
916                         } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
917                                 ren2 = item->util;
918                                 clean_merge = 0;
919                                 ren2->processed = 1;
920                                 output(o, 1, "CONFLICT (rename/rename): "
921                                        "Rename %s->%s in %s. "
922                                        "Rename %s->%s in %s",
923                                        ren1_src, ren1_dst, branch1,
924                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
925                                 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
926                         } else
927                                 try_merge = 1;
929                         if (try_merge) {
930                                 struct diff_filespec *one, *a, *b;
931                                 struct merge_file_info mfi;
932                                 src_other.path = (char *)ren1_src;
934                                 one = ren1->pair->one;
935                                 if (a_renames == renames1) {
936                                         a = ren1->pair->two;
937                                         b = &src_other;
938                                 } else {
939                                         b = ren1->pair->two;
940                                         a = &src_other;
941                                 }
942                                 mfi = merge_file(o, one, a, b,
943                                                 o->branch1, o->branch2);
945                                 if (mfi.clean &&
946                                     sha_eq(mfi.sha, ren1->pair->two->sha1) &&
947                                     mfi.mode == ren1->pair->two->mode)
948                                         /*
949                                          * This messaged is part of
950                                          * t6022 test. If you change
951                                          * it update the test too.
952                                          */
953                                         output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
954                                 else {
955                                         if (mfi.merge || !mfi.clean)
956                                                 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
957                                         if (mfi.merge)
958                                                 output(o, 2, "Auto-merging %s", ren1_dst);
959                                         if (!mfi.clean) {
960                                                 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
961                                                        ren1_dst);
962                                                 clean_merge = 0;
964                                                 if (!o->call_depth)
965                                                         update_stages(ren1_dst,
966                                                                       one, a, b, 1);
967                                         }
968                                         update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
969                                 }
970                         }
971                 }
972         }
973         string_list_clear(&a_by_dst, 0);
974         string_list_clear(&b_by_dst, 0);
976         return clean_merge;
979 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
981         return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
984 /* Per entry merge function */
985 static int process_entry(struct merge_options *o,
986                          const char *path, struct stage_data *entry)
988         /*
989         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
990         print_index_entry("\tpath: ", entry);
991         */
992         int clean_merge = 1;
993         unsigned o_mode = entry->stages[1].mode;
994         unsigned a_mode = entry->stages[2].mode;
995         unsigned b_mode = entry->stages[3].mode;
996         unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
997         unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
998         unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1000         if (o_sha && (!a_sha || !b_sha)) {
1001                 /* Case A: Deleted in one */
1002                 if ((!a_sha && !b_sha) ||
1003                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1004                     (!a_sha && sha_eq(b_sha, o_sha))) {
1005                         /* Deleted in both or deleted in one and
1006                          * unchanged in the other */
1007                         if (a_sha)
1008                                 output(o, 2, "Removing %s", path);
1009                         /* do not touch working file if it did not exist */
1010                         remove_file(o, 1, path, !a_sha);
1011                 } else {
1012                         /* Deleted in one and changed in the other */
1013                         clean_merge = 0;
1014                         if (!a_sha) {
1015                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1016                                        "and modified in %s. Version %s of %s left in tree.",
1017                                        path, o->branch1,
1018                                        o->branch2, o->branch2, path);
1019                                 update_file(o, 0, b_sha, b_mode, path);
1020                         } else {
1021                                 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1022                                        "and modified in %s. Version %s of %s left in tree.",
1023                                        path, o->branch2,
1024                                        o->branch1, o->branch1, path);
1025                                 update_file(o, 0, a_sha, a_mode, path);
1026                         }
1027                 }
1029         } else if ((!o_sha && a_sha && !b_sha) ||
1030                    (!o_sha && !a_sha && b_sha)) {
1031                 /* Case B: Added in one. */
1032                 const char *add_branch;
1033                 const char *other_branch;
1034                 unsigned mode;
1035                 const unsigned char *sha;
1036                 const char *conf;
1038                 if (a_sha) {
1039                         add_branch = o->branch1;
1040                         other_branch = o->branch2;
1041                         mode = a_mode;
1042                         sha = a_sha;
1043                         conf = "file/directory";
1044                 } else {
1045                         add_branch = o->branch2;
1046                         other_branch = o->branch1;
1047                         mode = b_mode;
1048                         sha = b_sha;
1049                         conf = "directory/file";
1050                 }
1051                 if (string_list_has_string(&o->current_directory_set, path)) {
1052                         const char *new_path = unique_path(o, path, add_branch);
1053                         clean_merge = 0;
1054                         output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1055                                "Adding %s as %s",
1056                                conf, path, other_branch, path, new_path);
1057                         remove_file(o, 0, path, 0);
1058                         update_file(o, 0, sha, mode, new_path);
1059                 } else {
1060                         output(o, 2, "Adding %s", path);
1061                         update_file(o, 1, sha, mode, path);
1062                 }
1063         } else if (a_sha && b_sha) {
1064                 /* Case C: Added in both (check for same permissions) and */
1065                 /* case D: Modified in both, but differently. */
1066                 const char *reason = "content";
1067                 struct merge_file_info mfi;
1068                 struct diff_filespec one, a, b;
1070                 if (!o_sha) {
1071                         reason = "add/add";
1072                         o_sha = (unsigned char *)null_sha1;
1073                 }
1074                 output(o, 2, "Auto-merging %s", path);
1075                 one.path = a.path = b.path = (char *)path;
1076                 hashcpy(one.sha1, o_sha);
1077                 one.mode = o_mode;
1078                 hashcpy(a.sha1, a_sha);
1079                 a.mode = a_mode;
1080                 hashcpy(b.sha1, b_sha);
1081                 b.mode = b_mode;
1083                 mfi = merge_file(o, &one, &a, &b,
1084                                  o->branch1, o->branch2);
1086                 clean_merge = mfi.clean;
1087                 if (mfi.clean)
1088                         update_file(o, 1, mfi.sha, mfi.mode, path);
1089                 else if (S_ISGITLINK(mfi.mode))
1090                         output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
1091                                "- needs %s", path, sha1_to_hex(b.sha1));
1092                 else {
1093                         output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1094                                         reason, path);
1096                         if (o->call_depth)
1097                                 update_file(o, 0, mfi.sha, mfi.mode, path);
1098                         else
1099                                 update_file_flags(o, mfi.sha, mfi.mode, path,
1100                                               0 /* update_cache */, 1 /* update_working_directory */);
1101                 }
1102         } else if (!o_sha && !a_sha && !b_sha) {
1103                 /*
1104                  * this entry was deleted altogether. a_mode == 0 means
1105                  * we had that path and want to actively remove it.
1106                  */
1107                 remove_file(o, 1, path, !a_mode);
1108         } else
1109                 die("Fatal merge failure, shouldn't happen.");
1111         return clean_merge;
1114 int merge_trees(struct merge_options *o,
1115                 struct tree *head,
1116                 struct tree *merge,
1117                 struct tree *common,
1118                 struct tree **result)
1120         int code, clean;
1122         if (o->subtree_merge) {
1123                 merge = shift_tree_object(head, merge);
1124                 common = shift_tree_object(head, common);
1125         }
1127         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1128                 output(o, 0, "Already uptodate!");
1129                 *result = head;
1130                 return 1;
1131         }
1133         code = git_merge_trees(o->call_depth, common, head, merge);
1135         if (code != 0)
1136                 die("merging of trees %s and %s failed",
1137                     sha1_to_hex(head->object.sha1),
1138                     sha1_to_hex(merge->object.sha1));
1140         if (unmerged_cache()) {
1141                 struct string_list *entries, *re_head, *re_merge;
1142                 int i;
1143                 string_list_clear(&o->current_file_set, 1);
1144                 string_list_clear(&o->current_directory_set, 1);
1145                 get_files_dirs(o, head);
1146                 get_files_dirs(o, merge);
1148                 entries = get_unmerged();
1149                 re_head  = get_renames(o, head, common, head, merge, entries);
1150                 re_merge = get_renames(o, merge, common, head, merge, entries);
1151                 clean = process_renames(o, re_head, re_merge);
1152                 for (i = 0; i < entries->nr; i++) {
1153                         const char *path = entries->items[i].string;
1154                         struct stage_data *e = entries->items[i].util;
1155                         if (!e->processed
1156                                 && !process_entry(o, path, e))
1157                                 clean = 0;
1158                 }
1160                 string_list_clear(re_merge, 0);
1161                 string_list_clear(re_head, 0);
1162                 string_list_clear(entries, 1);
1164         }
1165         else
1166                 clean = 1;
1168         if (o->call_depth)
1169                 *result = write_tree_from_memory(o);
1171         return clean;
1174 static struct commit_list *reverse_commit_list(struct commit_list *list)
1176         struct commit_list *next = NULL, *current, *backup;
1177         for (current = list; current; current = backup) {
1178                 backup = current->next;
1179                 current->next = next;
1180                 next = current;
1181         }
1182         return next;
1185 /*
1186  * Merge the commits h1 and h2, return the resulting virtual
1187  * commit object and a flag indicating the cleanness of the merge.
1188  */
1189 int merge_recursive(struct merge_options *o,
1190                     struct commit *h1,
1191                     struct commit *h2,
1192                     struct commit_list *ca,
1193                     struct commit **result)
1195         struct commit_list *iter;
1196         struct commit *merged_common_ancestors;
1197         struct tree *mrtree = mrtree;
1198         int clean;
1200         if (show(o, 4)) {
1201                 output(o, 4, "Merging:");
1202                 output_commit_title(o, h1);
1203                 output_commit_title(o, h2);
1204         }
1206         if (!ca) {
1207                 ca = get_merge_bases(h1, h2, 1);
1208                 ca = reverse_commit_list(ca);
1209         }
1211         if (show(o, 5)) {
1212                 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1213                 for (iter = ca; iter; iter = iter->next)
1214                         output_commit_title(o, iter->item);
1215         }
1217         merged_common_ancestors = pop_commit(&ca);
1218         if (merged_common_ancestors == NULL) {
1219                 /* if there is no common ancestor, make an empty tree */
1220                 struct tree *tree = xcalloc(1, sizeof(struct tree));
1222                 tree->object.parsed = 1;
1223                 tree->object.type = OBJ_TREE;
1224                 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1225                 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1226         }
1228         for (iter = ca; iter; iter = iter->next) {
1229                 const char *saved_b1, *saved_b2;
1230                 o->call_depth++;
1231                 /*
1232                  * When the merge fails, the result contains files
1233                  * with conflict markers. The cleanness flag is
1234                  * ignored, it was never actually used, as result of
1235                  * merge_trees has always overwritten it: the committed
1236                  * "conflicts" were already resolved.
1237                  */
1238                 discard_cache();
1239                 saved_b1 = o->branch1;
1240                 saved_b2 = o->branch2;
1241                 o->branch1 = "Temporary merge branch 1";
1242                 o->branch2 = "Temporary merge branch 2";
1243                 merge_recursive(o, merged_common_ancestors, iter->item,
1244                                 NULL, &merged_common_ancestors);
1245                 o->branch1 = saved_b1;
1246                 o->branch2 = saved_b2;
1247                 o->call_depth--;
1249                 if (!merged_common_ancestors)
1250                         die("merge returned no commit");
1251         }
1253         discard_cache();
1254         if (!o->call_depth)
1255                 read_cache();
1257         clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1258                             &mrtree);
1260         if (o->call_depth) {
1261                 *result = make_virtual_commit(mrtree, "merged tree");
1262                 commit_list_insert(h1, &(*result)->parents);
1263                 commit_list_insert(h2, &(*result)->parents->next);
1264         }
1265         flush_output(o);
1266         return clean;
1269 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1271         struct object *object;
1273         object = deref_tag(parse_object(sha1), name, strlen(name));
1274         if (!object)
1275                 return NULL;
1276         if (object->type == OBJ_TREE)
1277                 return make_virtual_commit((struct tree*)object, name);
1278         if (object->type != OBJ_COMMIT)
1279                 return NULL;
1280         if (parse_commit((struct commit *)object))
1281                 return NULL;
1282         return (struct commit *)object;
1285 int merge_recursive_generic(struct merge_options *o,
1286                             const unsigned char *head,
1287                             const unsigned char *merge,
1288                             int num_base_list,
1289                             const unsigned char **base_list,
1290                             struct commit **result)
1292         int clean, index_fd;
1293         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1294         struct commit *head_commit = get_ref(head, o->branch1);
1295         struct commit *next_commit = get_ref(merge, o->branch2);
1296         struct commit_list *ca = NULL;
1298         if (base_list) {
1299                 int i;
1300                 for (i = 0; i < num_base_list; ++i) {
1301                         struct commit *base;
1302                         if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1303                                 return error("Could not parse object '%s'",
1304                                         sha1_to_hex(base_list[i]));
1305                         commit_list_insert(base, &ca);
1306                 }
1307         }
1309         index_fd = hold_locked_index(lock, 1);
1310         clean = merge_recursive(o, head_commit, next_commit, ca,
1311                         result);
1312         if (active_cache_changed &&
1313                         (write_cache(index_fd, active_cache, active_nr) ||
1314                          commit_locked_index(lock)))
1315                 return error("Unable to write index.");
1317         return clean ? 0 : 1;
1320 static int merge_recursive_config(const char *var, const char *value, void *cb)
1322         struct merge_options *o = cb;
1323         if (!strcasecmp(var, "merge.verbosity")) {
1324                 o->verbosity = git_config_int(var, value);
1325                 return 0;
1326         }
1327         if (!strcasecmp(var, "diff.renamelimit")) {
1328                 o->diff_rename_limit = git_config_int(var, value);
1329                 return 0;
1330         }
1331         if (!strcasecmp(var, "merge.renamelimit")) {
1332                 o->merge_rename_limit = git_config_int(var, value);
1333                 return 0;
1334         }
1335         return git_xmerge_config(var, value, cb);
1338 void init_merge_options(struct merge_options *o)
1340         memset(o, 0, sizeof(struct merge_options));
1341         o->verbosity = 2;
1342         o->buffer_output = 1;
1343         o->diff_rename_limit = -1;
1344         o->merge_rename_limit = -1;
1345         git_config(merge_recursive_config, o);
1346         if (getenv("GIT_MERGE_VERBOSITY"))
1347                 o->verbosity =
1348                         strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1349         if (o->verbosity >= 5)
1350                 o->buffer_output = 0;
1351         strbuf_init(&o->obuf, 0);
1352         memset(&o->current_file_set, 0, sizeof(struct string_list));
1353         o->current_file_set.strdup_strings = 1;
1354         memset(&o->current_directory_set, 0, sizeof(struct string_list));
1355         o->current_directory_set.strdup_strings = 1;