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Counto-fix in merge-recursive
[git.git] / merge-recursive.c
blob65c018b3ea504036091a03a4e6bb12b1c0011f6e
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 "tree-walk.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "run-command.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "interpolate.h"
19 #include "attr.h"
20
21 static int subtree_merge;
22
23 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
24 {
25 unsigned char shifted[20];
26
27 /*
28 * NEEDSWORK: this limits the recursion depth to hardcoded
29 * value '2' to avoid excessive overhead.
30 */
31 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
32 if (!hashcmp(two->object.sha1, shifted))
33 return two;
34 return lookup_tree(shifted);
35 }
36
37 /*
38 * A virtual commit has
39 * - (const char *)commit->util set to the name, and
40 * - *(int *)commit->object.sha1 set to the virtual id.
41 */
42
43 static unsigned commit_list_count(const struct commit_list *l)
44 {
45 unsigned c = 0;
46 for (; l; l = l->next )
47 c++;
48 return c;
49 }
50
51 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
52 {
53 struct commit *commit = xcalloc(1, sizeof(struct commit));
54 static unsigned virtual_id = 1;
55 commit->tree = tree;
56 commit->util = (void*)comment;
57 *(int*)commit->object.sha1 = virtual_id++;
58 /* avoid warnings */
59 commit->object.parsed = 1;
60 return commit;
61 }
62
63 /*
64 * Since we use get_tree_entry(), which does not put the read object into
65 * the object pool, we cannot rely on a == b.
66 */
67 static int sha_eq(const unsigned char *a, const unsigned char *b)
68 {
69 if (!a && !b)
70 return 2;
71 return a && b && hashcmp(a, b) == 0;
72 }
73
74 /*
75 * Since we want to write the index eventually, we cannot reuse the index
76 * for these (temporary) data.
77 */
78 struct stage_data
79 {
80 struct
81 {
82 unsigned mode;
83 unsigned char sha[20];
84 } stages[4];
85 unsigned processed:1;
86 };
87
88 struct output_buffer
89 {
90 struct output_buffer *next;
91 char *str;
92 };
93
94 static struct path_list current_file_set = {NULL, 0, 0, 1};
95 static struct path_list current_directory_set = {NULL, 0, 0, 1};
96
97 static int call_depth = 0;
98 static int verbosity = 2;
99 static int buffer_output = 1;
100 static int do_progress = 1;
101 static unsigned last_percent;
102 static unsigned merged_cnt;
103 static unsigned total_cnt;
104 static volatile sig_atomic_t progress_update;
105 static struct output_buffer *output_list, *output_end;
106
107 static int show (int v)
108 {
109 return (!call_depth && verbosity >= v) || verbosity >= 5;
110 }
111
112 static void output(int v, const char *fmt, ...)
113 {
114 va_list args;
115 va_start(args, fmt);
116 if (buffer_output && show(v)) {
117 struct output_buffer *b = xmalloc(sizeof(*b));
118 nfvasprintf(&b->str, fmt, args);
119 b->next = NULL;
120 if (output_end)
121 output_end->next = b;
122 else
123 output_list = b;
124 output_end = b;
125 } else if (show(v)) {
126 int i;
127 for (i = call_depth; i--;)
128 fputs(" ", stdout);
129 vfprintf(stdout, fmt, args);
130 fputc('\n', stdout);
131 }
132 va_end(args);
133 }
134
135 static void flush_output()
136 {
137 struct output_buffer *b, *n;
138 for (b = output_list; b; b = n) {
139 int i;
140 for (i = call_depth; i--;)
141 fputs(" ", stdout);
142 fputs(b->str, stdout);
143 fputc('\n', stdout);
144 n = b->next;
145 free(b->str);
146 free(b);
147 }
148 output_list = NULL;
149 output_end = NULL;
150 }
151
152 static void output_commit_title(struct commit *commit)
153 {
154 int i;
155 flush_output();
156 for (i = call_depth; i--;)
157 fputs(" ", stdout);
158 if (commit->util)
159 printf("virtual %s\n", (char *)commit->util);
160 else {
161 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
162 if (parse_commit(commit) != 0)
163 printf("(bad commit)\n");
164 else {
165 const char *s;
166 int len;
167 for (s = commit->buffer; *s; s++)
168 if (*s == '\n' && s[1] == '\n') {
169 s += 2;
170 break;
171 }
172 for (len = 0; s[len] && '\n' != s[len]; len++)
173 ; /* do nothing */
174 printf("%.*s\n", len, s);
175 }
176 }
177 }
178
179 static void progress_interval(int signum)
180 {
181 progress_update = 1;
182 }
183
184 static void setup_progress_signal(void)
185 {
186 struct sigaction sa;
187 struct itimerval v;
188
189 memset(&sa, 0, sizeof(sa));
190 sa.sa_handler = progress_interval;
191 sigemptyset(&sa.sa_mask);
192 sa.sa_flags = SA_RESTART;
193 sigaction(SIGALRM, &sa, NULL);
194
195 v.it_interval.tv_sec = 1;
196 v.it_interval.tv_usec = 0;
197 v.it_value = v.it_interval;
198 setitimer(ITIMER_REAL, &v, NULL);
199 }
200
201 static void display_progress()
202 {
203 unsigned percent = total_cnt ? merged_cnt * 100 / total_cnt : 0;
204 if (progress_update || percent != last_percent) {
205 fprintf(stderr, "%4u%% (%u/%u) done\r",
206 percent, merged_cnt, total_cnt);
207 progress_update = 0;
208 last_percent = percent;
209 }
210 }
211
212 static struct cache_entry *make_cache_entry(unsigned int mode,
213 const unsigned char *sha1, const char *path, int stage, int refresh)
214 {
215 int size, len;
216 struct cache_entry *ce;
217
218 if (!verify_path(path))
219 return NULL;
220
221 len = strlen(path);
222 size = cache_entry_size(len);
223 ce = xcalloc(1, size);
224
225 hashcpy(ce->sha1, sha1);
226 memcpy(ce->name, path, len);
227 ce->ce_flags = create_ce_flags(len, stage);
228 ce->ce_mode = create_ce_mode(mode);
229
230 if (refresh)
231 return refresh_cache_entry(ce, 0);
232
233 return ce;
234 }
235
236 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
237 const char *path, int stage, int refresh, int options)
238 {
239 struct cache_entry *ce;
240 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
241 if (!ce)
242 return error("addinfo_cache failed for path '%s'", path);
243 return add_cache_entry(ce, options);
244 }
245
246 /*
247 * This is a global variable which is used in a number of places but
248 * only written to in the 'merge' function.
249 *
250 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
251 * don't update the working directory.
252 * 0 => Leave unmerged entries in the cache and update
253 * the working directory.
254 */
255 static int index_only = 0;
256
257 static int git_merge_trees(int index_only,
258 struct tree *common,
259 struct tree *head,
260 struct tree *merge)
261 {
262 int rc;
263 struct object_list *trees = NULL;
264 struct unpack_trees_options opts;
265
266 memset(&opts, 0, sizeof(opts));
267 if (index_only)
268 opts.index_only = 1;
269 else
270 opts.update = 1;
271 opts.merge = 1;
272 opts.head_idx = 2;
273 opts.fn = threeway_merge;
274
275 object_list_append(&common->object, &trees);
276 object_list_append(&head->object, &trees);
277 object_list_append(&merge->object, &trees);
278
279 rc = unpack_trees(trees, &opts);
280 cache_tree_free(&active_cache_tree);
281 return rc;
282 }
283
284 static int unmerged_index(void)
285 {
286 int i;
287 for (i = 0; i < active_nr; i++) {
288 struct cache_entry *ce = active_cache[i];
289 if (ce_stage(ce))
290 return 1;
291 }
292 return 0;
293 }
294
295 static struct tree *git_write_tree(void)
296 {
297 struct tree *result = NULL;
298
299 if (unmerged_index()) {
300 int i;
301 output(0, "There are unmerged index entries:");
302 for (i = 0; i < active_nr; i++) {
303 struct cache_entry *ce = active_cache[i];
304 if (ce_stage(ce))
305 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
306 }
307 return NULL;
308 }
309
310 if (!active_cache_tree)
311 active_cache_tree = cache_tree();
312
313 if (!cache_tree_fully_valid(active_cache_tree) &&
314 cache_tree_update(active_cache_tree,
315 active_cache, active_nr, 0, 0) < 0)
316 die("error building trees");
317
318 result = lookup_tree(active_cache_tree->sha1);
319
320 return result;
321 }
322
323 static int save_files_dirs(const unsigned char *sha1,
324 const char *base, int baselen, const char *path,
325 unsigned int mode, int stage)
326 {
327 int len = strlen(path);
328 char *newpath = xmalloc(baselen + len + 1);
329 memcpy(newpath, base, baselen);
330 memcpy(newpath + baselen, path, len);
331 newpath[baselen + len] = '\0';
332
333 if (S_ISDIR(mode))
334 path_list_insert(newpath, &current_directory_set);
335 else
336 path_list_insert(newpath, &current_file_set);
337 free(newpath);
338
339 return READ_TREE_RECURSIVE;
340 }
341
342 static int get_files_dirs(struct tree *tree)
343 {
344 int n;
345 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
346 return 0;
347 n = current_file_set.nr + current_directory_set.nr;
348 return n;
349 }
350
351 /*
352 * Returns a index_entry instance which doesn't have to correspond to
353 * a real cache entry in Git's index.
354 */
355 static struct stage_data *insert_stage_data(const char *path,
356 struct tree *o, struct tree *a, struct tree *b,
357 struct path_list *entries)
358 {
359 struct path_list_item *item;
360 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
361 get_tree_entry(o->object.sha1, path,
362 e->stages[1].sha, &e->stages[1].mode);
363 get_tree_entry(a->object.sha1, path,
364 e->stages[2].sha, &e->stages[2].mode);
365 get_tree_entry(b->object.sha1, path,
366 e->stages[3].sha, &e->stages[3].mode);
367 item = path_list_insert(path, entries);
368 item->util = e;
369 return e;
370 }
371
372 /*
373 * Create a dictionary mapping file names to stage_data objects. The
374 * dictionary contains one entry for every path with a non-zero stage entry.
375 */
376 static struct path_list *get_unmerged(void)
377 {
378 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
379 int i;
380
381 unmerged->strdup_paths = 1;
382 total_cnt += active_nr;
383
384 for (i = 0; i < active_nr; i++, merged_cnt++) {
385 struct path_list_item *item;
386 struct stage_data *e;
387 struct cache_entry *ce = active_cache[i];
388 if (do_progress)
389 display_progress();
390 if (!ce_stage(ce))
391 continue;
392
393 item = path_list_lookup(ce->name, unmerged);
394 if (!item) {
395 item = path_list_insert(ce->name, unmerged);
396 item->util = xcalloc(1, sizeof(struct stage_data));
397 }
398 e = item->util;
399 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
400 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
401 }
402
403 return unmerged;
404 }
405
406 struct rename
407 {
408 struct diff_filepair *pair;
409 struct stage_data *src_entry;
410 struct stage_data *dst_entry;
411 unsigned processed:1;
412 };
413
414 /*
415 * Get information of all renames which occurred between 'o_tree' and
416 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
417 * 'b_tree') to be able to associate the correct cache entries with
418 * the rename information. 'tree' is always equal to either a_tree or b_tree.
419 */
420 static struct path_list *get_renames(struct tree *tree,
421 struct tree *o_tree,
422 struct tree *a_tree,
423 struct tree *b_tree,
424 struct path_list *entries)
425 {
426 int i;
427 struct path_list *renames;
428 struct diff_options opts;
429
430 renames = xcalloc(1, sizeof(struct path_list));
431 diff_setup(&opts);
432 opts.recursive = 1;
433 opts.detect_rename = DIFF_DETECT_RENAME;
434 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
435 if (diff_setup_done(&opts) < 0)
436 die("diff setup failed");
437 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
438 diffcore_std(&opts);
439 for (i = 0; i < diff_queued_diff.nr; ++i) {
440 struct path_list_item *item;
441 struct rename *re;
442 struct diff_filepair *pair = diff_queued_diff.queue[i];
443 if (pair->status != 'R') {
444 diff_free_filepair(pair);
445 continue;
446 }
447 re = xmalloc(sizeof(*re));
448 re->processed = 0;
449 re->pair = pair;
450 item = path_list_lookup(re->pair->one->path, entries);
451 if (!item)
452 re->src_entry = insert_stage_data(re->pair->one->path,
453 o_tree, a_tree, b_tree, entries);
454 else
455 re->src_entry = item->util;
456
457 item = path_list_lookup(re->pair->two->path, entries);
458 if (!item)
459 re->dst_entry = insert_stage_data(re->pair->two->path,
460 o_tree, a_tree, b_tree, entries);
461 else
462 re->dst_entry = item->util;
463 item = path_list_insert(pair->one->path, renames);
464 item->util = re;
465 }
466 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
467 diff_queued_diff.nr = 0;
468 diff_flush(&opts);
469 return renames;
470 }
471
472 static int update_stages(const char *path, struct diff_filespec *o,
473 struct diff_filespec *a, struct diff_filespec *b,
474 int clear)
475 {
476 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
477 if (clear)
478 if (remove_file_from_cache(path))
479 return -1;
480 if (o)
481 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
482 return -1;
483 if (a)
484 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
485 return -1;
486 if (b)
487 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
488 return -1;
489 return 0;
490 }
491
492 static int remove_path(const char *name)
493 {
494 int ret, len;
495 char *slash, *dirs;
496
497 ret = unlink(name);
498 if (ret)
499 return ret;
500 len = strlen(name);
501 dirs = xmalloc(len+1);
502 memcpy(dirs, name, len);
503 dirs[len] = '\0';
504 while ((slash = strrchr(name, '/'))) {
505 *slash = '\0';
506 len = slash - name;
507 if (rmdir(name) != 0)
508 break;
509 }
510 free(dirs);
511 return ret;
512 }
513
514 static int remove_file(int clean, const char *path, int no_wd)
515 {
516 int update_cache = index_only || clean;
517 int update_working_directory = !index_only && !no_wd;
518
519 if (update_cache) {
520 if (remove_file_from_cache(path))
521 return -1;
522 }
523 if (update_working_directory) {
524 unlink(path);
525 if (errno != ENOENT || errno != EISDIR)
526 return -1;
527 remove_path(path);
528 }
529 return 0;
530 }
531
532 static char *unique_path(const char *path, const char *branch)
533 {
534 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
535 int suffix = 0;
536 struct stat st;
537 char *p = newpath + strlen(path);
538 strcpy(newpath, path);
539 *(p++) = '~';
540 strcpy(p, branch);
541 for (; *p; ++p)
542 if ('/' == *p)
543 *p = '_';
544 while (path_list_has_path(&current_file_set, newpath) ||
545 path_list_has_path(&current_directory_set, newpath) ||
546 lstat(newpath, &st) == 0)
547 sprintf(p, "_%d", suffix++);
548
549 path_list_insert(newpath, &current_file_set);
550 return newpath;
551 }
552
553 static int mkdir_p(const char *path, unsigned long mode)
554 {
555 /* path points to cache entries, so xstrdup before messing with it */
556 char *buf = xstrdup(path);
557 int result = safe_create_leading_directories(buf);
558 free(buf);
559 return result;
560 }
561
562 static void flush_buffer(int fd, const char *buf, unsigned long size)
563 {
564 while (size > 0) {
565 long ret = write_in_full(fd, buf, size);
566 if (ret < 0) {
567 /* Ignore epipe */
568 if (errno == EPIPE)
569 break;
570 die("merge-recursive: %s", strerror(errno));
571 } else if (!ret) {
572 die("merge-recursive: disk full?");
573 }
574 size -= ret;
575 buf += ret;
576 }
577 }
578
579 static void update_file_flags(const unsigned char *sha,
580 unsigned mode,
581 const char *path,
582 int update_cache,
583 int update_wd)
584 {
585 if (index_only)
586 update_wd = 0;
587
588 if (update_wd) {
589 enum object_type type;
590 void *buf;
591 unsigned long size;
592
593 buf = read_sha1_file(sha, &type, &size);
594 if (!buf)
595 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
596 if (type != OBJ_BLOB)
597 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
598
599 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
600 int fd;
601 if (mkdir_p(path, 0777))
602 die("failed to create path %s: %s", path, strerror(errno));
603 unlink(path);
604 if (mode & 0100)
605 mode = 0777;
606 else
607 mode = 0666;
608 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
609 if (fd < 0)
610 die("failed to open %s: %s", path, strerror(errno));
611 flush_buffer(fd, buf, size);
612 close(fd);
613 } else if (S_ISLNK(mode)) {
614 char *lnk = xmalloc(size + 1);
615 memcpy(lnk, buf, size);
616 lnk[size] = '\0';
617 mkdir_p(path, 0777);
618 unlink(path);
619 symlink(lnk, path);
620 free(lnk);
621 } else
622 die("do not know what to do with %06o %s '%s'",
623 mode, sha1_to_hex(sha), path);
624 }
625 if (update_cache)
626 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
627 }
628
629 static void update_file(int clean,
630 const unsigned char *sha,
631 unsigned mode,
632 const char *path)
633 {
634 update_file_flags(sha, mode, path, index_only || clean, !index_only);
635 }
636
637 /* Low level file merging, update and removal */
638
639 struct merge_file_info
640 {
641 unsigned char sha[20];
642 unsigned mode;
643 unsigned clean:1,
644 merge:1;
645 };
646
647 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
648 {
649 unsigned long size;
650 enum object_type type;
651
652 if (!hashcmp(sha1, null_sha1)) {
653 mm->ptr = xstrdup("");
654 mm->size = 0;
655 return;
656 }
657
658 mm->ptr = read_sha1_file(sha1, &type, &size);
659 if (!mm->ptr || type != OBJ_BLOB)
660 die("unable to read blob object %s", sha1_to_hex(sha1));
661 mm->size = size;
662 }
663
664 /*
665 * Customizable low-level merge drivers support.
666 */
667
668 struct ll_merge_driver;
669 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
670 const char *path,
671 mmfile_t *orig,
672 mmfile_t *src1, const char *name1,
673 mmfile_t *src2, const char *name2,
674 mmbuffer_t *result);
675
676 struct ll_merge_driver {
677 const char *name;
678 const char *description;
679 ll_merge_fn fn;
680 const char *recursive;
681 struct ll_merge_driver *next;
682 char *cmdline;
683 };
684
685 /*
686 * Built-in low-levels
687 */
688 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
689 const char *path_unused,
690 mmfile_t *orig,
691 mmfile_t *src1, const char *name1,
692 mmfile_t *src2, const char *name2,
693 mmbuffer_t *result)
694 {
695 xpparam_t xpp;
696
697 memset(&xpp, 0, sizeof(xpp));
698 return xdl_merge(orig,
699 src1, name1,
700 src2, name2,
701 &xpp, XDL_MERGE_ZEALOUS,
702 result);
703 }
704
705 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
706 const char *path_unused,
707 mmfile_t *orig,
708 mmfile_t *src1, const char *name1,
709 mmfile_t *src2, const char *name2,
710 mmbuffer_t *result)
711 {
712 char *src, *dst;
713 long size;
714 const int marker_size = 7;
715
716 int status = ll_xdl_merge(drv_unused, path_unused,
717 orig, src1, NULL, src2, NULL, result);
718 if (status <= 0)
719 return status;
720 size = result->size;
721 src = dst = result->ptr;
722 while (size) {
723 char ch;
724 if ((marker_size < size) &&
725 (*src == '<' || *src == '=' || *src == '>')) {
726 int i;
727 ch = *src;
728 for (i = 0; i < marker_size; i++)
729 if (src[i] != ch)
730 goto not_a_marker;
731 if (src[marker_size] != '\n')
732 goto not_a_marker;
733 src += marker_size + 1;
734 size -= marker_size + 1;
735 continue;
736 }
737 not_a_marker:
738 do {
739 ch = *src++;
740 *dst++ = ch;
741 size--;
742 } while (ch != '\n' && size);
743 }
744 result->size = dst - result->ptr;
745 return 0;
746 }
747
748 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
749 const char *path_unused,
750 mmfile_t *orig,
751 mmfile_t *src1, const char *name1,
752 mmfile_t *src2, const char *name2,
753 mmbuffer_t *result)
754 {
755 /*
756 * The tentative merge result is "ours" for the final round,
757 * or common ancestor for an internal merge. Still return
758 * "conflicted merge" status.
759 */
760 mmfile_t *stolen = index_only ? orig : src1;
761
762 result->ptr = stolen->ptr;
763 result->size = stolen->size;
764 stolen->ptr = NULL;
765 return 1;
766 }
767
768 #define LL_BINARY_MERGE 0
769 #define LL_TEXT_MERGE 1
770 #define LL_UNION_MERGE 2
771 static struct ll_merge_driver ll_merge_drv[] = {
772 { "binary", "built-in binary merge", ll_binary_merge },
773 { "text", "built-in 3-way text merge", ll_xdl_merge },
774 { "union", "built-in union merge", ll_union_merge },
775 };
776
777 static void create_temp(mmfile_t *src, char *path)
778 {
779 int fd;
780
781 strcpy(path, ".merge_file_XXXXXX");
782 fd = mkstemp(path);
783 if (fd < 0)
784 die("unable to create temp-file");
785 if (write_in_full(fd, src->ptr, src->size) != src->size)
786 die("unable to write temp-file");
787 close(fd);
788 }
789
790 /*
791 * User defined low-level merge driver support.
792 */
793 static int ll_ext_merge(const struct ll_merge_driver *fn,
794 const char *path,
795 mmfile_t *orig,
796 mmfile_t *src1, const char *name1,
797 mmfile_t *src2, const char *name2,
798 mmbuffer_t *result)
799 {
800 char temp[3][50];
801 char cmdbuf[2048];
802 struct interp table[] = {
803 { "%O" },
804 { "%A" },
805 { "%B" },
806 };
807 struct child_process child;
808 const char *args[20];
809 int status, fd, i;
810 struct stat st;
811
812 if (fn->cmdline == NULL)
813 die("custom merge driver %s lacks command line.", fn->name);
814
815 result->ptr = NULL;
816 result->size = 0;
817 create_temp(orig, temp[0]);
818 create_temp(src1, temp[1]);
819 create_temp(src2, temp[2]);
820
821 interp_set_entry(table, 0, temp[0]);
822 interp_set_entry(table, 1, temp[1]);
823 interp_set_entry(table, 2, temp[2]);
824
825 output(1, "merging %s using %s", path,
826 fn->description ? fn->description : fn->name);
827
828 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
829
830 memset(&child, 0, sizeof(child));
831 child.argv = args;
832 args[0] = "sh";
833 args[1] = "-c";
834 args[2] = cmdbuf;
835 args[3] = NULL;
836
837 status = run_command(&child);
838 if (status < -ERR_RUN_COMMAND_FORK)
839 ; /* failure in run-command */
840 else
841 status = -status;
842 fd = open(temp[1], O_RDONLY);
843 if (fd < 0)
844 goto bad;
845 if (fstat(fd, &st))
846 goto close_bad;
847 result->size = st.st_size;
848 result->ptr = xmalloc(result->size + 1);
849 if (read_in_full(fd, result->ptr, result->size) != result->size) {
850 free(result->ptr);
851 result->ptr = NULL;
852 result->size = 0;
853 }
854 close_bad:
855 close(fd);
856 bad:
857 for (i = 0; i < 3; i++)
858 unlink(temp[i]);
859 return status;
860 }
861
862 /*
863 * merge.default and merge.driver configuration items
864 */
865 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
866 static const char *default_ll_merge;
867
868 static int read_merge_config(const char *var, const char *value)
869 {
870 struct ll_merge_driver *fn;
871 const char *ep, *name;
872 int namelen;
873
874 if (!strcmp(var, "merge.default")) {
875 if (value)
876 default_ll_merge = strdup(value);
877 return 0;
878 }
879
880 /*
881 * We are not interested in anything but "merge.<name>.variable";
882 * especially, we do not want to look at variables such as
883 * "merge.summary", "merge.tool", and "merge.verbosity".
884 */
885 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
886 return 0;
887
888 /*
889 * Find existing one as we might be processing merge.<name>.var2
890 * after seeing merge.<name>.var1.
891 */
892 name = var + 6;
893 namelen = ep - name;
894 for (fn = ll_user_merge; fn; fn = fn->next)
895 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
896 break;
897 if (!fn) {
898 char *namebuf;
899 fn = xcalloc(1, sizeof(struct ll_merge_driver));
900 namebuf = xmalloc(namelen + 1);
901 memcpy(namebuf, name, namelen);
902 namebuf[namelen] = 0;
903 fn->name = namebuf;
904 fn->fn = ll_ext_merge;
905 fn->next = *ll_user_merge_tail;
906 *ll_user_merge_tail = fn;
907 }
908
909 ep++;
910
911 if (!strcmp("name", ep)) {
912 if (!value)
913 return error("%s: lacks value", var);
914 fn->description = strdup(value);
915 return 0;
916 }
917
918 if (!strcmp("driver", ep)) {
919 if (!value)
920 return error("%s: lacks value", var);
921 /*
922 * merge.<name>.driver specifies the command line:
923 *
924 * command-line
925 *
926 * The command-line will be interpolated with the following
927 * tokens and is given to the shell:
928 *
929 * %O - temporary file name for the merge base.
930 * %A - temporary file name for our version.
931 * %B - temporary file name for the other branches' version.
932 *
933 * The external merge driver should write the results in the
934 * file named by %A, and signal that it has done with zero exit
935 * status.
936 */
937 fn->cmdline = strdup(value);
938 return 0;
939 }
940
941 if (!strcmp("recursive", ep)) {
942 if (!value)
943 return error("%s: lacks value", var);
944 fn->recursive = strdup(value);
945 return 0;
946 }
947
948 return 0;
949 }
950
951 static void initialize_ll_merge(void)
952 {
953 if (ll_user_merge_tail)
954 return;
955 ll_user_merge_tail = &ll_user_merge;
956 git_config(read_merge_config);
957 }
958
959 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
960 {
961 struct ll_merge_driver *fn;
962 const char *name;
963 int i;
964
965 initialize_ll_merge();
966
967 if (ATTR_TRUE(merge_attr))
968 return &ll_merge_drv[LL_TEXT_MERGE];
969 else if (ATTR_FALSE(merge_attr))
970 return &ll_merge_drv[LL_BINARY_MERGE];
971 else if (ATTR_UNSET(merge_attr)) {
972 if (!default_ll_merge)
973 return &ll_merge_drv[LL_TEXT_MERGE];
974 else
975 name = default_ll_merge;
976 }
977 else
978 name = merge_attr;
979
980 for (fn = ll_user_merge; fn; fn = fn->next)
981 if (!strcmp(fn->name, name))
982 return fn;
983
984 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
985 if (!strcmp(ll_merge_drv[i].name, name))
986 return &ll_merge_drv[i];
987
988 /* default to the 3-way */
989 return &ll_merge_drv[LL_TEXT_MERGE];
990 }
991
992 static const char *git_path_check_merge(const char *path)
993 {
994 static struct git_attr_check attr_merge_check;
995
996 if (!attr_merge_check.attr)
997 attr_merge_check.attr = git_attr("merge", 5);
998
999 if (git_checkattr(path, 1, &attr_merge_check))
1000 return NULL;
1001 return attr_merge_check.value;
1002 }
1003
1004 static int ll_merge(mmbuffer_t *result_buf,
1005 struct diff_filespec *o,
1006 struct diff_filespec *a,
1007 struct diff_filespec *b,
1008 const char *branch1,
1009 const char *branch2)
1010 {
1011 mmfile_t orig, src1, src2;
1012 char *name1, *name2;
1013 int merge_status;
1014 const char *ll_driver_name;
1015 const struct ll_merge_driver *driver;
1016
1017 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1018 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1019
1020 fill_mm(o->sha1, &orig);
1021 fill_mm(a->sha1, &src1);
1022 fill_mm(b->sha1, &src2);
1023
1024 ll_driver_name = git_path_check_merge(a->path);
1025 driver = find_ll_merge_driver(ll_driver_name);
1026
1027 if (index_only && driver->recursive) {
1028 void *merge_attr;
1029
1030 ll_driver_name = driver->recursive;
1031 merge_attr = git_attr(ll_driver_name, strlen(ll_driver_name));
1032 driver = find_ll_merge_driver(merge_attr);
1033 }
1034 merge_status = driver->fn(driver, a->path,
1035 &orig, &src1, name1, &src2, name2,
1036 result_buf);
1037
1038 free(name1);
1039 free(name2);
1040 free(orig.ptr);
1041 free(src1.ptr);
1042 free(src2.ptr);
1043 return merge_status;
1044 }
1045
1046 static struct merge_file_info merge_file(struct diff_filespec *o,
1047 struct diff_filespec *a, struct diff_filespec *b,
1048 const char *branch1, const char *branch2)
1049 {
1050 struct merge_file_info result;
1051 result.merge = 0;
1052 result.clean = 1;
1053
1054 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1055 result.clean = 0;
1056 if (S_ISREG(a->mode)) {
1057 result.mode = a->mode;
1058 hashcpy(result.sha, a->sha1);
1059 } else {
1060 result.mode = b->mode;
1061 hashcpy(result.sha, b->sha1);
1062 }
1063 } else {
1064 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1065 result.merge = 1;
1066
1067 result.mode = a->mode == o->mode ? b->mode: a->mode;
1068
1069 if (sha_eq(a->sha1, o->sha1))
1070 hashcpy(result.sha, b->sha1);
1071 else if (sha_eq(b->sha1, o->sha1))
1072 hashcpy(result.sha, a->sha1);
1073 else if (S_ISREG(a->mode)) {
1074 mmbuffer_t result_buf;
1075 int merge_status;
1076
1077 merge_status = ll_merge(&result_buf, o, a, b,
1078 branch1, branch2);
1079
1080 if ((merge_status < 0) || !result_buf.ptr)
1081 die("Failed to execute internal merge");
1082
1083 if (write_sha1_file(result_buf.ptr, result_buf.size,
1084 blob_type, result.sha))
1085 die("Unable to add %s to database",
1086 a->path);
1087
1088 free(result_buf.ptr);
1089 result.clean = (merge_status == 0);
1090 } else {
1091 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1092 die("cannot merge modes?");
1093
1094 hashcpy(result.sha, a->sha1);
1095
1096 if (!sha_eq(a->sha1, b->sha1))
1097 result.clean = 0;
1098 }
1099 }
1100
1101 return result;
1102 }
1103
1104 static void conflict_rename_rename(struct rename *ren1,
1105 const char *branch1,
1106 struct rename *ren2,
1107 const char *branch2)
1108 {
1109 char *del[2];
1110 int delp = 0;
1111 const char *ren1_dst = ren1->pair->two->path;
1112 const char *ren2_dst = ren2->pair->two->path;
1113 const char *dst_name1 = ren1_dst;
1114 const char *dst_name2 = ren2_dst;
1115 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1116 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1117 output(1, "%s is a directory in %s added as %s instead",
1118 ren1_dst, branch2, dst_name1);
1119 remove_file(0, ren1_dst, 0);
1120 }
1121 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1122 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1123 output(1, "%s is a directory in %s added as %s instead",
1124 ren2_dst, branch1, dst_name2);
1125 remove_file(0, ren2_dst, 0);
1126 }
1127 if (index_only) {
1128 remove_file_from_cache(dst_name1);
1129 remove_file_from_cache(dst_name2);
1130 /*
1131 * Uncomment to leave the conflicting names in the resulting tree
1132 *
1133 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1134 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1135 */
1136 } else {
1137 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1138 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1139 }
1140 while (delp--)
1141 free(del[delp]);
1142 }
1143
1144 static void conflict_rename_dir(struct rename *ren1,
1145 const char *branch1)
1146 {
1147 char *new_path = unique_path(ren1->pair->two->path, branch1);
1148 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1149 remove_file(0, ren1->pair->two->path, 0);
1150 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1151 free(new_path);
1152 }
1153
1154 static void conflict_rename_rename_2(struct rename *ren1,
1155 const char *branch1,
1156 struct rename *ren2,
1157 const char *branch2)
1158 {
1159 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1160 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1161 output(1, "Renamed %s to %s and %s to %s instead",
1162 ren1->pair->one->path, new_path1,
1163 ren2->pair->one->path, new_path2);
1164 remove_file(0, ren1->pair->two->path, 0);
1165 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1166 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1167 free(new_path2);
1168 free(new_path1);
1169 }
1170
1171 static int process_renames(struct path_list *a_renames,
1172 struct path_list *b_renames,
1173 const char *a_branch,
1174 const char *b_branch)
1175 {
1176 int clean_merge = 1, i, j;
1177 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1178 const struct rename *sre;
1179
1180 for (i = 0; i < a_renames->nr; i++) {
1181 sre = a_renames->items[i].util;
1182 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1183 = sre->dst_entry;
1184 }
1185 for (i = 0; i < b_renames->nr; i++) {
1186 sre = b_renames->items[i].util;
1187 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1188 = sre->dst_entry;
1189 }
1190
1191 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1192 int compare;
1193 char *src;
1194 struct path_list *renames1, *renames2, *renames2Dst;
1195 struct rename *ren1 = NULL, *ren2 = NULL;
1196 const char *branch1, *branch2;
1197 const char *ren1_src, *ren1_dst;
1198
1199 if (i >= a_renames->nr) {
1200 compare = 1;
1201 ren2 = b_renames->items[j++].util;
1202 } else if (j >= b_renames->nr) {
1203 compare = -1;
1204 ren1 = a_renames->items[i++].util;
1205 } else {
1206 compare = strcmp(a_renames->items[i].path,
1207 b_renames->items[j].path);
1208 if (compare <= 0)
1209 ren1 = a_renames->items[i++].util;
1210 if (compare >= 0)
1211 ren2 = b_renames->items[j++].util;
1212 }
1213
1214 /* TODO: refactor, so that 1/2 are not needed */
1215 if (ren1) {
1216 renames1 = a_renames;
1217 renames2 = b_renames;
1218 renames2Dst = &b_by_dst;
1219 branch1 = a_branch;
1220 branch2 = b_branch;
1221 } else {
1222 struct rename *tmp;
1223 renames1 = b_renames;
1224 renames2 = a_renames;
1225 renames2Dst = &a_by_dst;
1226 branch1 = b_branch;
1227 branch2 = a_branch;
1228 tmp = ren2;
1229 ren2 = ren1;
1230 ren1 = tmp;
1231 }
1232 src = ren1->pair->one->path;
1233
1234 ren1->dst_entry->processed = 1;
1235 ren1->src_entry->processed = 1;
1236
1237 if (ren1->processed)
1238 continue;
1239 ren1->processed = 1;
1240
1241 ren1_src = ren1->pair->one->path;
1242 ren1_dst = ren1->pair->two->path;
1243
1244 if (ren2) {
1245 const char *ren2_src = ren2->pair->one->path;
1246 const char *ren2_dst = ren2->pair->two->path;
1247 /* Renamed in 1 and renamed in 2 */
1248 if (strcmp(ren1_src, ren2_src) != 0)
1249 die("ren1.src != ren2.src");
1250 ren2->dst_entry->processed = 1;
1251 ren2->processed = 1;
1252 if (strcmp(ren1_dst, ren2_dst) != 0) {
1253 clean_merge = 0;
1254 output(1, "CONFLICT (rename/rename): "
1255 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1256 "rename \"%s\"->\"%s\" in \"%s\"%s",
1257 src, ren1_dst, branch1,
1258 src, ren2_dst, branch2,
1259 index_only ? " (left unresolved)": "");
1260 if (index_only) {
1261 remove_file_from_cache(src);
1262 update_file(0, ren1->pair->one->sha1,
1263 ren1->pair->one->mode, src);
1264 }
1265 conflict_rename_rename(ren1, branch1, ren2, branch2);
1266 } else {
1267 struct merge_file_info mfi;
1268 remove_file(1, ren1_src, 1);
1269 mfi = merge_file(ren1->pair->one,
1270 ren1->pair->two,
1271 ren2->pair->two,
1272 branch1,
1273 branch2);
1274 if (mfi.merge || !mfi.clean)
1275 output(1, "Renamed %s->%s", src, ren1_dst);
1276
1277 if (mfi.merge)
1278 output(2, "Auto-merged %s", ren1_dst);
1279
1280 if (!mfi.clean) {
1281 output(1, "CONFLICT (content): merge conflict in %s",
1282 ren1_dst);
1283 clean_merge = 0;
1284
1285 if (!index_only)
1286 update_stages(ren1_dst,
1287 ren1->pair->one,
1288 ren1->pair->two,
1289 ren2->pair->two,
1290 1 /* clear */);
1291 }
1292 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1293 }
1294 } else {
1295 /* Renamed in 1, maybe changed in 2 */
1296 struct path_list_item *item;
1297 /* we only use sha1 and mode of these */
1298 struct diff_filespec src_other, dst_other;
1299 int try_merge, stage = a_renames == renames1 ? 3: 2;
1300
1301 remove_file(1, ren1_src, index_only || stage == 3);
1302
1303 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1304 src_other.mode = ren1->src_entry->stages[stage].mode;
1305 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1306 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1307
1308 try_merge = 0;
1309
1310 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1311 clean_merge = 0;
1312 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1313 " directory %s added in %s",
1314 ren1_src, ren1_dst, branch1,
1315 ren1_dst, branch2);
1316 conflict_rename_dir(ren1, branch1);
1317 } else if (sha_eq(src_other.sha1, null_sha1)) {
1318 clean_merge = 0;
1319 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1320 "and deleted in %s",
1321 ren1_src, ren1_dst, branch1,
1322 branch2);
1323 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1324 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1325 const char *new_path;
1326 clean_merge = 0;
1327 try_merge = 1;
1328 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1329 "%s added in %s",
1330 ren1_src, ren1_dst, branch1,
1331 ren1_dst, branch2);
1332 new_path = unique_path(ren1_dst, branch2);
1333 output(1, "Added as %s instead", new_path);
1334 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1335 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1336 ren2 = item->util;
1337 clean_merge = 0;
1338 ren2->processed = 1;
1339 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1340 "Renamed %s->%s in %s",
1341 ren1_src, ren1_dst, branch1,
1342 ren2->pair->one->path, ren2->pair->two->path, branch2);
1343 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1344 } else
1345 try_merge = 1;
1346
1347 if (try_merge) {
1348 struct diff_filespec *o, *a, *b;
1349 struct merge_file_info mfi;
1350 src_other.path = (char *)ren1_src;
1351
1352 o = ren1->pair->one;
1353 if (a_renames == renames1) {
1354 a = ren1->pair->two;
1355 b = &src_other;
1356 } else {
1357 b = ren1->pair->two;
1358 a = &src_other;
1359 }
1360 mfi = merge_file(o, a, b,
1361 a_branch, b_branch);
1362
1363 if (mfi.merge || !mfi.clean)
1364 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1365 if (mfi.merge)
1366 output(2, "Auto-merged %s", ren1_dst);
1367 if (!mfi.clean) {
1368 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1369 ren1_dst);
1370 clean_merge = 0;
1371
1372 if (!index_only)
1373 update_stages(ren1_dst,
1374 o, a, b, 1);
1375 }
1376 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1377 }
1378 }
1379 }
1380 path_list_clear(&a_by_dst, 0);
1381 path_list_clear(&b_by_dst, 0);
1382
1383 return clean_merge;
1384 }
1385
1386 static unsigned char *has_sha(const unsigned char *sha)
1387 {
1388 return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
1389 }
1390
1391 /* Per entry merge function */
1392 static int process_entry(const char *path, struct stage_data *entry,
1393 const char *branch1,
1394 const char *branch2)
1395 {
1396 /*
1397 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1398 print_index_entry("\tpath: ", entry);
1399 */
1400 int clean_merge = 1;
1401 unsigned char *o_sha = has_sha(entry->stages[1].sha);
1402 unsigned char *a_sha = has_sha(entry->stages[2].sha);
1403 unsigned char *b_sha = has_sha(entry->stages[3].sha);
1404 unsigned o_mode = entry->stages[1].mode;
1405 unsigned a_mode = entry->stages[2].mode;
1406 unsigned b_mode = entry->stages[3].mode;
1407
1408 if (o_sha && (!a_sha || !b_sha)) {
1409 /* Case A: Deleted in one */
1410 if ((!a_sha && !b_sha) ||
1411 (sha_eq(a_sha, o_sha) && !b_sha) ||
1412 (!a_sha && sha_eq(b_sha, o_sha))) {
1413 /* Deleted in both or deleted in one and
1414 * unchanged in the other */
1415 if (a_sha)
1416 output(2, "Removed %s", path);
1417 /* do not touch working file if it did not exist */
1418 remove_file(1, path, !a_sha);
1419 } else {
1420 /* Deleted in one and changed in the other */
1421 clean_merge = 0;
1422 if (!a_sha) {
1423 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1424 "and modified in %s. Version %s of %s left in tree.",
1425 path, branch1,
1426 branch2, branch2, path);
1427 update_file(0, b_sha, b_mode, path);
1428 } else {
1429 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1430 "and modified in %s. Version %s of %s left in tree.",
1431 path, branch2,
1432 branch1, branch1, path);
1433 update_file(0, a_sha, a_mode, path);
1434 }
1435 }
1436
1437 } else if ((!o_sha && a_sha && !b_sha) ||
1438 (!o_sha && !a_sha && b_sha)) {
1439 /* Case B: Added in one. */
1440 const char *add_branch;
1441 const char *other_branch;
1442 unsigned mode;
1443 const unsigned char *sha;
1444 const char *conf;
1445
1446 if (a_sha) {
1447 add_branch = branch1;
1448 other_branch = branch2;
1449 mode = a_mode;
1450 sha = a_sha;
1451 conf = "file/directory";
1452 } else {
1453 add_branch = branch2;
1454 other_branch = branch1;
1455 mode = b_mode;
1456 sha = b_sha;
1457 conf = "directory/file";
1458 }
1459 if (path_list_has_path(&current_directory_set, path)) {
1460 const char *new_path = unique_path(path, add_branch);
1461 clean_merge = 0;
1462 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1463 "Added %s as %s",
1464 conf, path, other_branch, path, new_path);
1465 remove_file(0, path, 0);
1466 update_file(0, sha, mode, new_path);
1467 } else {
1468 output(2, "Added %s", path);
1469 update_file(1, sha, mode, path);
1470 }
1471 } else if (a_sha && b_sha) {
1472 /* Case C: Added in both (check for same permissions) and */
1473 /* case D: Modified in both, but differently. */
1474 const char *reason = "content";
1475 struct merge_file_info mfi;
1476 struct diff_filespec o, a, b;
1477
1478 if (!o_sha) {
1479 reason = "add/add";
1480 o_sha = (unsigned char *)null_sha1;
1481 }
1482 output(2, "Auto-merged %s", path);
1483 o.path = a.path = b.path = (char *)path;
1484 hashcpy(o.sha1, o_sha);
1485 o.mode = o_mode;
1486 hashcpy(a.sha1, a_sha);
1487 a.mode = a_mode;
1488 hashcpy(b.sha1, b_sha);
1489 b.mode = b_mode;
1490
1491 mfi = merge_file(&o, &a, &b,
1492 branch1, branch2);
1493
1494 if (mfi.clean)
1495 update_file(1, mfi.sha, mfi.mode, path);
1496 else {
1497 clean_merge = 0;
1498 output(1, "CONFLICT (%s): Merge conflict in %s",
1499 reason, path);
1500
1501 if (index_only)
1502 update_file(0, mfi.sha, mfi.mode, path);
1503 else
1504 update_file_flags(mfi.sha, mfi.mode, path,
1505 0 /* update_cache */, 1 /* update_working_directory */);
1506 }
1507 } else
1508 die("Fatal merge failure, shouldn't happen.");
1509
1510 return clean_merge;
1511 }
1512
1513 static int merge_trees(struct tree *head,
1514 struct tree *merge,
1515 struct tree *common,
1516 const char *branch1,
1517 const char *branch2,
1518 struct tree **result)
1519 {
1520 int code, clean;
1521
1522 if (subtree_merge) {
1523 merge = shift_tree_object(head, merge);
1524 common = shift_tree_object(head, common);
1525 }
1526
1527 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1528 output(0, "Already uptodate!");
1529 *result = head;
1530 return 1;
1531 }
1532
1533 code = git_merge_trees(index_only, common, head, merge);
1534
1535 if (code != 0)
1536 die("merging of trees %s and %s failed",
1537 sha1_to_hex(head->object.sha1),
1538 sha1_to_hex(merge->object.sha1));
1539
1540 if (unmerged_index()) {
1541 struct path_list *entries, *re_head, *re_merge;
1542 int i;
1543 path_list_clear(&current_file_set, 1);
1544 path_list_clear(&current_directory_set, 1);
1545 get_files_dirs(head);
1546 get_files_dirs(merge);
1547
1548 entries = get_unmerged();
1549 re_head = get_renames(head, common, head, merge, entries);
1550 re_merge = get_renames(merge, common, head, merge, entries);
1551 clean = process_renames(re_head, re_merge,
1552 branch1, branch2);
1553 total_cnt += entries->nr;
1554 for (i = 0; i < entries->nr; i++, merged_cnt++) {
1555 const char *path = entries->items[i].path;
1556 struct stage_data *e = entries->items[i].util;
1557 if (!e->processed
1558 && !process_entry(path, e, branch1, branch2))
1559 clean = 0;
1560 if (do_progress)
1561 display_progress();
1562 }
1563
1564 path_list_clear(re_merge, 0);
1565 path_list_clear(re_head, 0);
1566 path_list_clear(entries, 1);
1567
1568 }
1569 else
1570 clean = 1;
1571
1572 if (index_only)
1573 *result = git_write_tree();
1574
1575 return clean;
1576 }
1577
1578 static struct commit_list *reverse_commit_list(struct commit_list *list)
1579 {
1580 struct commit_list *next = NULL, *current, *backup;
1581 for (current = list; current; current = backup) {
1582 backup = current->next;
1583 current->next = next;
1584 next = current;
1585 }
1586 return next;
1587 }
1588
1589 /*
1590 * Merge the commits h1 and h2, return the resulting virtual
1591 * commit object and a flag indicating the cleanness of the merge.
1592 */
1593 static int merge(struct commit *h1,
1594 struct commit *h2,
1595 const char *branch1,
1596 const char *branch2,
1597 struct commit_list *ca,
1598 struct commit **result)
1599 {
1600 struct commit_list *iter;
1601 struct commit *merged_common_ancestors;
1602 struct tree *mrtree;
1603 int clean;
1604
1605 if (show(4)) {
1606 output(4, "Merging:");
1607 output_commit_title(h1);
1608 output_commit_title(h2);
1609 }
1610
1611 if (!ca) {
1612 ca = get_merge_bases(h1, h2, 1);
1613 ca = reverse_commit_list(ca);
1614 }
1615
1616 if (show(5)) {
1617 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1618 for (iter = ca; iter; iter = iter->next)
1619 output_commit_title(iter->item);
1620 }
1621
1622 merged_common_ancestors = pop_commit(&ca);
1623 if (merged_common_ancestors == NULL) {
1624 /* if there is no common ancestor, make an empty tree */
1625 struct tree *tree = xcalloc(1, sizeof(struct tree));
1626
1627 tree->object.parsed = 1;
1628 tree->object.type = OBJ_TREE;
1629 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1630 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1631 }
1632
1633 for (iter = ca; iter; iter = iter->next) {
1634 call_depth++;
1635 /*
1636 * When the merge fails, the result contains files
1637 * with conflict markers. The cleanness flag is
1638 * ignored, it was never actually used, as result of
1639 * merge_trees has always overwritten it: the committed
1640 * "conflicts" were already resolved.
1641 */
1642 discard_cache();
1643 merge(merged_common_ancestors, iter->item,
1644 "Temporary merge branch 1",
1645 "Temporary merge branch 2",
1646 NULL,
1647 &merged_common_ancestors);
1648 call_depth--;
1649
1650 if (!merged_common_ancestors)
1651 die("merge returned no commit");
1652 }
1653
1654 discard_cache();
1655 if (!call_depth) {
1656 read_cache();
1657 index_only = 0;
1658 } else
1659 index_only = 1;
1660
1661 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1662 branch1, branch2, &mrtree);
1663
1664 if (index_only) {
1665 *result = make_virtual_commit(mrtree, "merged tree");
1666 commit_list_insert(h1, &(*result)->parents);
1667 commit_list_insert(h2, &(*result)->parents->next);
1668 }
1669 if (!call_depth && do_progress) {
1670 /* Make sure we end at 100% */
1671 if (!total_cnt)
1672 total_cnt = 1;
1673 merged_cnt = total_cnt;
1674 progress_update = 1;
1675 display_progress();
1676 fputc('\n', stderr);
1677 }
1678 flush_output();
1679 return clean;
1680 }
1681
1682 static const char *better_branch_name(const char *branch)
1683 {
1684 static char githead_env[8 + 40 + 1];
1685 char *name;
1686
1687 if (strlen(branch) != 40)
1688 return branch;
1689 sprintf(githead_env, "GITHEAD_%s", branch);
1690 name = getenv(githead_env);
1691 return name ? name : branch;
1692 }
1693
1694 static struct commit *get_ref(const char *ref)
1695 {
1696 unsigned char sha1[20];
1697 struct object *object;
1698
1699 if (get_sha1(ref, sha1))
1700 die("Could not resolve ref '%s'", ref);
1701 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1702 if (object->type == OBJ_TREE)
1703 return make_virtual_commit((struct tree*)object,
1704 better_branch_name(ref));
1705 if (object->type != OBJ_COMMIT)
1706 return NULL;
1707 if (parse_commit((struct commit *)object))
1708 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1709 return (struct commit *)object;
1710 }
1711
1712 static int merge_config(const char *var, const char *value)
1713 {
1714 if (!strcasecmp(var, "merge.verbosity")) {
1715 verbosity = git_config_int(var, value);
1716 return 0;
1717 }
1718 return git_default_config(var, value);
1719 }
1720
1721 int main(int argc, char *argv[])
1722 {
1723 static const char *bases[20];
1724 static unsigned bases_count = 0;
1725 int i, clean;
1726 const char *branch1, *branch2;
1727 struct commit *result, *h1, *h2;
1728 struct commit_list *ca = NULL;
1729 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1730 int index_fd;
1731
1732 if (argv[0]) {
1733 int namelen = strlen(argv[0]);
1734 if (8 < namelen &&
1735 !strcmp(argv[0] + namelen - 8, "-subtree"))
1736 subtree_merge = 1;
1737 }
1738
1739 git_config(merge_config);
1740 if (getenv("GIT_MERGE_VERBOSITY"))
1741 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1742
1743 if (argc < 4)
1744 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1745
1746 for (i = 1; i < argc; ++i) {
1747 if (!strcmp(argv[i], "--"))
1748 break;
1749 if (bases_count < sizeof(bases)/sizeof(*bases))
1750 bases[bases_count++] = argv[i];
1751 }
1752 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1753 die("Not handling anything other than two heads merge.");
1754 if (verbosity >= 5) {
1755 buffer_output = 0;
1756 do_progress = 0;
1757 }
1758 else
1759 do_progress = isatty(1);
1760
1761 branch1 = argv[++i];
1762 branch2 = argv[++i];
1763
1764 h1 = get_ref(branch1);
1765 h2 = get_ref(branch2);
1766
1767 branch1 = better_branch_name(branch1);
1768 branch2 = better_branch_name(branch2);
1769
1770 if (do_progress)
1771 setup_progress_signal();
1772 if (show(3))
1773 printf("Merging %s with %s\n", branch1, branch2);
1774
1775 index_fd = hold_locked_index(lock, 1);
1776
1777 for (i = 0; i < bases_count; i++) {
1778 struct commit *ancestor = get_ref(bases[i]);
1779 ca = commit_list_insert(ancestor, &ca);
1780 }
1781 clean = merge(h1, h2, branch1, branch2, ca, &result);
1782
1783 if (active_cache_changed &&
1784 (write_cache(index_fd, active_cache, active_nr) ||
1785 close(index_fd) || commit_locked_index(lock)))
1786 die ("unable to write %s", get_index_file());
1787
1788 return clean ? 0: 1;
1789 }
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