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Custom low-level merge driver: change the configuration scheme.
[git/gitweb.git] / merge-recursive.c
blob0f5c28eaff1ccbfd2abd288e9c72d43d86f1d20d
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 struct ll_merge_driver *next;
681 char *cmdline;
682 };
683
684 /*
685 * Built-in low-levels
686 */
687 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
688 const char *path_unused,
689 mmfile_t *orig,
690 mmfile_t *src1, const char *name1,
691 mmfile_t *src2, const char *name2,
692 mmbuffer_t *result)
693 {
694 xpparam_t xpp;
695
696 memset(&xpp, 0, sizeof(xpp));
697 return xdl_merge(orig,
698 src1, name1,
699 src2, name2,
700 &xpp, XDL_MERGE_ZEALOUS,
701 result);
702 }
703
704 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
705 const char *path_unused,
706 mmfile_t *orig,
707 mmfile_t *src1, const char *name1,
708 mmfile_t *src2, const char *name2,
709 mmbuffer_t *result)
710 {
711 char *src, *dst;
712 long size;
713 const int marker_size = 7;
714
715 int status = ll_xdl_merge(drv_unused, path_unused,
716 orig, src1, NULL, src2, NULL, result);
717 if (status <= 0)
718 return status;
719 size = result->size;
720 src = dst = result->ptr;
721 while (size) {
722 char ch;
723 if ((marker_size < size) &&
724 (*src == '<' || *src == '=' || *src == '>')) {
725 int i;
726 ch = *src;
727 for (i = 0; i < marker_size; i++)
728 if (src[i] != ch)
729 goto not_a_marker;
730 if (src[marker_size] != '\n')
731 goto not_a_marker;
732 src += marker_size + 1;
733 size -= marker_size + 1;
734 continue;
735 }
736 not_a_marker:
737 do {
738 ch = *src++;
739 *dst++ = ch;
740 size--;
741 } while (ch != '\n' && size);
742 }
743 result->size = dst - result->ptr;
744 return 0;
745 }
746
747 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
748 const char *path_unused,
749 mmfile_t *orig,
750 mmfile_t *src1, const char *name1,
751 mmfile_t *src2, const char *name2,
752 mmbuffer_t *result)
753 {
754 /*
755 * The tentative merge result is "ours" for the final round,
756 * or common ancestor for an internal merge. Still return
757 * "conflicted merge" status.
758 */
759 mmfile_t *stolen = index_only ? orig : src1;
760
761 result->ptr = stolen->ptr;
762 result->size = stolen->size;
763 stolen->ptr = NULL;
764 return 1;
765 }
766
767 #define LL_BINARY_MERGE 0
768 #define LL_TEXT_MERGE 1
769 #define LL_UNION_MERGE 2
770 static struct ll_merge_driver ll_merge_drv[] = {
771 { "binary", "built-in binary merge", ll_binary_merge },
772 { "text", "built-in 3-way text merge", ll_xdl_merge },
773 { "union", "built-in union merge", ll_union_merge },
774 };
775
776 static void create_temp(mmfile_t *src, char *path)
777 {
778 int fd;
779
780 strcpy(path, ".merge_file_XXXXXX");
781 fd = mkstemp(path);
782 if (fd < 0)
783 die("unable to create temp-file");
784 if (write_in_full(fd, src->ptr, src->size) != src->size)
785 die("unable to write temp-file");
786 close(fd);
787 }
788
789 /*
790 * User defined low-level merge driver support.
791 */
792 static int ll_ext_merge(const struct ll_merge_driver *fn,
793 const char *path,
794 mmfile_t *orig,
795 mmfile_t *src1, const char *name1,
796 mmfile_t *src2, const char *name2,
797 mmbuffer_t *result)
798 {
799 char temp[3][50];
800 char cmdbuf[2048];
801 struct interp table[] = {
802 { "%O" },
803 { "%A" },
804 { "%B" },
805 };
806 struct child_process child;
807 const char *args[20];
808 int status, fd, i;
809 struct stat st;
810
811 result->ptr = NULL;
812 result->size = 0;
813 create_temp(orig, temp[0]);
814 create_temp(src1, temp[1]);
815 create_temp(src2, temp[2]);
816
817 interp_set_entry(table, 0, temp[0]);
818 interp_set_entry(table, 1, temp[1]);
819 interp_set_entry(table, 2, temp[2]);
820
821 output(1, "merging %s using %s", path,
822 fn->description ? fn->description : fn->name);
823
824 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
825
826 memset(&child, 0, sizeof(child));
827 child.argv = args;
828 args[0] = "sh";
829 args[1] = "-c";
830 args[2] = cmdbuf;
831 args[3] = NULL;
832
833 status = run_command(&child);
834 if (status < -ERR_RUN_COMMAND_FORK)
835 ; /* failure in run-command */
836 else
837 status = -status;
838 fd = open(temp[1], O_RDONLY);
839 if (fd < 0)
840 goto bad;
841 if (fstat(fd, &st))
842 goto close_bad;
843 result->size = st.st_size;
844 result->ptr = xmalloc(result->size + 1);
845 if (read_in_full(fd, result->ptr, result->size) != result->size) {
846 free(result->ptr);
847 result->ptr = NULL;
848 result->size = 0;
849 }
850 close_bad:
851 close(fd);
852 bad:
853 for (i = 0; i < 3; i++)
854 unlink(temp[i]);
855 return status;
856 }
857
858 /*
859 * merge.default and merge.driver configuration items
860 */
861 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
862 static const char *default_ll_merge;
863
864 static int read_merge_config(const char *var, const char *value)
865 {
866 struct ll_merge_driver *fn;
867 const char *ep, *name;
868 int namelen;
869
870 if (!strcmp(var, "merge.default")) {
871 if (value)
872 default_ll_merge = strdup(value);
873 return 0;
874 }
875
876 /*
877 * We are not interested in anything but "merge.<name>.variable";
878 * especially, we do not want to look at variables such as
879 * "merge.summary", "merge.tool", and "merge.verbosity".
880 */
881 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 6)
882 return 0;
883
884 /*
885 * Find existing one as we might be processing merge.<name>.var2
886 * after seeing merge.<name>.var1.
887 */
888 name = var + 6;
889 namelen = ep - name;
890 for (fn = ll_user_merge; fn; fn = fn->next)
891 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
892 break;
893 if (!fn) {
894 char *namebuf;
895 fn = xcalloc(1, sizeof(struct ll_merge_driver));
896 namebuf = xmalloc(namelen + 1);
897 memcpy(namebuf, name, namelen);
898 namebuf[namelen] = 0;
899 fn->name = namebuf;
900 fn->fn = ll_ext_merge;
901 fn->next = *ll_user_merge_tail;
902 *ll_user_merge_tail = fn;
903 }
904
905 ep++;
906
907 if (!strcmp("name", ep)) {
908 if (!value)
909 return error("%s: lacks value", var);
910 fn->description = strdup(value);
911 return 0;
912 }
913
914 if (!strcmp("driver", ep)) {
915 if (!value)
916 return error("%s: lacks value", var);
917 /*
918 * merge.<name>.driver specifies the command line:
919 *
920 * command-line
921 *
922 * The command-line will be interpolated with the following
923 * tokens and is given to the shell:
924 *
925 * %O - temporary file name for the merge base.
926 * %A - temporary file name for our version.
927 * %B - temporary file name for the other branches' version.
928 *
929 * The external merge driver should write the results in the
930 * file named by %A, and signal that it has done with zero exit
931 * status.
932 */
933 fn->cmdline = strdup(value);
934 return 0;
935 }
936
937 return 0;
938 }
939
940 static void initialize_ll_merge(void)
941 {
942 if (ll_user_merge_tail)
943 return;
944 ll_user_merge_tail = &ll_user_merge;
945 git_config(read_merge_config);
946 }
947
948 static const struct ll_merge_driver *find_ll_merge_driver(void *merge_attr)
949 {
950 struct ll_merge_driver *fn;
951 const char *name;
952 int i;
953
954 initialize_ll_merge();
955
956 if (ATTR_TRUE(merge_attr))
957 return &ll_merge_drv[LL_TEXT_MERGE];
958 else if (ATTR_FALSE(merge_attr))
959 return &ll_merge_drv[LL_BINARY_MERGE];
960 else if (ATTR_UNSET(merge_attr)) {
961 if (!default_ll_merge)
962 return &ll_merge_drv[LL_TEXT_MERGE];
963 else
964 name = default_ll_merge;
965 }
966 else
967 name = merge_attr;
968
969 for (fn = ll_user_merge; fn; fn = fn->next)
970 if (!strcmp(fn->name, name))
971 return fn;
972
973 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
974 if (!strcmp(ll_merge_drv[i].name, name))
975 return &ll_merge_drv[i];
976
977 /* default to the 3-way */
978 return &ll_merge_drv[LL_TEXT_MERGE];
979 }
980
981 static void *git_path_check_merge(const char *path)
982 {
983 static struct git_attr_check attr_merge_check;
984
985 if (!attr_merge_check.attr)
986 attr_merge_check.attr = git_attr("merge", 5);
987
988 if (git_checkattr(path, 1, &attr_merge_check))
989 return ATTR__UNSET;
990 return attr_merge_check.value;
991 }
992
993 static int ll_merge(mmbuffer_t *result_buf,
994 struct diff_filespec *o,
995 struct diff_filespec *a,
996 struct diff_filespec *b,
997 const char *branch1,
998 const char *branch2)
999 {
1000 mmfile_t orig, src1, src2;
1001 char *name1, *name2;
1002 int merge_status;
1003 void *merge_attr;
1004 const struct ll_merge_driver *driver;
1005
1006 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1007 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1008
1009 fill_mm(o->sha1, &orig);
1010 fill_mm(a->sha1, &src1);
1011 fill_mm(b->sha1, &src2);
1012
1013 merge_attr = git_path_check_merge(a->path);
1014 driver = find_ll_merge_driver(merge_attr);
1015
1016 merge_status = driver->fn(driver, a->path,
1017 &orig, &src1, name1, &src2, name2,
1018 result_buf);
1019
1020 free(name1);
1021 free(name2);
1022 free(orig.ptr);
1023 free(src1.ptr);
1024 free(src2.ptr);
1025 return merge_status;
1026 }
1027
1028 static struct merge_file_info merge_file(struct diff_filespec *o,
1029 struct diff_filespec *a, struct diff_filespec *b,
1030 const char *branch1, const char *branch2)
1031 {
1032 struct merge_file_info result;
1033 result.merge = 0;
1034 result.clean = 1;
1035
1036 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1037 result.clean = 0;
1038 if (S_ISREG(a->mode)) {
1039 result.mode = a->mode;
1040 hashcpy(result.sha, a->sha1);
1041 } else {
1042 result.mode = b->mode;
1043 hashcpy(result.sha, b->sha1);
1044 }
1045 } else {
1046 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1047 result.merge = 1;
1048
1049 result.mode = a->mode == o->mode ? b->mode: a->mode;
1050
1051 if (sha_eq(a->sha1, o->sha1))
1052 hashcpy(result.sha, b->sha1);
1053 else if (sha_eq(b->sha1, o->sha1))
1054 hashcpy(result.sha, a->sha1);
1055 else if (S_ISREG(a->mode)) {
1056 mmbuffer_t result_buf;
1057 int merge_status;
1058
1059 merge_status = ll_merge(&result_buf, o, a, b,
1060 branch1, branch2);
1061
1062 if ((merge_status < 0) || !result_buf.ptr)
1063 die("Failed to execute internal merge");
1064
1065 if (write_sha1_file(result_buf.ptr, result_buf.size,
1066 blob_type, result.sha))
1067 die("Unable to add %s to database",
1068 a->path);
1069
1070 free(result_buf.ptr);
1071 result.clean = (merge_status == 0);
1072 } else {
1073 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1074 die("cannot merge modes?");
1075
1076 hashcpy(result.sha, a->sha1);
1077
1078 if (!sha_eq(a->sha1, b->sha1))
1079 result.clean = 0;
1080 }
1081 }
1082
1083 return result;
1084 }
1085
1086 static void conflict_rename_rename(struct rename *ren1,
1087 const char *branch1,
1088 struct rename *ren2,
1089 const char *branch2)
1090 {
1091 char *del[2];
1092 int delp = 0;
1093 const char *ren1_dst = ren1->pair->two->path;
1094 const char *ren2_dst = ren2->pair->two->path;
1095 const char *dst_name1 = ren1_dst;
1096 const char *dst_name2 = ren2_dst;
1097 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1098 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1099 output(1, "%s is a directory in %s added as %s instead",
1100 ren1_dst, branch2, dst_name1);
1101 remove_file(0, ren1_dst, 0);
1102 }
1103 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1104 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1105 output(1, "%s is a directory in %s added as %s instead",
1106 ren2_dst, branch1, dst_name2);
1107 remove_file(0, ren2_dst, 0);
1108 }
1109 if (index_only) {
1110 remove_file_from_cache(dst_name1);
1111 remove_file_from_cache(dst_name2);
1112 /*
1113 * Uncomment to leave the conflicting names in the resulting tree
1114 *
1115 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1116 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1117 */
1118 } else {
1119 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1120 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1121 }
1122 while (delp--)
1123 free(del[delp]);
1124 }
1125
1126 static void conflict_rename_dir(struct rename *ren1,
1127 const char *branch1)
1128 {
1129 char *new_path = unique_path(ren1->pair->two->path, branch1);
1130 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1131 remove_file(0, ren1->pair->two->path, 0);
1132 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1133 free(new_path);
1134 }
1135
1136 static void conflict_rename_rename_2(struct rename *ren1,
1137 const char *branch1,
1138 struct rename *ren2,
1139 const char *branch2)
1140 {
1141 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1142 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1143 output(1, "Renamed %s to %s and %s to %s instead",
1144 ren1->pair->one->path, new_path1,
1145 ren2->pair->one->path, new_path2);
1146 remove_file(0, ren1->pair->two->path, 0);
1147 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1148 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1149 free(new_path2);
1150 free(new_path1);
1151 }
1152
1153 static int process_renames(struct path_list *a_renames,
1154 struct path_list *b_renames,
1155 const char *a_branch,
1156 const char *b_branch)
1157 {
1158 int clean_merge = 1, i, j;
1159 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1160 const struct rename *sre;
1161
1162 for (i = 0; i < a_renames->nr; i++) {
1163 sre = a_renames->items[i].util;
1164 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1165 = sre->dst_entry;
1166 }
1167 for (i = 0; i < b_renames->nr; i++) {
1168 sre = b_renames->items[i].util;
1169 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1170 = sre->dst_entry;
1171 }
1172
1173 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1174 int compare;
1175 char *src;
1176 struct path_list *renames1, *renames2, *renames2Dst;
1177 struct rename *ren1 = NULL, *ren2 = NULL;
1178 const char *branch1, *branch2;
1179 const char *ren1_src, *ren1_dst;
1180
1181 if (i >= a_renames->nr) {
1182 compare = 1;
1183 ren2 = b_renames->items[j++].util;
1184 } else if (j >= b_renames->nr) {
1185 compare = -1;
1186 ren1 = a_renames->items[i++].util;
1187 } else {
1188 compare = strcmp(a_renames->items[i].path,
1189 b_renames->items[j].path);
1190 if (compare <= 0)
1191 ren1 = a_renames->items[i++].util;
1192 if (compare >= 0)
1193 ren2 = b_renames->items[j++].util;
1194 }
1195
1196 /* TODO: refactor, so that 1/2 are not needed */
1197 if (ren1) {
1198 renames1 = a_renames;
1199 renames2 = b_renames;
1200 renames2Dst = &b_by_dst;
1201 branch1 = a_branch;
1202 branch2 = b_branch;
1203 } else {
1204 struct rename *tmp;
1205 renames1 = b_renames;
1206 renames2 = a_renames;
1207 renames2Dst = &a_by_dst;
1208 branch1 = b_branch;
1209 branch2 = a_branch;
1210 tmp = ren2;
1211 ren2 = ren1;
1212 ren1 = tmp;
1213 }
1214 src = ren1->pair->one->path;
1215
1216 ren1->dst_entry->processed = 1;
1217 ren1->src_entry->processed = 1;
1218
1219 if (ren1->processed)
1220 continue;
1221 ren1->processed = 1;
1222
1223 ren1_src = ren1->pair->one->path;
1224 ren1_dst = ren1->pair->two->path;
1225
1226 if (ren2) {
1227 const char *ren2_src = ren2->pair->one->path;
1228 const char *ren2_dst = ren2->pair->two->path;
1229 /* Renamed in 1 and renamed in 2 */
1230 if (strcmp(ren1_src, ren2_src) != 0)
1231 die("ren1.src != ren2.src");
1232 ren2->dst_entry->processed = 1;
1233 ren2->processed = 1;
1234 if (strcmp(ren1_dst, ren2_dst) != 0) {
1235 clean_merge = 0;
1236 output(1, "CONFLICT (rename/rename): "
1237 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1238 "rename \"%s\"->\"%s\" in \"%s\"%s",
1239 src, ren1_dst, branch1,
1240 src, ren2_dst, branch2,
1241 index_only ? " (left unresolved)": "");
1242 if (index_only) {
1243 remove_file_from_cache(src);
1244 update_file(0, ren1->pair->one->sha1,
1245 ren1->pair->one->mode, src);
1246 }
1247 conflict_rename_rename(ren1, branch1, ren2, branch2);
1248 } else {
1249 struct merge_file_info mfi;
1250 remove_file(1, ren1_src, 1);
1251 mfi = merge_file(ren1->pair->one,
1252 ren1->pair->two,
1253 ren2->pair->two,
1254 branch1,
1255 branch2);
1256 if (mfi.merge || !mfi.clean)
1257 output(1, "Renamed %s->%s", src, ren1_dst);
1258
1259 if (mfi.merge)
1260 output(2, "Auto-merged %s", ren1_dst);
1261
1262 if (!mfi.clean) {
1263 output(1, "CONFLICT (content): merge conflict in %s",
1264 ren1_dst);
1265 clean_merge = 0;
1266
1267 if (!index_only)
1268 update_stages(ren1_dst,
1269 ren1->pair->one,
1270 ren1->pair->two,
1271 ren2->pair->two,
1272 1 /* clear */);
1273 }
1274 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1275 }
1276 } else {
1277 /* Renamed in 1, maybe changed in 2 */
1278 struct path_list_item *item;
1279 /* we only use sha1 and mode of these */
1280 struct diff_filespec src_other, dst_other;
1281 int try_merge, stage = a_renames == renames1 ? 3: 2;
1282
1283 remove_file(1, ren1_src, index_only || stage == 3);
1284
1285 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1286 src_other.mode = ren1->src_entry->stages[stage].mode;
1287 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1288 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1289
1290 try_merge = 0;
1291
1292 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1293 clean_merge = 0;
1294 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1295 " directory %s added in %s",
1296 ren1_src, ren1_dst, branch1,
1297 ren1_dst, branch2);
1298 conflict_rename_dir(ren1, branch1);
1299 } else if (sha_eq(src_other.sha1, null_sha1)) {
1300 clean_merge = 0;
1301 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1302 "and deleted in %s",
1303 ren1_src, ren1_dst, branch1,
1304 branch2);
1305 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1306 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1307 const char *new_path;
1308 clean_merge = 0;
1309 try_merge = 1;
1310 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1311 "%s added in %s",
1312 ren1_src, ren1_dst, branch1,
1313 ren1_dst, branch2);
1314 new_path = unique_path(ren1_dst, branch2);
1315 output(1, "Added as %s instead", new_path);
1316 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1317 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1318 ren2 = item->util;
1319 clean_merge = 0;
1320 ren2->processed = 1;
1321 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1322 "Renamed %s->%s in %s",
1323 ren1_src, ren1_dst, branch1,
1324 ren2->pair->one->path, ren2->pair->two->path, branch2);
1325 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1326 } else
1327 try_merge = 1;
1328
1329 if (try_merge) {
1330 struct diff_filespec *o, *a, *b;
1331 struct merge_file_info mfi;
1332 src_other.path = (char *)ren1_src;
1333
1334 o = ren1->pair->one;
1335 if (a_renames == renames1) {
1336 a = ren1->pair->two;
1337 b = &src_other;
1338 } else {
1339 b = ren1->pair->two;
1340 a = &src_other;
1341 }
1342 mfi = merge_file(o, a, b,
1343 a_branch, b_branch);
1344
1345 if (mfi.merge || !mfi.clean)
1346 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1347 if (mfi.merge)
1348 output(2, "Auto-merged %s", ren1_dst);
1349 if (!mfi.clean) {
1350 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1351 ren1_dst);
1352 clean_merge = 0;
1353
1354 if (!index_only)
1355 update_stages(ren1_dst,
1356 o, a, b, 1);
1357 }
1358 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1359 }
1360 }
1361 }
1362 path_list_clear(&a_by_dst, 0);
1363 path_list_clear(&b_by_dst, 0);
1364
1365 return clean_merge;
1366 }
1367
1368 static unsigned char *has_sha(const unsigned char *sha)
1369 {
1370 return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
1371 }
1372
1373 /* Per entry merge function */
1374 static int process_entry(const char *path, struct stage_data *entry,
1375 const char *branch1,
1376 const char *branch2)
1377 {
1378 /*
1379 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1380 print_index_entry("\tpath: ", entry);
1381 */
1382 int clean_merge = 1;
1383 unsigned char *o_sha = has_sha(entry->stages[1].sha);
1384 unsigned char *a_sha = has_sha(entry->stages[2].sha);
1385 unsigned char *b_sha = has_sha(entry->stages[3].sha);
1386 unsigned o_mode = entry->stages[1].mode;
1387 unsigned a_mode = entry->stages[2].mode;
1388 unsigned b_mode = entry->stages[3].mode;
1389
1390 if (o_sha && (!a_sha || !b_sha)) {
1391 /* Case A: Deleted in one */
1392 if ((!a_sha && !b_sha) ||
1393 (sha_eq(a_sha, o_sha) && !b_sha) ||
1394 (!a_sha && sha_eq(b_sha, o_sha))) {
1395 /* Deleted in both or deleted in one and
1396 * unchanged in the other */
1397 if (a_sha)
1398 output(2, "Removed %s", path);
1399 /* do not touch working file if it did not exist */
1400 remove_file(1, path, !a_sha);
1401 } else {
1402 /* Deleted in one and changed in the other */
1403 clean_merge = 0;
1404 if (!a_sha) {
1405 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1406 "and modified in %s. Version %s of %s left in tree.",
1407 path, branch1,
1408 branch2, branch2, path);
1409 update_file(0, b_sha, b_mode, path);
1410 } else {
1411 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1412 "and modified in %s. Version %s of %s left in tree.",
1413 path, branch2,
1414 branch1, branch1, path);
1415 update_file(0, a_sha, a_mode, path);
1416 }
1417 }
1418
1419 } else if ((!o_sha && a_sha && !b_sha) ||
1420 (!o_sha && !a_sha && b_sha)) {
1421 /* Case B: Added in one. */
1422 const char *add_branch;
1423 const char *other_branch;
1424 unsigned mode;
1425 const unsigned char *sha;
1426 const char *conf;
1427
1428 if (a_sha) {
1429 add_branch = branch1;
1430 other_branch = branch2;
1431 mode = a_mode;
1432 sha = a_sha;
1433 conf = "file/directory";
1434 } else {
1435 add_branch = branch2;
1436 other_branch = branch1;
1437 mode = b_mode;
1438 sha = b_sha;
1439 conf = "directory/file";
1440 }
1441 if (path_list_has_path(&current_directory_set, path)) {
1442 const char *new_path = unique_path(path, add_branch);
1443 clean_merge = 0;
1444 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1445 "Added %s as %s",
1446 conf, path, other_branch, path, new_path);
1447 remove_file(0, path, 0);
1448 update_file(0, sha, mode, new_path);
1449 } else {
1450 output(2, "Added %s", path);
1451 update_file(1, sha, mode, path);
1452 }
1453 } else if (a_sha && b_sha) {
1454 /* Case C: Added in both (check for same permissions) and */
1455 /* case D: Modified in both, but differently. */
1456 const char *reason = "content";
1457 struct merge_file_info mfi;
1458 struct diff_filespec o, a, b;
1459
1460 if (!o_sha) {
1461 reason = "add/add";
1462 o_sha = (unsigned char *)null_sha1;
1463 }
1464 output(2, "Auto-merged %s", path);
1465 o.path = a.path = b.path = (char *)path;
1466 hashcpy(o.sha1, o_sha);
1467 o.mode = o_mode;
1468 hashcpy(a.sha1, a_sha);
1469 a.mode = a_mode;
1470 hashcpy(b.sha1, b_sha);
1471 b.mode = b_mode;
1472
1473 mfi = merge_file(&o, &a, &b,
1474 branch1, branch2);
1475
1476 if (mfi.clean)
1477 update_file(1, mfi.sha, mfi.mode, path);
1478 else {
1479 clean_merge = 0;
1480 output(1, "CONFLICT (%s): Merge conflict in %s",
1481 reason, path);
1482
1483 if (index_only)
1484 update_file(0, mfi.sha, mfi.mode, path);
1485 else
1486 update_file_flags(mfi.sha, mfi.mode, path,
1487 0 /* update_cache */, 1 /* update_working_directory */);
1488 }
1489 } else
1490 die("Fatal merge failure, shouldn't happen.");
1491
1492 return clean_merge;
1493 }
1494
1495 static int merge_trees(struct tree *head,
1496 struct tree *merge,
1497 struct tree *common,
1498 const char *branch1,
1499 const char *branch2,
1500 struct tree **result)
1501 {
1502 int code, clean;
1503
1504 if (subtree_merge) {
1505 merge = shift_tree_object(head, merge);
1506 common = shift_tree_object(head, common);
1507 }
1508
1509 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1510 output(0, "Already uptodate!");
1511 *result = head;
1512 return 1;
1513 }
1514
1515 code = git_merge_trees(index_only, common, head, merge);
1516
1517 if (code != 0)
1518 die("merging of trees %s and %s failed",
1519 sha1_to_hex(head->object.sha1),
1520 sha1_to_hex(merge->object.sha1));
1521
1522 if (unmerged_index()) {
1523 struct path_list *entries, *re_head, *re_merge;
1524 int i;
1525 path_list_clear(&current_file_set, 1);
1526 path_list_clear(&current_directory_set, 1);
1527 get_files_dirs(head);
1528 get_files_dirs(merge);
1529
1530 entries = get_unmerged();
1531 re_head = get_renames(head, common, head, merge, entries);
1532 re_merge = get_renames(merge, common, head, merge, entries);
1533 clean = process_renames(re_head, re_merge,
1534 branch1, branch2);
1535 total_cnt += entries->nr;
1536 for (i = 0; i < entries->nr; i++, merged_cnt++) {
1537 const char *path = entries->items[i].path;
1538 struct stage_data *e = entries->items[i].util;
1539 if (!e->processed
1540 && !process_entry(path, e, branch1, branch2))
1541 clean = 0;
1542 if (do_progress)
1543 display_progress();
1544 }
1545
1546 path_list_clear(re_merge, 0);
1547 path_list_clear(re_head, 0);
1548 path_list_clear(entries, 1);
1549
1550 }
1551 else
1552 clean = 1;
1553
1554 if (index_only)
1555 *result = git_write_tree();
1556
1557 return clean;
1558 }
1559
1560 static struct commit_list *reverse_commit_list(struct commit_list *list)
1561 {
1562 struct commit_list *next = NULL, *current, *backup;
1563 for (current = list; current; current = backup) {
1564 backup = current->next;
1565 current->next = next;
1566 next = current;
1567 }
1568 return next;
1569 }
1570
1571 /*
1572 * Merge the commits h1 and h2, return the resulting virtual
1573 * commit object and a flag indicating the cleanness of the merge.
1574 */
1575 static int merge(struct commit *h1,
1576 struct commit *h2,
1577 const char *branch1,
1578 const char *branch2,
1579 struct commit_list *ca,
1580 struct commit **result)
1581 {
1582 struct commit_list *iter;
1583 struct commit *merged_common_ancestors;
1584 struct tree *mrtree;
1585 int clean;
1586
1587 if (show(4)) {
1588 output(4, "Merging:");
1589 output_commit_title(h1);
1590 output_commit_title(h2);
1591 }
1592
1593 if (!ca) {
1594 ca = get_merge_bases(h1, h2, 1);
1595 ca = reverse_commit_list(ca);
1596 }
1597
1598 if (show(5)) {
1599 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1600 for (iter = ca; iter; iter = iter->next)
1601 output_commit_title(iter->item);
1602 }
1603
1604 merged_common_ancestors = pop_commit(&ca);
1605 if (merged_common_ancestors == NULL) {
1606 /* if there is no common ancestor, make an empty tree */
1607 struct tree *tree = xcalloc(1, sizeof(struct tree));
1608
1609 tree->object.parsed = 1;
1610 tree->object.type = OBJ_TREE;
1611 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1612 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1613 }
1614
1615 for (iter = ca; iter; iter = iter->next) {
1616 call_depth++;
1617 /*
1618 * When the merge fails, the result contains files
1619 * with conflict markers. The cleanness flag is
1620 * ignored, it was never actually used, as result of
1621 * merge_trees has always overwritten it: the committed
1622 * "conflicts" were already resolved.
1623 */
1624 discard_cache();
1625 merge(merged_common_ancestors, iter->item,
1626 "Temporary merge branch 1",
1627 "Temporary merge branch 2",
1628 NULL,
1629 &merged_common_ancestors);
1630 call_depth--;
1631
1632 if (!merged_common_ancestors)
1633 die("merge returned no commit");
1634 }
1635
1636 discard_cache();
1637 if (!call_depth) {
1638 read_cache();
1639 index_only = 0;
1640 } else
1641 index_only = 1;
1642
1643 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1644 branch1, branch2, &mrtree);
1645
1646 if (index_only) {
1647 *result = make_virtual_commit(mrtree, "merged tree");
1648 commit_list_insert(h1, &(*result)->parents);
1649 commit_list_insert(h2, &(*result)->parents->next);
1650 }
1651 if (!call_depth && do_progress) {
1652 /* Make sure we end at 100% */
1653 if (!total_cnt)
1654 total_cnt = 1;
1655 merged_cnt = total_cnt;
1656 progress_update = 1;
1657 display_progress();
1658 fputc('\n', stderr);
1659 }
1660 flush_output();
1661 return clean;
1662 }
1663
1664 static const char *better_branch_name(const char *branch)
1665 {
1666 static char githead_env[8 + 40 + 1];
1667 char *name;
1668
1669 if (strlen(branch) != 40)
1670 return branch;
1671 sprintf(githead_env, "GITHEAD_%s", branch);
1672 name = getenv(githead_env);
1673 return name ? name : branch;
1674 }
1675
1676 static struct commit *get_ref(const char *ref)
1677 {
1678 unsigned char sha1[20];
1679 struct object *object;
1680
1681 if (get_sha1(ref, sha1))
1682 die("Could not resolve ref '%s'", ref);
1683 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1684 if (object->type == OBJ_TREE)
1685 return make_virtual_commit((struct tree*)object,
1686 better_branch_name(ref));
1687 if (object->type != OBJ_COMMIT)
1688 return NULL;
1689 if (parse_commit((struct commit *)object))
1690 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1691 return (struct commit *)object;
1692 }
1693
1694 static int merge_config(const char *var, const char *value)
1695 {
1696 if (!strcasecmp(var, "merge.verbosity")) {
1697 verbosity = git_config_int(var, value);
1698 return 0;
1699 }
1700 return git_default_config(var, value);
1701 }
1702
1703 int main(int argc, char *argv[])
1704 {
1705 static const char *bases[20];
1706 static unsigned bases_count = 0;
1707 int i, clean;
1708 const char *branch1, *branch2;
1709 struct commit *result, *h1, *h2;
1710 struct commit_list *ca = NULL;
1711 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1712 int index_fd;
1713
1714 if (argv[0]) {
1715 int namelen = strlen(argv[0]);
1716 if (8 < namelen &&
1717 !strcmp(argv[0] + namelen - 8, "-subtree"))
1718 subtree_merge = 1;
1719 }
1720
1721 git_config(merge_config);
1722 if (getenv("GIT_MERGE_VERBOSITY"))
1723 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1724
1725 if (argc < 4)
1726 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1727
1728 for (i = 1; i < argc; ++i) {
1729 if (!strcmp(argv[i], "--"))
1730 break;
1731 if (bases_count < sizeof(bases)/sizeof(*bases))
1732 bases[bases_count++] = argv[i];
1733 }
1734 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1735 die("Not handling anything other than two heads merge.");
1736 if (verbosity >= 5) {
1737 buffer_output = 0;
1738 do_progress = 0;
1739 }
1740 else
1741 do_progress = isatty(1);
1742
1743 branch1 = argv[++i];
1744 branch2 = argv[++i];
1745
1746 h1 = get_ref(branch1);
1747 h2 = get_ref(branch2);
1748
1749 branch1 = better_branch_name(branch1);
1750 branch2 = better_branch_name(branch2);
1751
1752 if (do_progress)
1753 setup_progress_signal();
1754 if (show(3))
1755 printf("Merging %s with %s\n", branch1, branch2);
1756
1757 index_fd = hold_locked_index(lock, 1);
1758
1759 for (i = 0; i < bases_count; i++) {
1760 struct commit *ancestor = get_ref(bases[i]);
1761 ca = commit_list_insert(ancestor, &ca);
1762 }
1763 clean = merge(h1, h2, branch1, branch2, ca, &result);
1764
1765 if (active_cache_changed &&
1766 (write_cache(index_fd, active_cache, active_nr) ||
1767 close(index_fd) || commit_locked_index(lock)))
1768 die ("unable to write %s", get_index_file());
1769
1770 return clean ? 0: 1;
1771 }
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