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user-manual: move packfile and dangling object discussion
[git/jrn.git] / merge-recursive.c
blob16f6a0f98b5df8fbb9bb5263d0d32afca678cbec
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 struct output_buffer *output_list, *output_end;
101
102 static int show (int v)
103 {
104 return (!call_depth && verbosity >= v) || verbosity >= 5;
105 }
106
107 static void output(int v, const char *fmt, ...)
108 {
109 va_list args;
110 va_start(args, fmt);
111 if (buffer_output && show(v)) {
112 struct output_buffer *b = xmalloc(sizeof(*b));
113 nfvasprintf(&b->str, fmt, args);
114 b->next = NULL;
115 if (output_end)
116 output_end->next = b;
117 else
118 output_list = b;
119 output_end = b;
120 } else if (show(v)) {
121 int i;
122 for (i = call_depth; i--;)
123 fputs(" ", stdout);
124 vfprintf(stdout, fmt, args);
125 fputc('\n', stdout);
126 }
127 va_end(args);
128 }
129
130 static void flush_output(void)
131 {
132 struct output_buffer *b, *n;
133 for (b = output_list; b; b = n) {
134 int i;
135 for (i = call_depth; i--;)
136 fputs(" ", stdout);
137 fputs(b->str, stdout);
138 fputc('\n', stdout);
139 n = b->next;
140 free(b->str);
141 free(b);
142 }
143 output_list = NULL;
144 output_end = NULL;
145 }
146
147 static void output_commit_title(struct commit *commit)
148 {
149 int i;
150 flush_output();
151 for (i = call_depth; i--;)
152 fputs(" ", stdout);
153 if (commit->util)
154 printf("virtual %s\n", (char *)commit->util);
155 else {
156 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
157 if (parse_commit(commit) != 0)
158 printf("(bad commit)\n");
159 else {
160 const char *s;
161 int len;
162 for (s = commit->buffer; *s; s++)
163 if (*s == '\n' && s[1] == '\n') {
164 s += 2;
165 break;
166 }
167 for (len = 0; s[len] && '\n' != s[len]; len++)
168 ; /* do nothing */
169 printf("%.*s\n", len, s);
170 }
171 }
172 }
173
174 static struct cache_entry *make_cache_entry(unsigned int mode,
175 const unsigned char *sha1, const char *path, int stage, int refresh)
176 {
177 int size, len;
178 struct cache_entry *ce;
179
180 if (!verify_path(path))
181 return NULL;
182
183 len = strlen(path);
184 size = cache_entry_size(len);
185 ce = xcalloc(1, size);
186
187 hashcpy(ce->sha1, sha1);
188 memcpy(ce->name, path, len);
189 ce->ce_flags = create_ce_flags(len, stage);
190 ce->ce_mode = create_ce_mode(mode);
191
192 if (refresh)
193 return refresh_cache_entry(ce, 0);
194
195 return ce;
196 }
197
198 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
199 const char *path, int stage, int refresh, int options)
200 {
201 struct cache_entry *ce;
202 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
203 if (!ce)
204 return error("addinfo_cache failed for path '%s'", path);
205 return add_cache_entry(ce, options);
206 }
207
208 /*
209 * This is a global variable which is used in a number of places but
210 * only written to in the 'merge' function.
211 *
212 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
213 * don't update the working directory.
214 * 0 => Leave unmerged entries in the cache and update
215 * the working directory.
216 */
217 static int index_only = 0;
218
219 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
220 {
221 parse_tree(tree);
222 init_tree_desc(desc, tree->buffer, tree->size);
223 }
224
225 static int git_merge_trees(int index_only,
226 struct tree *common,
227 struct tree *head,
228 struct tree *merge)
229 {
230 int rc;
231 struct tree_desc t[3];
232 struct unpack_trees_options opts;
233
234 memset(&opts, 0, sizeof(opts));
235 if (index_only)
236 opts.index_only = 1;
237 else
238 opts.update = 1;
239 opts.merge = 1;
240 opts.head_idx = 2;
241 opts.fn = threeway_merge;
242
243 init_tree_desc_from_tree(t+0, common);
244 init_tree_desc_from_tree(t+1, head);
245 init_tree_desc_from_tree(t+2, merge);
246
247 rc = unpack_trees(3, t, &opts);
248 cache_tree_free(&active_cache_tree);
249 return rc;
250 }
251
252 static int unmerged_index(void)
253 {
254 int i;
255 for (i = 0; i < active_nr; i++) {
256 struct cache_entry *ce = active_cache[i];
257 if (ce_stage(ce))
258 return 1;
259 }
260 return 0;
261 }
262
263 static struct tree *git_write_tree(void)
264 {
265 struct tree *result = NULL;
266
267 if (unmerged_index()) {
268 int i;
269 output(0, "There are unmerged index entries:");
270 for (i = 0; i < active_nr; i++) {
271 struct cache_entry *ce = active_cache[i];
272 if (ce_stage(ce))
273 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
274 }
275 return NULL;
276 }
277
278 if (!active_cache_tree)
279 active_cache_tree = cache_tree();
280
281 if (!cache_tree_fully_valid(active_cache_tree) &&
282 cache_tree_update(active_cache_tree,
283 active_cache, active_nr, 0, 0) < 0)
284 die("error building trees");
285
286 result = lookup_tree(active_cache_tree->sha1);
287
288 return result;
289 }
290
291 static int save_files_dirs(const unsigned char *sha1,
292 const char *base, int baselen, const char *path,
293 unsigned int mode, int stage)
294 {
295 int len = strlen(path);
296 char *newpath = xmalloc(baselen + len + 1);
297 memcpy(newpath, base, baselen);
298 memcpy(newpath + baselen, path, len);
299 newpath[baselen + len] = '\0';
300
301 if (S_ISDIR(mode))
302 path_list_insert(newpath, &current_directory_set);
303 else
304 path_list_insert(newpath, &current_file_set);
305 free(newpath);
306
307 return READ_TREE_RECURSIVE;
308 }
309
310 static int get_files_dirs(struct tree *tree)
311 {
312 int n;
313 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
314 return 0;
315 n = current_file_set.nr + current_directory_set.nr;
316 return n;
317 }
318
319 /*
320 * Returns a index_entry instance which doesn't have to correspond to
321 * a real cache entry in Git's index.
322 */
323 static struct stage_data *insert_stage_data(const char *path,
324 struct tree *o, struct tree *a, struct tree *b,
325 struct path_list *entries)
326 {
327 struct path_list_item *item;
328 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
329 get_tree_entry(o->object.sha1, path,
330 e->stages[1].sha, &e->stages[1].mode);
331 get_tree_entry(a->object.sha1, path,
332 e->stages[2].sha, &e->stages[2].mode);
333 get_tree_entry(b->object.sha1, path,
334 e->stages[3].sha, &e->stages[3].mode);
335 item = path_list_insert(path, entries);
336 item->util = e;
337 return e;
338 }
339
340 /*
341 * Create a dictionary mapping file names to stage_data objects. The
342 * dictionary contains one entry for every path with a non-zero stage entry.
343 */
344 static struct path_list *get_unmerged(void)
345 {
346 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
347 int i;
348
349 unmerged->strdup_paths = 1;
350
351 for (i = 0; i < active_nr; i++) {
352 struct path_list_item *item;
353 struct stage_data *e;
354 struct cache_entry *ce = active_cache[i];
355 if (!ce_stage(ce))
356 continue;
357
358 item = path_list_lookup(ce->name, unmerged);
359 if (!item) {
360 item = path_list_insert(ce->name, unmerged);
361 item->util = xcalloc(1, sizeof(struct stage_data));
362 }
363 e = item->util;
364 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
365 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
366 }
367
368 return unmerged;
369 }
370
371 struct rename
372 {
373 struct diff_filepair *pair;
374 struct stage_data *src_entry;
375 struct stage_data *dst_entry;
376 unsigned processed:1;
377 };
378
379 /*
380 * Get information of all renames which occurred between 'o_tree' and
381 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
382 * 'b_tree') to be able to associate the correct cache entries with
383 * the rename information. 'tree' is always equal to either a_tree or b_tree.
384 */
385 static struct path_list *get_renames(struct tree *tree,
386 struct tree *o_tree,
387 struct tree *a_tree,
388 struct tree *b_tree,
389 struct path_list *entries)
390 {
391 int i;
392 struct path_list *renames;
393 struct diff_options opts;
394
395 renames = xcalloc(1, sizeof(struct path_list));
396 diff_setup(&opts);
397 opts.recursive = 1;
398 opts.detect_rename = DIFF_DETECT_RENAME;
399 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
400 if (diff_setup_done(&opts) < 0)
401 die("diff setup failed");
402 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
403 diffcore_std(&opts);
404 for (i = 0; i < diff_queued_diff.nr; ++i) {
405 struct path_list_item *item;
406 struct rename *re;
407 struct diff_filepair *pair = diff_queued_diff.queue[i];
408 if (pair->status != 'R') {
409 diff_free_filepair(pair);
410 continue;
411 }
412 re = xmalloc(sizeof(*re));
413 re->processed = 0;
414 re->pair = pair;
415 item = path_list_lookup(re->pair->one->path, entries);
416 if (!item)
417 re->src_entry = insert_stage_data(re->pair->one->path,
418 o_tree, a_tree, b_tree, entries);
419 else
420 re->src_entry = item->util;
421
422 item = path_list_lookup(re->pair->two->path, entries);
423 if (!item)
424 re->dst_entry = insert_stage_data(re->pair->two->path,
425 o_tree, a_tree, b_tree, entries);
426 else
427 re->dst_entry = item->util;
428 item = path_list_insert(pair->one->path, renames);
429 item->util = re;
430 }
431 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
432 diff_queued_diff.nr = 0;
433 diff_flush(&opts);
434 return renames;
435 }
436
437 static int update_stages(const char *path, struct diff_filespec *o,
438 struct diff_filespec *a, struct diff_filespec *b,
439 int clear)
440 {
441 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
442 if (clear)
443 if (remove_file_from_cache(path))
444 return -1;
445 if (o)
446 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
447 return -1;
448 if (a)
449 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
450 return -1;
451 if (b)
452 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
453 return -1;
454 return 0;
455 }
456
457 static int remove_path(const char *name)
458 {
459 int ret, len;
460 char *slash, *dirs;
461
462 ret = unlink(name);
463 if (ret)
464 return ret;
465 len = strlen(name);
466 dirs = xmalloc(len+1);
467 memcpy(dirs, name, len);
468 dirs[len] = '\0';
469 while ((slash = strrchr(name, '/'))) {
470 *slash = '\0';
471 len = slash - name;
472 if (rmdir(name) != 0)
473 break;
474 }
475 free(dirs);
476 return ret;
477 }
478
479 static int remove_file(int clean, const char *path, int no_wd)
480 {
481 int update_cache = index_only || clean;
482 int update_working_directory = !index_only && !no_wd;
483
484 if (update_cache) {
485 if (remove_file_from_cache(path))
486 return -1;
487 }
488 if (update_working_directory) {
489 unlink(path);
490 if (errno != ENOENT || errno != EISDIR)
491 return -1;
492 remove_path(path);
493 }
494 return 0;
495 }
496
497 static char *unique_path(const char *path, const char *branch)
498 {
499 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
500 int suffix = 0;
501 struct stat st;
502 char *p = newpath + strlen(path);
503 strcpy(newpath, path);
504 *(p++) = '~';
505 strcpy(p, branch);
506 for (; *p; ++p)
507 if ('/' == *p)
508 *p = '_';
509 while (path_list_has_path(&current_file_set, newpath) ||
510 path_list_has_path(&current_directory_set, newpath) ||
511 lstat(newpath, &st) == 0)
512 sprintf(p, "_%d", suffix++);
513
514 path_list_insert(newpath, &current_file_set);
515 return newpath;
516 }
517
518 static int mkdir_p(const char *path, unsigned long mode)
519 {
520 /* path points to cache entries, so xstrdup before messing with it */
521 char *buf = xstrdup(path);
522 int result = safe_create_leading_directories(buf);
523 free(buf);
524 return result;
525 }
526
527 static void flush_buffer(int fd, const char *buf, unsigned long size)
528 {
529 while (size > 0) {
530 long ret = write_in_full(fd, buf, size);
531 if (ret < 0) {
532 /* Ignore epipe */
533 if (errno == EPIPE)
534 break;
535 die("merge-recursive: %s", strerror(errno));
536 } else if (!ret) {
537 die("merge-recursive: disk full?");
538 }
539 size -= ret;
540 buf += ret;
541 }
542 }
543
544 static int make_room_for_path(const char *path)
545 {
546 int status;
547 const char *msg = "failed to create path '%s'%s";
548
549 status = mkdir_p(path, 0777);
550 if (status) {
551 if (status == -3) {
552 /* something else exists */
553 error(msg, path, ": perhaps a D/F conflict?");
554 return -1;
555 }
556 die(msg, path, "");
557 }
558
559 /* Successful unlink is good.. */
560 if (!unlink(path))
561 return 0;
562 /* .. and so is no existing file */
563 if (errno == ENOENT)
564 return 0;
565 /* .. but not some other error (who really cares what?) */
566 return error(msg, path, ": perhaps a D/F conflict?");
567 }
568
569 static void update_file_flags(const unsigned char *sha,
570 unsigned mode,
571 const char *path,
572 int update_cache,
573 int update_wd)
574 {
575 if (index_only)
576 update_wd = 0;
577
578 if (update_wd) {
579 enum object_type type;
580 void *buf;
581 unsigned long size;
582
583 buf = read_sha1_file(sha, &type, &size);
584 if (!buf)
585 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
586 if (type != OBJ_BLOB)
587 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
588
589 if (make_room_for_path(path) < 0) {
590 update_wd = 0;
591 goto update_index;
592 }
593 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
594 int fd;
595 if (mode & 0100)
596 mode = 0777;
597 else
598 mode = 0666;
599 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
600 if (fd < 0)
601 die("failed to open %s: %s", path, strerror(errno));
602 flush_buffer(fd, buf, size);
603 close(fd);
604 } else if (S_ISLNK(mode)) {
605 char *lnk = xmalloc(size + 1);
606 memcpy(lnk, buf, size);
607 lnk[size] = '\0';
608 mkdir_p(path, 0777);
609 unlink(path);
610 symlink(lnk, path);
611 free(lnk);
612 } else
613 die("do not know what to do with %06o %s '%s'",
614 mode, sha1_to_hex(sha), path);
615 }
616 update_index:
617 if (update_cache)
618 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
619 }
620
621 static void update_file(int clean,
622 const unsigned char *sha,
623 unsigned mode,
624 const char *path)
625 {
626 update_file_flags(sha, mode, path, index_only || clean, !index_only);
627 }
628
629 /* Low level file merging, update and removal */
630
631 struct merge_file_info
632 {
633 unsigned char sha[20];
634 unsigned mode;
635 unsigned clean:1,
636 merge:1;
637 };
638
639 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
640 {
641 unsigned long size;
642 enum object_type type;
643
644 if (!hashcmp(sha1, null_sha1)) {
645 mm->ptr = xstrdup("");
646 mm->size = 0;
647 return;
648 }
649
650 mm->ptr = read_sha1_file(sha1, &type, &size);
651 if (!mm->ptr || type != OBJ_BLOB)
652 die("unable to read blob object %s", sha1_to_hex(sha1));
653 mm->size = size;
654 }
655
656 /*
657 * Customizable low-level merge drivers support.
658 */
659
660 struct ll_merge_driver;
661 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
662 const char *path,
663 mmfile_t *orig,
664 mmfile_t *src1, const char *name1,
665 mmfile_t *src2, const char *name2,
666 mmbuffer_t *result);
667
668 struct ll_merge_driver {
669 const char *name;
670 const char *description;
671 ll_merge_fn fn;
672 const char *recursive;
673 struct ll_merge_driver *next;
674 char *cmdline;
675 };
676
677 /*
678 * Built-in low-levels
679 */
680 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
681 const char *path_unused,
682 mmfile_t *orig,
683 mmfile_t *src1, const char *name1,
684 mmfile_t *src2, const char *name2,
685 mmbuffer_t *result)
686 {
687 /*
688 * The tentative merge result is "ours" for the final round,
689 * or common ancestor for an internal merge. Still return
690 * "conflicted merge" status.
691 */
692 mmfile_t *stolen = index_only ? orig : src1;
693
694 result->ptr = stolen->ptr;
695 result->size = stolen->size;
696 stolen->ptr = NULL;
697 return 1;
698 }
699
700 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
701 const char *path_unused,
702 mmfile_t *orig,
703 mmfile_t *src1, const char *name1,
704 mmfile_t *src2, const char *name2,
705 mmbuffer_t *result)
706 {
707 xpparam_t xpp;
708
709 if (buffer_is_binary(orig->ptr, orig->size) ||
710 buffer_is_binary(src1->ptr, src1->size) ||
711 buffer_is_binary(src2->ptr, src2->size)) {
712 warning("Cannot merge binary files: %s vs. %s\n",
713 name1, name2);
714 return ll_binary_merge(drv_unused, path_unused,
715 orig, src1, name1,
716 src2, name2,
717 result);
718 }
719
720 memset(&xpp, 0, sizeof(xpp));
721 return xdl_merge(orig,
722 src1, name1,
723 src2, name2,
724 &xpp, XDL_MERGE_ZEALOUS,
725 result);
726 }
727
728 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
729 const char *path_unused,
730 mmfile_t *orig,
731 mmfile_t *src1, const char *name1,
732 mmfile_t *src2, const char *name2,
733 mmbuffer_t *result)
734 {
735 char *src, *dst;
736 long size;
737 const int marker_size = 7;
738
739 int status = ll_xdl_merge(drv_unused, path_unused,
740 orig, src1, NULL, src2, NULL, result);
741 if (status <= 0)
742 return status;
743 size = result->size;
744 src = dst = result->ptr;
745 while (size) {
746 char ch;
747 if ((marker_size < size) &&
748 (*src == '<' || *src == '=' || *src == '>')) {
749 int i;
750 ch = *src;
751 for (i = 0; i < marker_size; i++)
752 if (src[i] != ch)
753 goto not_a_marker;
754 if (src[marker_size] != '\n')
755 goto not_a_marker;
756 src += marker_size + 1;
757 size -= marker_size + 1;
758 continue;
759 }
760 not_a_marker:
761 do {
762 ch = *src++;
763 *dst++ = ch;
764 size--;
765 } while (ch != '\n' && size);
766 }
767 result->size = dst - result->ptr;
768 return 0;
769 }
770
771 #define LL_BINARY_MERGE 0
772 #define LL_TEXT_MERGE 1
773 #define LL_UNION_MERGE 2
774 static struct ll_merge_driver ll_merge_drv[] = {
775 { "binary", "built-in binary merge", ll_binary_merge },
776 { "text", "built-in 3-way text merge", ll_xdl_merge },
777 { "union", "built-in union merge", ll_union_merge },
778 };
779
780 static void create_temp(mmfile_t *src, char *path)
781 {
782 int fd;
783
784 strcpy(path, ".merge_file_XXXXXX");
785 fd = xmkstemp(path);
786 if (write_in_full(fd, src->ptr, src->size) != src->size)
787 die("unable to write temp-file");
788 close(fd);
789 }
790
791 /*
792 * User defined low-level merge driver support.
793 */
794 static int ll_ext_merge(const struct ll_merge_driver *fn,
795 const char *path,
796 mmfile_t *orig,
797 mmfile_t *src1, const char *name1,
798 mmfile_t *src2, const char *name2,
799 mmbuffer_t *result)
800 {
801 char temp[3][50];
802 char cmdbuf[2048];
803 struct interp table[] = {
804 { "%O" },
805 { "%A" },
806 { "%B" },
807 };
808 struct child_process child;
809 const char *args[20];
810 int status, fd, i;
811 struct stat st;
812
813 if (fn->cmdline == NULL)
814 die("custom merge driver %s lacks command line.", fn->name);
815
816 result->ptr = NULL;
817 result->size = 0;
818 create_temp(orig, temp[0]);
819 create_temp(src1, temp[1]);
820 create_temp(src2, temp[2]);
821
822 interp_set_entry(table, 0, temp[0]);
823 interp_set_entry(table, 1, temp[1]);
824 interp_set_entry(table, 2, temp[2]);
825
826 output(1, "merging %s using %s", path,
827 fn->description ? fn->description : fn->name);
828
829 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
830
831 memset(&child, 0, sizeof(child));
832 child.argv = args;
833 args[0] = "sh";
834 args[1] = "-c";
835 args[2] = cmdbuf;
836 args[3] = NULL;
837
838 status = run_command(&child);
839 if (status < -ERR_RUN_COMMAND_FORK)
840 ; /* failure in run-command */
841 else
842 status = -status;
843 fd = open(temp[1], O_RDONLY);
844 if (fd < 0)
845 goto bad;
846 if (fstat(fd, &st))
847 goto close_bad;
848 result->size = st.st_size;
849 result->ptr = xmalloc(result->size + 1);
850 if (read_in_full(fd, result->ptr, result->size) != result->size) {
851 free(result->ptr);
852 result->ptr = NULL;
853 result->size = 0;
854 }
855 close_bad:
856 close(fd);
857 bad:
858 for (i = 0; i < 3; i++)
859 unlink(temp[i]);
860 return status;
861 }
862
863 /*
864 * merge.default and merge.driver configuration items
865 */
866 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
867 static const char *default_ll_merge;
868
869 static int read_merge_config(const char *var, const char *value)
870 {
871 struct ll_merge_driver *fn;
872 const char *ep, *name;
873 int namelen;
874
875 if (!strcmp(var, "merge.default")) {
876 if (value)
877 default_ll_merge = strdup(value);
878 return 0;
879 }
880
881 /*
882 * We are not interested in anything but "merge.<name>.variable";
883 * especially, we do not want to look at variables such as
884 * "merge.summary", "merge.tool", and "merge.verbosity".
885 */
886 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
887 return 0;
888
889 /*
890 * Find existing one as we might be processing merge.<name>.var2
891 * after seeing merge.<name>.var1.
892 */
893 name = var + 6;
894 namelen = ep - name;
895 for (fn = ll_user_merge; fn; fn = fn->next)
896 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
897 break;
898 if (!fn) {
899 char *namebuf;
900 fn = xcalloc(1, sizeof(struct ll_merge_driver));
901 namebuf = xmalloc(namelen + 1);
902 memcpy(namebuf, name, namelen);
903 namebuf[namelen] = 0;
904 fn->name = namebuf;
905 fn->fn = ll_ext_merge;
906 fn->next = NULL;
907 *ll_user_merge_tail = fn;
908 ll_user_merge_tail = &(fn->next);
909 }
910
911 ep++;
912
913 if (!strcmp("name", ep)) {
914 if (!value)
915 return error("%s: lacks value", var);
916 fn->description = strdup(value);
917 return 0;
918 }
919
920 if (!strcmp("driver", ep)) {
921 if (!value)
922 return error("%s: lacks value", var);
923 /*
924 * merge.<name>.driver specifies the command line:
925 *
926 * command-line
927 *
928 * The command-line will be interpolated with the following
929 * tokens and is given to the shell:
930 *
931 * %O - temporary file name for the merge base.
932 * %A - temporary file name for our version.
933 * %B - temporary file name for the other branches' version.
934 *
935 * The external merge driver should write the results in the
936 * file named by %A, and signal that it has done with zero exit
937 * status.
938 */
939 fn->cmdline = strdup(value);
940 return 0;
941 }
942
943 if (!strcmp("recursive", ep)) {
944 if (!value)
945 return error("%s: lacks value", var);
946 fn->recursive = strdup(value);
947 return 0;
948 }
949
950 return 0;
951 }
952
953 static void initialize_ll_merge(void)
954 {
955 if (ll_user_merge_tail)
956 return;
957 ll_user_merge_tail = &ll_user_merge;
958 git_config(read_merge_config);
959 }
960
961 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
962 {
963 struct ll_merge_driver *fn;
964 const char *name;
965 int i;
966
967 initialize_ll_merge();
968
969 if (ATTR_TRUE(merge_attr))
970 return &ll_merge_drv[LL_TEXT_MERGE];
971 else if (ATTR_FALSE(merge_attr))
972 return &ll_merge_drv[LL_BINARY_MERGE];
973 else if (ATTR_UNSET(merge_attr)) {
974 if (!default_ll_merge)
975 return &ll_merge_drv[LL_TEXT_MERGE];
976 else
977 name = default_ll_merge;
978 }
979 else
980 name = merge_attr;
981
982 for (fn = ll_user_merge; fn; fn = fn->next)
983 if (!strcmp(fn->name, name))
984 return fn;
985
986 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
987 if (!strcmp(ll_merge_drv[i].name, name))
988 return &ll_merge_drv[i];
989
990 /* default to the 3-way */
991 return &ll_merge_drv[LL_TEXT_MERGE];
992 }
993
994 static const char *git_path_check_merge(const char *path)
995 {
996 static struct git_attr_check attr_merge_check;
997
998 if (!attr_merge_check.attr)
999 attr_merge_check.attr = git_attr("merge", 5);
1000
1001 if (git_checkattr(path, 1, &attr_merge_check))
1002 return NULL;
1003 return attr_merge_check.value;
1004 }
1005
1006 static int ll_merge(mmbuffer_t *result_buf,
1007 struct diff_filespec *o,
1008 struct diff_filespec *a,
1009 struct diff_filespec *b,
1010 const char *branch1,
1011 const char *branch2)
1012 {
1013 mmfile_t orig, src1, src2;
1014 char *name1, *name2;
1015 int merge_status;
1016 const char *ll_driver_name;
1017 const struct ll_merge_driver *driver;
1018
1019 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1020 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1021
1022 fill_mm(o->sha1, &orig);
1023 fill_mm(a->sha1, &src1);
1024 fill_mm(b->sha1, &src2);
1025
1026 ll_driver_name = git_path_check_merge(a->path);
1027 driver = find_ll_merge_driver(ll_driver_name);
1028
1029 if (index_only && driver->recursive)
1030 driver = find_ll_merge_driver(driver->recursive);
1031 merge_status = driver->fn(driver, a->path,
1032 &orig, &src1, name1, &src2, name2,
1033 result_buf);
1034
1035 free(name1);
1036 free(name2);
1037 free(orig.ptr);
1038 free(src1.ptr);
1039 free(src2.ptr);
1040 return merge_status;
1041 }
1042
1043 static struct merge_file_info merge_file(struct diff_filespec *o,
1044 struct diff_filespec *a, struct diff_filespec *b,
1045 const char *branch1, const char *branch2)
1046 {
1047 struct merge_file_info result;
1048 result.merge = 0;
1049 result.clean = 1;
1050
1051 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1052 result.clean = 0;
1053 if (S_ISREG(a->mode)) {
1054 result.mode = a->mode;
1055 hashcpy(result.sha, a->sha1);
1056 } else {
1057 result.mode = b->mode;
1058 hashcpy(result.sha, b->sha1);
1059 }
1060 } else {
1061 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1062 result.merge = 1;
1063
1064 result.mode = a->mode == o->mode ? b->mode: a->mode;
1065
1066 if (sha_eq(a->sha1, o->sha1))
1067 hashcpy(result.sha, b->sha1);
1068 else if (sha_eq(b->sha1, o->sha1))
1069 hashcpy(result.sha, a->sha1);
1070 else if (S_ISREG(a->mode)) {
1071 mmbuffer_t result_buf;
1072 int merge_status;
1073
1074 merge_status = ll_merge(&result_buf, o, a, b,
1075 branch1, branch2);
1076
1077 if ((merge_status < 0) || !result_buf.ptr)
1078 die("Failed to execute internal merge");
1079
1080 if (write_sha1_file(result_buf.ptr, result_buf.size,
1081 blob_type, result.sha))
1082 die("Unable to add %s to database",
1083 a->path);
1084
1085 free(result_buf.ptr);
1086 result.clean = (merge_status == 0);
1087 } else {
1088 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1089 die("cannot merge modes?");
1090
1091 hashcpy(result.sha, a->sha1);
1092
1093 if (!sha_eq(a->sha1, b->sha1))
1094 result.clean = 0;
1095 }
1096 }
1097
1098 return result;
1099 }
1100
1101 static void conflict_rename_rename(struct rename *ren1,
1102 const char *branch1,
1103 struct rename *ren2,
1104 const char *branch2)
1105 {
1106 char *del[2];
1107 int delp = 0;
1108 const char *ren1_dst = ren1->pair->two->path;
1109 const char *ren2_dst = ren2->pair->two->path;
1110 const char *dst_name1 = ren1_dst;
1111 const char *dst_name2 = ren2_dst;
1112 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1113 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1114 output(1, "%s is a directory in %s added as %s instead",
1115 ren1_dst, branch2, dst_name1);
1116 remove_file(0, ren1_dst, 0);
1117 }
1118 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1119 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1120 output(1, "%s is a directory in %s added as %s instead",
1121 ren2_dst, branch1, dst_name2);
1122 remove_file(0, ren2_dst, 0);
1123 }
1124 if (index_only) {
1125 remove_file_from_cache(dst_name1);
1126 remove_file_from_cache(dst_name2);
1127 /*
1128 * Uncomment to leave the conflicting names in the resulting tree
1129 *
1130 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1131 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1132 */
1133 } else {
1134 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1135 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1136 }
1137 while (delp--)
1138 free(del[delp]);
1139 }
1140
1141 static void conflict_rename_dir(struct rename *ren1,
1142 const char *branch1)
1143 {
1144 char *new_path = unique_path(ren1->pair->two->path, branch1);
1145 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1146 remove_file(0, ren1->pair->two->path, 0);
1147 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1148 free(new_path);
1149 }
1150
1151 static void conflict_rename_rename_2(struct rename *ren1,
1152 const char *branch1,
1153 struct rename *ren2,
1154 const char *branch2)
1155 {
1156 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1157 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1158 output(1, "Renamed %s to %s and %s to %s instead",
1159 ren1->pair->one->path, new_path1,
1160 ren2->pair->one->path, new_path2);
1161 remove_file(0, ren1->pair->two->path, 0);
1162 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1163 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1164 free(new_path2);
1165 free(new_path1);
1166 }
1167
1168 static int process_renames(struct path_list *a_renames,
1169 struct path_list *b_renames,
1170 const char *a_branch,
1171 const char *b_branch)
1172 {
1173 int clean_merge = 1, i, j;
1174 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1175 const struct rename *sre;
1176
1177 for (i = 0; i < a_renames->nr; i++) {
1178 sre = a_renames->items[i].util;
1179 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1180 = sre->dst_entry;
1181 }
1182 for (i = 0; i < b_renames->nr; i++) {
1183 sre = b_renames->items[i].util;
1184 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1185 = sre->dst_entry;
1186 }
1187
1188 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1189 int compare;
1190 char *src;
1191 struct path_list *renames1, *renames2, *renames2Dst;
1192 struct rename *ren1 = NULL, *ren2 = NULL;
1193 const char *branch1, *branch2;
1194 const char *ren1_src, *ren1_dst;
1195
1196 if (i >= a_renames->nr) {
1197 compare = 1;
1198 ren2 = b_renames->items[j++].util;
1199 } else if (j >= b_renames->nr) {
1200 compare = -1;
1201 ren1 = a_renames->items[i++].util;
1202 } else {
1203 compare = strcmp(a_renames->items[i].path,
1204 b_renames->items[j].path);
1205 if (compare <= 0)
1206 ren1 = a_renames->items[i++].util;
1207 if (compare >= 0)
1208 ren2 = b_renames->items[j++].util;
1209 }
1210
1211 /* TODO: refactor, so that 1/2 are not needed */
1212 if (ren1) {
1213 renames1 = a_renames;
1214 renames2 = b_renames;
1215 renames2Dst = &b_by_dst;
1216 branch1 = a_branch;
1217 branch2 = b_branch;
1218 } else {
1219 struct rename *tmp;
1220 renames1 = b_renames;
1221 renames2 = a_renames;
1222 renames2Dst = &a_by_dst;
1223 branch1 = b_branch;
1224 branch2 = a_branch;
1225 tmp = ren2;
1226 ren2 = ren1;
1227 ren1 = tmp;
1228 }
1229 src = ren1->pair->one->path;
1230
1231 ren1->dst_entry->processed = 1;
1232 ren1->src_entry->processed = 1;
1233
1234 if (ren1->processed)
1235 continue;
1236 ren1->processed = 1;
1237
1238 ren1_src = ren1->pair->one->path;
1239 ren1_dst = ren1->pair->two->path;
1240
1241 if (ren2) {
1242 const char *ren2_src = ren2->pair->one->path;
1243 const char *ren2_dst = ren2->pair->two->path;
1244 /* Renamed in 1 and renamed in 2 */
1245 if (strcmp(ren1_src, ren2_src) != 0)
1246 die("ren1.src != ren2.src");
1247 ren2->dst_entry->processed = 1;
1248 ren2->processed = 1;
1249 if (strcmp(ren1_dst, ren2_dst) != 0) {
1250 clean_merge = 0;
1251 output(1, "CONFLICT (rename/rename): "
1252 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1253 "rename \"%s\"->\"%s\" in \"%s\"%s",
1254 src, ren1_dst, branch1,
1255 src, ren2_dst, branch2,
1256 index_only ? " (left unresolved)": "");
1257 if (index_only) {
1258 remove_file_from_cache(src);
1259 update_file(0, ren1->pair->one->sha1,
1260 ren1->pair->one->mode, src);
1261 }
1262 conflict_rename_rename(ren1, branch1, ren2, branch2);
1263 } else {
1264 struct merge_file_info mfi;
1265 remove_file(1, ren1_src, 1);
1266 mfi = merge_file(ren1->pair->one,
1267 ren1->pair->two,
1268 ren2->pair->two,
1269 branch1,
1270 branch2);
1271 if (mfi.merge || !mfi.clean)
1272 output(1, "Renamed %s->%s", src, ren1_dst);
1273
1274 if (mfi.merge)
1275 output(2, "Auto-merged %s", ren1_dst);
1276
1277 if (!mfi.clean) {
1278 output(1, "CONFLICT (content): merge conflict in %s",
1279 ren1_dst);
1280 clean_merge = 0;
1281
1282 if (!index_only)
1283 update_stages(ren1_dst,
1284 ren1->pair->one,
1285 ren1->pair->two,
1286 ren2->pair->two,
1287 1 /* clear */);
1288 }
1289 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1290 }
1291 } else {
1292 /* Renamed in 1, maybe changed in 2 */
1293 struct path_list_item *item;
1294 /* we only use sha1 and mode of these */
1295 struct diff_filespec src_other, dst_other;
1296 int try_merge, stage = a_renames == renames1 ? 3: 2;
1297
1298 remove_file(1, ren1_src, index_only || stage == 3);
1299
1300 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1301 src_other.mode = ren1->src_entry->stages[stage].mode;
1302 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1303 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1304
1305 try_merge = 0;
1306
1307 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1308 clean_merge = 0;
1309 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1310 " directory %s added in %s",
1311 ren1_src, ren1_dst, branch1,
1312 ren1_dst, branch2);
1313 conflict_rename_dir(ren1, branch1);
1314 } else if (sha_eq(src_other.sha1, null_sha1)) {
1315 clean_merge = 0;
1316 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1317 "and deleted in %s",
1318 ren1_src, ren1_dst, branch1,
1319 branch2);
1320 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1321 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1322 const char *new_path;
1323 clean_merge = 0;
1324 try_merge = 1;
1325 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1326 "%s added in %s",
1327 ren1_src, ren1_dst, branch1,
1328 ren1_dst, branch2);
1329 new_path = unique_path(ren1_dst, branch2);
1330 output(1, "Added as %s instead", new_path);
1331 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1332 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1333 ren2 = item->util;
1334 clean_merge = 0;
1335 ren2->processed = 1;
1336 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1337 "Renamed %s->%s in %s",
1338 ren1_src, ren1_dst, branch1,
1339 ren2->pair->one->path, ren2->pair->two->path, branch2);
1340 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1341 } else
1342 try_merge = 1;
1343
1344 if (try_merge) {
1345 struct diff_filespec *o, *a, *b;
1346 struct merge_file_info mfi;
1347 src_other.path = (char *)ren1_src;
1348
1349 o = ren1->pair->one;
1350 if (a_renames == renames1) {
1351 a = ren1->pair->two;
1352 b = &src_other;
1353 } else {
1354 b = ren1->pair->two;
1355 a = &src_other;
1356 }
1357 mfi = merge_file(o, a, b,
1358 a_branch, b_branch);
1359
1360 if (mfi.clean &&
1361 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1362 mfi.mode == ren1->pair->two->mode)
1363 /*
1364 * This messaged is part of
1365 * t6022 test. If you change
1366 * it update the test too.
1367 */
1368 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1369 else {
1370 if (mfi.merge || !mfi.clean)
1371 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1372 if (mfi.merge)
1373 output(2, "Auto-merged %s", ren1_dst);
1374 if (!mfi.clean) {
1375 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1376 ren1_dst);
1377 clean_merge = 0;
1378
1379 if (!index_only)
1380 update_stages(ren1_dst,
1381 o, a, b, 1);
1382 }
1383 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1384 }
1385 }
1386 }
1387 }
1388 path_list_clear(&a_by_dst, 0);
1389 path_list_clear(&b_by_dst, 0);
1390
1391 return clean_merge;
1392 }
1393
1394 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1395 {
1396 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1397 }
1398
1399 /* Per entry merge function */
1400 static int process_entry(const char *path, struct stage_data *entry,
1401 const char *branch1,
1402 const char *branch2)
1403 {
1404 /*
1405 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1406 print_index_entry("\tpath: ", entry);
1407 */
1408 int clean_merge = 1;
1409 unsigned o_mode = entry->stages[1].mode;
1410 unsigned a_mode = entry->stages[2].mode;
1411 unsigned b_mode = entry->stages[3].mode;
1412 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1413 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1414 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1415
1416 if (o_sha && (!a_sha || !b_sha)) {
1417 /* Case A: Deleted in one */
1418 if ((!a_sha && !b_sha) ||
1419 (sha_eq(a_sha, o_sha) && !b_sha) ||
1420 (!a_sha && sha_eq(b_sha, o_sha))) {
1421 /* Deleted in both or deleted in one and
1422 * unchanged in the other */
1423 if (a_sha)
1424 output(2, "Removed %s", path);
1425 /* do not touch working file if it did not exist */
1426 remove_file(1, path, !a_sha);
1427 } else {
1428 /* Deleted in one and changed in the other */
1429 clean_merge = 0;
1430 if (!a_sha) {
1431 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1432 "and modified in %s. Version %s of %s left in tree.",
1433 path, branch1,
1434 branch2, branch2, path);
1435 update_file(0, b_sha, b_mode, path);
1436 } else {
1437 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1438 "and modified in %s. Version %s of %s left in tree.",
1439 path, branch2,
1440 branch1, branch1, path);
1441 update_file(0, a_sha, a_mode, path);
1442 }
1443 }
1444
1445 } else if ((!o_sha && a_sha && !b_sha) ||
1446 (!o_sha && !a_sha && b_sha)) {
1447 /* Case B: Added in one. */
1448 const char *add_branch;
1449 const char *other_branch;
1450 unsigned mode;
1451 const unsigned char *sha;
1452 const char *conf;
1453
1454 if (a_sha) {
1455 add_branch = branch1;
1456 other_branch = branch2;
1457 mode = a_mode;
1458 sha = a_sha;
1459 conf = "file/directory";
1460 } else {
1461 add_branch = branch2;
1462 other_branch = branch1;
1463 mode = b_mode;
1464 sha = b_sha;
1465 conf = "directory/file";
1466 }
1467 if (path_list_has_path(&current_directory_set, path)) {
1468 const char *new_path = unique_path(path, add_branch);
1469 clean_merge = 0;
1470 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1471 "Added %s as %s",
1472 conf, path, other_branch, path, new_path);
1473 remove_file(0, path, 0);
1474 update_file(0, sha, mode, new_path);
1475 } else {
1476 output(2, "Added %s", path);
1477 update_file(1, sha, mode, path);
1478 }
1479 } else if (a_sha && b_sha) {
1480 /* Case C: Added in both (check for same permissions) and */
1481 /* case D: Modified in both, but differently. */
1482 const char *reason = "content";
1483 struct merge_file_info mfi;
1484 struct diff_filespec o, a, b;
1485
1486 if (!o_sha) {
1487 reason = "add/add";
1488 o_sha = (unsigned char *)null_sha1;
1489 }
1490 output(2, "Auto-merged %s", path);
1491 o.path = a.path = b.path = (char *)path;
1492 hashcpy(o.sha1, o_sha);
1493 o.mode = o_mode;
1494 hashcpy(a.sha1, a_sha);
1495 a.mode = a_mode;
1496 hashcpy(b.sha1, b_sha);
1497 b.mode = b_mode;
1498
1499 mfi = merge_file(&o, &a, &b,
1500 branch1, branch2);
1501
1502 if (mfi.clean)
1503 update_file(1, mfi.sha, mfi.mode, path);
1504 else {
1505 clean_merge = 0;
1506 output(1, "CONFLICT (%s): Merge conflict in %s",
1507 reason, path);
1508
1509 if (index_only)
1510 update_file(0, mfi.sha, mfi.mode, path);
1511 else
1512 update_file_flags(mfi.sha, mfi.mode, path,
1513 0 /* update_cache */, 1 /* update_working_directory */);
1514 }
1515 } else if (!o_sha && !a_sha && !b_sha) {
1516 /*
1517 * this entry was deleted altogether. a_mode == 0 means
1518 * we had that path and want to actively remove it.
1519 */
1520 remove_file(1, path, !a_mode);
1521 } else
1522 die("Fatal merge failure, shouldn't happen.");
1523
1524 return clean_merge;
1525 }
1526
1527 static int merge_trees(struct tree *head,
1528 struct tree *merge,
1529 struct tree *common,
1530 const char *branch1,
1531 const char *branch2,
1532 struct tree **result)
1533 {
1534 int code, clean;
1535
1536 if (subtree_merge) {
1537 merge = shift_tree_object(head, merge);
1538 common = shift_tree_object(head, common);
1539 }
1540
1541 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1542 output(0, "Already uptodate!");
1543 *result = head;
1544 return 1;
1545 }
1546
1547 code = git_merge_trees(index_only, common, head, merge);
1548
1549 if (code != 0)
1550 die("merging of trees %s and %s failed",
1551 sha1_to_hex(head->object.sha1),
1552 sha1_to_hex(merge->object.sha1));
1553
1554 if (unmerged_index()) {
1555 struct path_list *entries, *re_head, *re_merge;
1556 int i;
1557 path_list_clear(&current_file_set, 1);
1558 path_list_clear(&current_directory_set, 1);
1559 get_files_dirs(head);
1560 get_files_dirs(merge);
1561
1562 entries = get_unmerged();
1563 re_head = get_renames(head, common, head, merge, entries);
1564 re_merge = get_renames(merge, common, head, merge, entries);
1565 clean = process_renames(re_head, re_merge,
1566 branch1, branch2);
1567 for (i = 0; i < entries->nr; i++) {
1568 const char *path = entries->items[i].path;
1569 struct stage_data *e = entries->items[i].util;
1570 if (!e->processed
1571 && !process_entry(path, e, branch1, branch2))
1572 clean = 0;
1573 }
1574
1575 path_list_clear(re_merge, 0);
1576 path_list_clear(re_head, 0);
1577 path_list_clear(entries, 1);
1578
1579 }
1580 else
1581 clean = 1;
1582
1583 if (index_only)
1584 *result = git_write_tree();
1585
1586 return clean;
1587 }
1588
1589 static struct commit_list *reverse_commit_list(struct commit_list *list)
1590 {
1591 struct commit_list *next = NULL, *current, *backup;
1592 for (current = list; current; current = backup) {
1593 backup = current->next;
1594 current->next = next;
1595 next = current;
1596 }
1597 return next;
1598 }
1599
1600 /*
1601 * Merge the commits h1 and h2, return the resulting virtual
1602 * commit object and a flag indicating the cleanness of the merge.
1603 */
1604 static int merge(struct commit *h1,
1605 struct commit *h2,
1606 const char *branch1,
1607 const char *branch2,
1608 struct commit_list *ca,
1609 struct commit **result)
1610 {
1611 struct commit_list *iter;
1612 struct commit *merged_common_ancestors;
1613 struct tree *mrtree;
1614 int clean;
1615
1616 if (show(4)) {
1617 output(4, "Merging:");
1618 output_commit_title(h1);
1619 output_commit_title(h2);
1620 }
1621
1622 if (!ca) {
1623 ca = get_merge_bases(h1, h2, 1);
1624 ca = reverse_commit_list(ca);
1625 }
1626
1627 if (show(5)) {
1628 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1629 for (iter = ca; iter; iter = iter->next)
1630 output_commit_title(iter->item);
1631 }
1632
1633 merged_common_ancestors = pop_commit(&ca);
1634 if (merged_common_ancestors == NULL) {
1635 /* if there is no common ancestor, make an empty tree */
1636 struct tree *tree = xcalloc(1, sizeof(struct tree));
1637
1638 tree->object.parsed = 1;
1639 tree->object.type = OBJ_TREE;
1640 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1641 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1642 }
1643
1644 for (iter = ca; iter; iter = iter->next) {
1645 call_depth++;
1646 /*
1647 * When the merge fails, the result contains files
1648 * with conflict markers. The cleanness flag is
1649 * ignored, it was never actually used, as result of
1650 * merge_trees has always overwritten it: the committed
1651 * "conflicts" were already resolved.
1652 */
1653 discard_cache();
1654 merge(merged_common_ancestors, iter->item,
1655 "Temporary merge branch 1",
1656 "Temporary merge branch 2",
1657 NULL,
1658 &merged_common_ancestors);
1659 call_depth--;
1660
1661 if (!merged_common_ancestors)
1662 die("merge returned no commit");
1663 }
1664
1665 discard_cache();
1666 if (!call_depth) {
1667 read_cache();
1668 index_only = 0;
1669 } else
1670 index_only = 1;
1671
1672 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1673 branch1, branch2, &mrtree);
1674
1675 if (index_only) {
1676 *result = make_virtual_commit(mrtree, "merged tree");
1677 commit_list_insert(h1, &(*result)->parents);
1678 commit_list_insert(h2, &(*result)->parents->next);
1679 }
1680 flush_output();
1681 return clean;
1682 }
1683
1684 static const char *better_branch_name(const char *branch)
1685 {
1686 static char githead_env[8 + 40 + 1];
1687 char *name;
1688
1689 if (strlen(branch) != 40)
1690 return branch;
1691 sprintf(githead_env, "GITHEAD_%s", branch);
1692 name = getenv(githead_env);
1693 return name ? name : branch;
1694 }
1695
1696 static struct commit *get_ref(const char *ref)
1697 {
1698 unsigned char sha1[20];
1699 struct object *object;
1700
1701 if (get_sha1(ref, sha1))
1702 die("Could not resolve ref '%s'", ref);
1703 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1704 if (object->type == OBJ_TREE)
1705 return make_virtual_commit((struct tree*)object,
1706 better_branch_name(ref));
1707 if (object->type != OBJ_COMMIT)
1708 return NULL;
1709 if (parse_commit((struct commit *)object))
1710 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1711 return (struct commit *)object;
1712 }
1713
1714 static int merge_config(const char *var, const char *value)
1715 {
1716 if (!strcasecmp(var, "merge.verbosity")) {
1717 verbosity = git_config_int(var, value);
1718 return 0;
1719 }
1720 return git_default_config(var, value);
1721 }
1722
1723 int main(int argc, char *argv[])
1724 {
1725 static const char *bases[20];
1726 static unsigned bases_count = 0;
1727 int i, clean;
1728 const char *branch1, *branch2;
1729 struct commit *result, *h1, *h2;
1730 struct commit_list *ca = NULL;
1731 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1732 int index_fd;
1733
1734 if (argv[0]) {
1735 int namelen = strlen(argv[0]);
1736 if (8 < namelen &&
1737 !strcmp(argv[0] + namelen - 8, "-subtree"))
1738 subtree_merge = 1;
1739 }
1740
1741 git_config(merge_config);
1742 if (getenv("GIT_MERGE_VERBOSITY"))
1743 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1744
1745 if (argc < 4)
1746 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1747
1748 for (i = 1; i < argc; ++i) {
1749 if (!strcmp(argv[i], "--"))
1750 break;
1751 if (bases_count < sizeof(bases)/sizeof(*bases))
1752 bases[bases_count++] = argv[i];
1753 }
1754 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1755 die("Not handling anything other than two heads merge.");
1756 if (verbosity >= 5)
1757 buffer_output = 0;
1758
1759 branch1 = argv[++i];
1760 branch2 = argv[++i];
1761
1762 h1 = get_ref(branch1);
1763 h2 = get_ref(branch2);
1764
1765 branch1 = better_branch_name(branch1);
1766 branch2 = better_branch_name(branch2);
1767
1768 if (show(3))
1769 printf("Merging %s with %s\n", branch1, branch2);
1770
1771 index_fd = hold_locked_index(lock, 1);
1772
1773 for (i = 0; i < bases_count; i++) {
1774 struct commit *ancestor = get_ref(bases[i]);
1775 ca = commit_list_insert(ancestor, &ca);
1776 }
1777 clean = merge(h1, h2, branch1, branch2, ca, &result);
1778
1779 if (active_cache_changed &&
1780 (write_cache(index_fd, active_cache, active_nr) ||
1781 close(index_fd) || commit_locked_index(lock)))
1782 die ("unable to write %s", get_index_file());
1783
1784 return clean ? 0: 1;
1785 }
Jonathan Nieder’s miscellaneous git branches