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Whip post 1.5.3.3 maintenance series into shape.
[git/jrn.git] / merge-recursive.c
blob19d5f3b2872ec7039508c9b12a89f3013d58c68d
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 int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
175 const char *path, int stage, int refresh, int options)
176 {
177 struct cache_entry *ce;
178 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
179 if (!ce)
180 return error("addinfo_cache failed for path '%s'", path);
181 return add_cache_entry(ce, options);
182 }
183
184 /*
185 * This is a global variable which is used in a number of places but
186 * only written to in the 'merge' function.
187 *
188 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
189 * don't update the working directory.
190 * 0 => Leave unmerged entries in the cache and update
191 * the working directory.
192 */
193 static int index_only = 0;
194
195 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
196 {
197 parse_tree(tree);
198 init_tree_desc(desc, tree->buffer, tree->size);
199 }
200
201 static int git_merge_trees(int index_only,
202 struct tree *common,
203 struct tree *head,
204 struct tree *merge)
205 {
206 int rc;
207 struct tree_desc t[3];
208 struct unpack_trees_options opts;
209
210 memset(&opts, 0, sizeof(opts));
211 if (index_only)
212 opts.index_only = 1;
213 else
214 opts.update = 1;
215 opts.merge = 1;
216 opts.head_idx = 2;
217 opts.fn = threeway_merge;
218
219 init_tree_desc_from_tree(t+0, common);
220 init_tree_desc_from_tree(t+1, head);
221 init_tree_desc_from_tree(t+2, merge);
222
223 rc = unpack_trees(3, t, &opts);
224 cache_tree_free(&active_cache_tree);
225 return rc;
226 }
227
228 static int unmerged_index(void)
229 {
230 int i;
231 for (i = 0; i < active_nr; i++) {
232 struct cache_entry *ce = active_cache[i];
233 if (ce_stage(ce))
234 return 1;
235 }
236 return 0;
237 }
238
239 static struct tree *git_write_tree(void)
240 {
241 struct tree *result = NULL;
242
243 if (unmerged_index()) {
244 int i;
245 output(0, "There are unmerged index entries:");
246 for (i = 0; i < active_nr; i++) {
247 struct cache_entry *ce = active_cache[i];
248 if (ce_stage(ce))
249 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
250 }
251 return NULL;
252 }
253
254 if (!active_cache_tree)
255 active_cache_tree = cache_tree();
256
257 if (!cache_tree_fully_valid(active_cache_tree) &&
258 cache_tree_update(active_cache_tree,
259 active_cache, active_nr, 0, 0) < 0)
260 die("error building trees");
261
262 result = lookup_tree(active_cache_tree->sha1);
263
264 return result;
265 }
266
267 static int save_files_dirs(const unsigned char *sha1,
268 const char *base, int baselen, const char *path,
269 unsigned int mode, int stage)
270 {
271 int len = strlen(path);
272 char *newpath = xmalloc(baselen + len + 1);
273 memcpy(newpath, base, baselen);
274 memcpy(newpath + baselen, path, len);
275 newpath[baselen + len] = '\0';
276
277 if (S_ISDIR(mode))
278 path_list_insert(newpath, &current_directory_set);
279 else
280 path_list_insert(newpath, &current_file_set);
281 free(newpath);
282
283 return READ_TREE_RECURSIVE;
284 }
285
286 static int get_files_dirs(struct tree *tree)
287 {
288 int n;
289 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
290 return 0;
291 n = current_file_set.nr + current_directory_set.nr;
292 return n;
293 }
294
295 /*
296 * Returns a index_entry instance which doesn't have to correspond to
297 * a real cache entry in Git's index.
298 */
299 static struct stage_data *insert_stage_data(const char *path,
300 struct tree *o, struct tree *a, struct tree *b,
301 struct path_list *entries)
302 {
303 struct path_list_item *item;
304 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
305 get_tree_entry(o->object.sha1, path,
306 e->stages[1].sha, &e->stages[1].mode);
307 get_tree_entry(a->object.sha1, path,
308 e->stages[2].sha, &e->stages[2].mode);
309 get_tree_entry(b->object.sha1, path,
310 e->stages[3].sha, &e->stages[3].mode);
311 item = path_list_insert(path, entries);
312 item->util = e;
313 return e;
314 }
315
316 /*
317 * Create a dictionary mapping file names to stage_data objects. The
318 * dictionary contains one entry for every path with a non-zero stage entry.
319 */
320 static struct path_list *get_unmerged(void)
321 {
322 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
323 int i;
324
325 unmerged->strdup_paths = 1;
326
327 for (i = 0; i < active_nr; i++) {
328 struct path_list_item *item;
329 struct stage_data *e;
330 struct cache_entry *ce = active_cache[i];
331 if (!ce_stage(ce))
332 continue;
333
334 item = path_list_lookup(ce->name, unmerged);
335 if (!item) {
336 item = path_list_insert(ce->name, unmerged);
337 item->util = xcalloc(1, sizeof(struct stage_data));
338 }
339 e = item->util;
340 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
341 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
342 }
343
344 return unmerged;
345 }
346
347 struct rename
348 {
349 struct diff_filepair *pair;
350 struct stage_data *src_entry;
351 struct stage_data *dst_entry;
352 unsigned processed:1;
353 };
354
355 /*
356 * Get information of all renames which occurred between 'o_tree' and
357 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
358 * 'b_tree') to be able to associate the correct cache entries with
359 * the rename information. 'tree' is always equal to either a_tree or b_tree.
360 */
361 static struct path_list *get_renames(struct tree *tree,
362 struct tree *o_tree,
363 struct tree *a_tree,
364 struct tree *b_tree,
365 struct path_list *entries)
366 {
367 int i;
368 struct path_list *renames;
369 struct diff_options opts;
370
371 renames = xcalloc(1, sizeof(struct path_list));
372 diff_setup(&opts);
373 opts.recursive = 1;
374 opts.detect_rename = DIFF_DETECT_RENAME;
375 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
376 if (diff_setup_done(&opts) < 0)
377 die("diff setup failed");
378 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
379 diffcore_std(&opts);
380 for (i = 0; i < diff_queued_diff.nr; ++i) {
381 struct path_list_item *item;
382 struct rename *re;
383 struct diff_filepair *pair = diff_queued_diff.queue[i];
384 if (pair->status != 'R') {
385 diff_free_filepair(pair);
386 continue;
387 }
388 re = xmalloc(sizeof(*re));
389 re->processed = 0;
390 re->pair = pair;
391 item = path_list_lookup(re->pair->one->path, entries);
392 if (!item)
393 re->src_entry = insert_stage_data(re->pair->one->path,
394 o_tree, a_tree, b_tree, entries);
395 else
396 re->src_entry = item->util;
397
398 item = path_list_lookup(re->pair->two->path, entries);
399 if (!item)
400 re->dst_entry = insert_stage_data(re->pair->two->path,
401 o_tree, a_tree, b_tree, entries);
402 else
403 re->dst_entry = item->util;
404 item = path_list_insert(pair->one->path, renames);
405 item->util = re;
406 }
407 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
408 diff_queued_diff.nr = 0;
409 diff_flush(&opts);
410 return renames;
411 }
412
413 static int update_stages(const char *path, struct diff_filespec *o,
414 struct diff_filespec *a, struct diff_filespec *b,
415 int clear)
416 {
417 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
418 if (clear)
419 if (remove_file_from_cache(path))
420 return -1;
421 if (o)
422 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
423 return -1;
424 if (a)
425 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
426 return -1;
427 if (b)
428 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
429 return -1;
430 return 0;
431 }
432
433 static int remove_path(const char *name)
434 {
435 int ret, len;
436 char *slash, *dirs;
437
438 ret = unlink(name);
439 if (ret)
440 return ret;
441 len = strlen(name);
442 dirs = xmalloc(len+1);
443 memcpy(dirs, name, len);
444 dirs[len] = '\0';
445 while ((slash = strrchr(name, '/'))) {
446 *slash = '\0';
447 len = slash - name;
448 if (rmdir(name) != 0)
449 break;
450 }
451 free(dirs);
452 return ret;
453 }
454
455 static int remove_file(int clean, const char *path, int no_wd)
456 {
457 int update_cache = index_only || clean;
458 int update_working_directory = !index_only && !no_wd;
459
460 if (update_cache) {
461 if (remove_file_from_cache(path))
462 return -1;
463 }
464 if (update_working_directory) {
465 unlink(path);
466 if (errno != ENOENT || errno != EISDIR)
467 return -1;
468 remove_path(path);
469 }
470 return 0;
471 }
472
473 static char *unique_path(const char *path, const char *branch)
474 {
475 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
476 int suffix = 0;
477 struct stat st;
478 char *p = newpath + strlen(path);
479 strcpy(newpath, path);
480 *(p++) = '~';
481 strcpy(p, branch);
482 for (; *p; ++p)
483 if ('/' == *p)
484 *p = '_';
485 while (path_list_has_path(&current_file_set, newpath) ||
486 path_list_has_path(&current_directory_set, newpath) ||
487 lstat(newpath, &st) == 0)
488 sprintf(p, "_%d", suffix++);
489
490 path_list_insert(newpath, &current_file_set);
491 return newpath;
492 }
493
494 static int mkdir_p(const char *path, unsigned long mode)
495 {
496 /* path points to cache entries, so xstrdup before messing with it */
497 char *buf = xstrdup(path);
498 int result = safe_create_leading_directories(buf);
499 free(buf);
500 return result;
501 }
502
503 static void flush_buffer(int fd, const char *buf, unsigned long size)
504 {
505 while (size > 0) {
506 long ret = write_in_full(fd, buf, size);
507 if (ret < 0) {
508 /* Ignore epipe */
509 if (errno == EPIPE)
510 break;
511 die("merge-recursive: %s", strerror(errno));
512 } else if (!ret) {
513 die("merge-recursive: disk full?");
514 }
515 size -= ret;
516 buf += ret;
517 }
518 }
519
520 static int make_room_for_path(const char *path)
521 {
522 int status;
523 const char *msg = "failed to create path '%s'%s";
524
525 status = mkdir_p(path, 0777);
526 if (status) {
527 if (status == -3) {
528 /* something else exists */
529 error(msg, path, ": perhaps a D/F conflict?");
530 return -1;
531 }
532 die(msg, path, "");
533 }
534
535 /* Successful unlink is good.. */
536 if (!unlink(path))
537 return 0;
538 /* .. and so is no existing file */
539 if (errno == ENOENT)
540 return 0;
541 /* .. but not some other error (who really cares what?) */
542 return error(msg, path, ": perhaps a D/F conflict?");
543 }
544
545 static void update_file_flags(const unsigned char *sha,
546 unsigned mode,
547 const char *path,
548 int update_cache,
549 int update_wd)
550 {
551 if (index_only)
552 update_wd = 0;
553
554 if (update_wd) {
555 enum object_type type;
556 void *buf;
557 unsigned long size;
558
559 buf = read_sha1_file(sha, &type, &size);
560 if (!buf)
561 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
562 if (type != OBJ_BLOB)
563 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
564
565 if (make_room_for_path(path) < 0) {
566 update_wd = 0;
567 goto update_index;
568 }
569 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
570 int fd;
571 if (mode & 0100)
572 mode = 0777;
573 else
574 mode = 0666;
575 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
576 if (fd < 0)
577 die("failed to open %s: %s", path, strerror(errno));
578 flush_buffer(fd, buf, size);
579 close(fd);
580 } else if (S_ISLNK(mode)) {
581 char *lnk = xmalloc(size + 1);
582 memcpy(lnk, buf, size);
583 lnk[size] = '\0';
584 mkdir_p(path, 0777);
585 unlink(path);
586 symlink(lnk, path);
587 free(lnk);
588 } else
589 die("do not know what to do with %06o %s '%s'",
590 mode, sha1_to_hex(sha), path);
591 }
592 update_index:
593 if (update_cache)
594 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
595 }
596
597 static void update_file(int clean,
598 const unsigned char *sha,
599 unsigned mode,
600 const char *path)
601 {
602 update_file_flags(sha, mode, path, index_only || clean, !index_only);
603 }
604
605 /* Low level file merging, update and removal */
606
607 struct merge_file_info
608 {
609 unsigned char sha[20];
610 unsigned mode;
611 unsigned clean:1,
612 merge:1;
613 };
614
615 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
616 {
617 unsigned long size;
618 enum object_type type;
619
620 if (!hashcmp(sha1, null_sha1)) {
621 mm->ptr = xstrdup("");
622 mm->size = 0;
623 return;
624 }
625
626 mm->ptr = read_sha1_file(sha1, &type, &size);
627 if (!mm->ptr || type != OBJ_BLOB)
628 die("unable to read blob object %s", sha1_to_hex(sha1));
629 mm->size = size;
630 }
631
632 /*
633 * Customizable low-level merge drivers support.
634 */
635
636 struct ll_merge_driver;
637 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
638 const char *path,
639 mmfile_t *orig,
640 mmfile_t *src1, const char *name1,
641 mmfile_t *src2, const char *name2,
642 mmbuffer_t *result);
643
644 struct ll_merge_driver {
645 const char *name;
646 const char *description;
647 ll_merge_fn fn;
648 const char *recursive;
649 struct ll_merge_driver *next;
650 char *cmdline;
651 };
652
653 /*
654 * Built-in low-levels
655 */
656 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
657 const char *path_unused,
658 mmfile_t *orig,
659 mmfile_t *src1, const char *name1,
660 mmfile_t *src2, const char *name2,
661 mmbuffer_t *result)
662 {
663 /*
664 * The tentative merge result is "ours" for the final round,
665 * or common ancestor for an internal merge. Still return
666 * "conflicted merge" status.
667 */
668 mmfile_t *stolen = index_only ? orig : src1;
669
670 result->ptr = stolen->ptr;
671 result->size = stolen->size;
672 stolen->ptr = NULL;
673 return 1;
674 }
675
676 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
677 const char *path_unused,
678 mmfile_t *orig,
679 mmfile_t *src1, const char *name1,
680 mmfile_t *src2, const char *name2,
681 mmbuffer_t *result)
682 {
683 xpparam_t xpp;
684
685 if (buffer_is_binary(orig->ptr, orig->size) ||
686 buffer_is_binary(src1->ptr, src1->size) ||
687 buffer_is_binary(src2->ptr, src2->size)) {
688 warning("Cannot merge binary files: %s vs. %s\n",
689 name1, name2);
690 return ll_binary_merge(drv_unused, path_unused,
691 orig, src1, name1,
692 src2, name2,
693 result);
694 }
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 #define LL_BINARY_MERGE 0
748 #define LL_TEXT_MERGE 1
749 #define LL_UNION_MERGE 2
750 static struct ll_merge_driver ll_merge_drv[] = {
751 { "binary", "built-in binary merge", ll_binary_merge },
752 { "text", "built-in 3-way text merge", ll_xdl_merge },
753 { "union", "built-in union merge", ll_union_merge },
754 };
755
756 static void create_temp(mmfile_t *src, char *path)
757 {
758 int fd;
759
760 strcpy(path, ".merge_file_XXXXXX");
761 fd = xmkstemp(path);
762 if (write_in_full(fd, src->ptr, src->size) != src->size)
763 die("unable to write temp-file");
764 close(fd);
765 }
766
767 /*
768 * User defined low-level merge driver support.
769 */
770 static int ll_ext_merge(const struct ll_merge_driver *fn,
771 const char *path,
772 mmfile_t *orig,
773 mmfile_t *src1, const char *name1,
774 mmfile_t *src2, const char *name2,
775 mmbuffer_t *result)
776 {
777 char temp[3][50];
778 char cmdbuf[2048];
779 struct interp table[] = {
780 { "%O" },
781 { "%A" },
782 { "%B" },
783 };
784 struct child_process child;
785 const char *args[20];
786 int status, fd, i;
787 struct stat st;
788
789 if (fn->cmdline == NULL)
790 die("custom merge driver %s lacks command line.", fn->name);
791
792 result->ptr = NULL;
793 result->size = 0;
794 create_temp(orig, temp[0]);
795 create_temp(src1, temp[1]);
796 create_temp(src2, temp[2]);
797
798 interp_set_entry(table, 0, temp[0]);
799 interp_set_entry(table, 1, temp[1]);
800 interp_set_entry(table, 2, temp[2]);
801
802 output(1, "merging %s using %s", path,
803 fn->description ? fn->description : fn->name);
804
805 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
806
807 memset(&child, 0, sizeof(child));
808 child.argv = args;
809 args[0] = "sh";
810 args[1] = "-c";
811 args[2] = cmdbuf;
812 args[3] = NULL;
813
814 status = run_command(&child);
815 if (status < -ERR_RUN_COMMAND_FORK)
816 ; /* failure in run-command */
817 else
818 status = -status;
819 fd = open(temp[1], O_RDONLY);
820 if (fd < 0)
821 goto bad;
822 if (fstat(fd, &st))
823 goto close_bad;
824 result->size = st.st_size;
825 result->ptr = xmalloc(result->size + 1);
826 if (read_in_full(fd, result->ptr, result->size) != result->size) {
827 free(result->ptr);
828 result->ptr = NULL;
829 result->size = 0;
830 }
831 close_bad:
832 close(fd);
833 bad:
834 for (i = 0; i < 3; i++)
835 unlink(temp[i]);
836 return status;
837 }
838
839 /*
840 * merge.default and merge.driver configuration items
841 */
842 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
843 static const char *default_ll_merge;
844
845 static int read_merge_config(const char *var, const char *value)
846 {
847 struct ll_merge_driver *fn;
848 const char *ep, *name;
849 int namelen;
850
851 if (!strcmp(var, "merge.default")) {
852 if (value)
853 default_ll_merge = strdup(value);
854 return 0;
855 }
856
857 /*
858 * We are not interested in anything but "merge.<name>.variable";
859 * especially, we do not want to look at variables such as
860 * "merge.summary", "merge.tool", and "merge.verbosity".
861 */
862 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
863 return 0;
864
865 /*
866 * Find existing one as we might be processing merge.<name>.var2
867 * after seeing merge.<name>.var1.
868 */
869 name = var + 6;
870 namelen = ep - name;
871 for (fn = ll_user_merge; fn; fn = fn->next)
872 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
873 break;
874 if (!fn) {
875 char *namebuf;
876 fn = xcalloc(1, sizeof(struct ll_merge_driver));
877 namebuf = xmalloc(namelen + 1);
878 memcpy(namebuf, name, namelen);
879 namebuf[namelen] = 0;
880 fn->name = namebuf;
881 fn->fn = ll_ext_merge;
882 fn->next = NULL;
883 *ll_user_merge_tail = fn;
884 ll_user_merge_tail = &(fn->next);
885 }
886
887 ep++;
888
889 if (!strcmp("name", ep)) {
890 if (!value)
891 return error("%s: lacks value", var);
892 fn->description = strdup(value);
893 return 0;
894 }
895
896 if (!strcmp("driver", ep)) {
897 if (!value)
898 return error("%s: lacks value", var);
899 /*
900 * merge.<name>.driver specifies the command line:
901 *
902 * command-line
903 *
904 * The command-line will be interpolated with the following
905 * tokens and is given to the shell:
906 *
907 * %O - temporary file name for the merge base.
908 * %A - temporary file name for our version.
909 * %B - temporary file name for the other branches' version.
910 *
911 * The external merge driver should write the results in the
912 * file named by %A, and signal that it has done with zero exit
913 * status.
914 */
915 fn->cmdline = strdup(value);
916 return 0;
917 }
918
919 if (!strcmp("recursive", ep)) {
920 if (!value)
921 return error("%s: lacks value", var);
922 fn->recursive = strdup(value);
923 return 0;
924 }
925
926 return 0;
927 }
928
929 static void initialize_ll_merge(void)
930 {
931 if (ll_user_merge_tail)
932 return;
933 ll_user_merge_tail = &ll_user_merge;
934 git_config(read_merge_config);
935 }
936
937 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
938 {
939 struct ll_merge_driver *fn;
940 const char *name;
941 int i;
942
943 initialize_ll_merge();
944
945 if (ATTR_TRUE(merge_attr))
946 return &ll_merge_drv[LL_TEXT_MERGE];
947 else if (ATTR_FALSE(merge_attr))
948 return &ll_merge_drv[LL_BINARY_MERGE];
949 else if (ATTR_UNSET(merge_attr)) {
950 if (!default_ll_merge)
951 return &ll_merge_drv[LL_TEXT_MERGE];
952 else
953 name = default_ll_merge;
954 }
955 else
956 name = merge_attr;
957
958 for (fn = ll_user_merge; fn; fn = fn->next)
959 if (!strcmp(fn->name, name))
960 return fn;
961
962 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
963 if (!strcmp(ll_merge_drv[i].name, name))
964 return &ll_merge_drv[i];
965
966 /* default to the 3-way */
967 return &ll_merge_drv[LL_TEXT_MERGE];
968 }
969
970 static const char *git_path_check_merge(const char *path)
971 {
972 static struct git_attr_check attr_merge_check;
973
974 if (!attr_merge_check.attr)
975 attr_merge_check.attr = git_attr("merge", 5);
976
977 if (git_checkattr(path, 1, &attr_merge_check))
978 return NULL;
979 return attr_merge_check.value;
980 }
981
982 static int ll_merge(mmbuffer_t *result_buf,
983 struct diff_filespec *o,
984 struct diff_filespec *a,
985 struct diff_filespec *b,
986 const char *branch1,
987 const char *branch2)
988 {
989 mmfile_t orig, src1, src2;
990 char *name1, *name2;
991 int merge_status;
992 const char *ll_driver_name;
993 const struct ll_merge_driver *driver;
994
995 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
996 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
997
998 fill_mm(o->sha1, &orig);
999 fill_mm(a->sha1, &src1);
1000 fill_mm(b->sha1, &src2);
1001
1002 ll_driver_name = git_path_check_merge(a->path);
1003 driver = find_ll_merge_driver(ll_driver_name);
1004
1005 if (index_only && driver->recursive)
1006 driver = find_ll_merge_driver(driver->recursive);
1007 merge_status = driver->fn(driver, a->path,
1008 &orig, &src1, name1, &src2, name2,
1009 result_buf);
1010
1011 free(name1);
1012 free(name2);
1013 free(orig.ptr);
1014 free(src1.ptr);
1015 free(src2.ptr);
1016 return merge_status;
1017 }
1018
1019 static struct merge_file_info merge_file(struct diff_filespec *o,
1020 struct diff_filespec *a, struct diff_filespec *b,
1021 const char *branch1, const char *branch2)
1022 {
1023 struct merge_file_info result;
1024 result.merge = 0;
1025 result.clean = 1;
1026
1027 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1028 result.clean = 0;
1029 if (S_ISREG(a->mode)) {
1030 result.mode = a->mode;
1031 hashcpy(result.sha, a->sha1);
1032 } else {
1033 result.mode = b->mode;
1034 hashcpy(result.sha, b->sha1);
1035 }
1036 } else {
1037 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1038 result.merge = 1;
1039
1040 result.mode = a->mode == o->mode ? b->mode: a->mode;
1041
1042 if (sha_eq(a->sha1, o->sha1))
1043 hashcpy(result.sha, b->sha1);
1044 else if (sha_eq(b->sha1, o->sha1))
1045 hashcpy(result.sha, a->sha1);
1046 else if (S_ISREG(a->mode)) {
1047 mmbuffer_t result_buf;
1048 int merge_status;
1049
1050 merge_status = ll_merge(&result_buf, o, a, b,
1051 branch1, branch2);
1052
1053 if ((merge_status < 0) || !result_buf.ptr)
1054 die("Failed to execute internal merge");
1055
1056 if (write_sha1_file(result_buf.ptr, result_buf.size,
1057 blob_type, result.sha))
1058 die("Unable to add %s to database",
1059 a->path);
1060
1061 free(result_buf.ptr);
1062 result.clean = (merge_status == 0);
1063 } else {
1064 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1065 die("cannot merge modes?");
1066
1067 hashcpy(result.sha, a->sha1);
1068
1069 if (!sha_eq(a->sha1, b->sha1))
1070 result.clean = 0;
1071 }
1072 }
1073
1074 return result;
1075 }
1076
1077 static void conflict_rename_rename(struct rename *ren1,
1078 const char *branch1,
1079 struct rename *ren2,
1080 const char *branch2)
1081 {
1082 char *del[2];
1083 int delp = 0;
1084 const char *ren1_dst = ren1->pair->two->path;
1085 const char *ren2_dst = ren2->pair->two->path;
1086 const char *dst_name1 = ren1_dst;
1087 const char *dst_name2 = ren2_dst;
1088 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1089 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1090 output(1, "%s is a directory in %s added as %s instead",
1091 ren1_dst, branch2, dst_name1);
1092 remove_file(0, ren1_dst, 0);
1093 }
1094 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1095 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1096 output(1, "%s is a directory in %s added as %s instead",
1097 ren2_dst, branch1, dst_name2);
1098 remove_file(0, ren2_dst, 0);
1099 }
1100 if (index_only) {
1101 remove_file_from_cache(dst_name1);
1102 remove_file_from_cache(dst_name2);
1103 /*
1104 * Uncomment to leave the conflicting names in the resulting tree
1105 *
1106 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1107 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1108 */
1109 } else {
1110 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1111 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1112 }
1113 while (delp--)
1114 free(del[delp]);
1115 }
1116
1117 static void conflict_rename_dir(struct rename *ren1,
1118 const char *branch1)
1119 {
1120 char *new_path = unique_path(ren1->pair->two->path, branch1);
1121 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1122 remove_file(0, ren1->pair->two->path, 0);
1123 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1124 free(new_path);
1125 }
1126
1127 static void conflict_rename_rename_2(struct rename *ren1,
1128 const char *branch1,
1129 struct rename *ren2,
1130 const char *branch2)
1131 {
1132 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1133 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1134 output(1, "Renamed %s to %s and %s to %s instead",
1135 ren1->pair->one->path, new_path1,
1136 ren2->pair->one->path, new_path2);
1137 remove_file(0, ren1->pair->two->path, 0);
1138 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1139 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1140 free(new_path2);
1141 free(new_path1);
1142 }
1143
1144 static int process_renames(struct path_list *a_renames,
1145 struct path_list *b_renames,
1146 const char *a_branch,
1147 const char *b_branch)
1148 {
1149 int clean_merge = 1, i, j;
1150 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1151 const struct rename *sre;
1152
1153 for (i = 0; i < a_renames->nr; i++) {
1154 sre = a_renames->items[i].util;
1155 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1156 = sre->dst_entry;
1157 }
1158 for (i = 0; i < b_renames->nr; i++) {
1159 sre = b_renames->items[i].util;
1160 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1161 = sre->dst_entry;
1162 }
1163
1164 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1165 int compare;
1166 char *src;
1167 struct path_list *renames1, *renames2, *renames2Dst;
1168 struct rename *ren1 = NULL, *ren2 = NULL;
1169 const char *branch1, *branch2;
1170 const char *ren1_src, *ren1_dst;
1171
1172 if (i >= a_renames->nr) {
1173 compare = 1;
1174 ren2 = b_renames->items[j++].util;
1175 } else if (j >= b_renames->nr) {
1176 compare = -1;
1177 ren1 = a_renames->items[i++].util;
1178 } else {
1179 compare = strcmp(a_renames->items[i].path,
1180 b_renames->items[j].path);
1181 if (compare <= 0)
1182 ren1 = a_renames->items[i++].util;
1183 if (compare >= 0)
1184 ren2 = b_renames->items[j++].util;
1185 }
1186
1187 /* TODO: refactor, so that 1/2 are not needed */
1188 if (ren1) {
1189 renames1 = a_renames;
1190 renames2 = b_renames;
1191 renames2Dst = &b_by_dst;
1192 branch1 = a_branch;
1193 branch2 = b_branch;
1194 } else {
1195 struct rename *tmp;
1196 renames1 = b_renames;
1197 renames2 = a_renames;
1198 renames2Dst = &a_by_dst;
1199 branch1 = b_branch;
1200 branch2 = a_branch;
1201 tmp = ren2;
1202 ren2 = ren1;
1203 ren1 = tmp;
1204 }
1205 src = ren1->pair->one->path;
1206
1207 ren1->dst_entry->processed = 1;
1208 ren1->src_entry->processed = 1;
1209
1210 if (ren1->processed)
1211 continue;
1212 ren1->processed = 1;
1213
1214 ren1_src = ren1->pair->one->path;
1215 ren1_dst = ren1->pair->two->path;
1216
1217 if (ren2) {
1218 const char *ren2_src = ren2->pair->one->path;
1219 const char *ren2_dst = ren2->pair->two->path;
1220 /* Renamed in 1 and renamed in 2 */
1221 if (strcmp(ren1_src, ren2_src) != 0)
1222 die("ren1.src != ren2.src");
1223 ren2->dst_entry->processed = 1;
1224 ren2->processed = 1;
1225 if (strcmp(ren1_dst, ren2_dst) != 0) {
1226 clean_merge = 0;
1227 output(1, "CONFLICT (rename/rename): "
1228 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1229 "rename \"%s\"->\"%s\" in \"%s\"%s",
1230 src, ren1_dst, branch1,
1231 src, ren2_dst, branch2,
1232 index_only ? " (left unresolved)": "");
1233 if (index_only) {
1234 remove_file_from_cache(src);
1235 update_file(0, ren1->pair->one->sha1,
1236 ren1->pair->one->mode, src);
1237 }
1238 conflict_rename_rename(ren1, branch1, ren2, branch2);
1239 } else {
1240 struct merge_file_info mfi;
1241 remove_file(1, ren1_src, 1);
1242 mfi = merge_file(ren1->pair->one,
1243 ren1->pair->two,
1244 ren2->pair->two,
1245 branch1,
1246 branch2);
1247 if (mfi.merge || !mfi.clean)
1248 output(1, "Renamed %s->%s", src, ren1_dst);
1249
1250 if (mfi.merge)
1251 output(2, "Auto-merged %s", ren1_dst);
1252
1253 if (!mfi.clean) {
1254 output(1, "CONFLICT (content): merge conflict in %s",
1255 ren1_dst);
1256 clean_merge = 0;
1257
1258 if (!index_only)
1259 update_stages(ren1_dst,
1260 ren1->pair->one,
1261 ren1->pair->two,
1262 ren2->pair->two,
1263 1 /* clear */);
1264 }
1265 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1266 }
1267 } else {
1268 /* Renamed in 1, maybe changed in 2 */
1269 struct path_list_item *item;
1270 /* we only use sha1 and mode of these */
1271 struct diff_filespec src_other, dst_other;
1272 int try_merge, stage = a_renames == renames1 ? 3: 2;
1273
1274 remove_file(1, ren1_src, index_only || stage == 3);
1275
1276 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1277 src_other.mode = ren1->src_entry->stages[stage].mode;
1278 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1279 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1280
1281 try_merge = 0;
1282
1283 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1284 clean_merge = 0;
1285 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1286 " directory %s added in %s",
1287 ren1_src, ren1_dst, branch1,
1288 ren1_dst, branch2);
1289 conflict_rename_dir(ren1, branch1);
1290 } else if (sha_eq(src_other.sha1, null_sha1)) {
1291 clean_merge = 0;
1292 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1293 "and deleted in %s",
1294 ren1_src, ren1_dst, branch1,
1295 branch2);
1296 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1297 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1298 const char *new_path;
1299 clean_merge = 0;
1300 try_merge = 1;
1301 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1302 "%s added in %s",
1303 ren1_src, ren1_dst, branch1,
1304 ren1_dst, branch2);
1305 new_path = unique_path(ren1_dst, branch2);
1306 output(1, "Added as %s instead", new_path);
1307 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1308 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1309 ren2 = item->util;
1310 clean_merge = 0;
1311 ren2->processed = 1;
1312 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1313 "Renamed %s->%s in %s",
1314 ren1_src, ren1_dst, branch1,
1315 ren2->pair->one->path, ren2->pair->two->path, branch2);
1316 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1317 } else
1318 try_merge = 1;
1319
1320 if (try_merge) {
1321 struct diff_filespec *o, *a, *b;
1322 struct merge_file_info mfi;
1323 src_other.path = (char *)ren1_src;
1324
1325 o = ren1->pair->one;
1326 if (a_renames == renames1) {
1327 a = ren1->pair->two;
1328 b = &src_other;
1329 } else {
1330 b = ren1->pair->two;
1331 a = &src_other;
1332 }
1333 mfi = merge_file(o, a, b,
1334 a_branch, b_branch);
1335
1336 if (mfi.clean &&
1337 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1338 mfi.mode == ren1->pair->two->mode)
1339 /*
1340 * This messaged is part of
1341 * t6022 test. If you change
1342 * it update the test too.
1343 */
1344 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1345 else {
1346 if (mfi.merge || !mfi.clean)
1347 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1348 if (mfi.merge)
1349 output(2, "Auto-merged %s", ren1_dst);
1350 if (!mfi.clean) {
1351 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1352 ren1_dst);
1353 clean_merge = 0;
1354
1355 if (!index_only)
1356 update_stages(ren1_dst,
1357 o, a, b, 1);
1358 }
1359 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1360 }
1361 }
1362 }
1363 }
1364 path_list_clear(&a_by_dst, 0);
1365 path_list_clear(&b_by_dst, 0);
1366
1367 return clean_merge;
1368 }
1369
1370 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1371 {
1372 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1373 }
1374
1375 /* Per entry merge function */
1376 static int process_entry(const char *path, struct stage_data *entry,
1377 const char *branch1,
1378 const char *branch2)
1379 {
1380 /*
1381 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1382 print_index_entry("\tpath: ", entry);
1383 */
1384 int clean_merge = 1;
1385 unsigned o_mode = entry->stages[1].mode;
1386 unsigned a_mode = entry->stages[2].mode;
1387 unsigned b_mode = entry->stages[3].mode;
1388 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1389 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1390 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1391
1392 if (o_sha && (!a_sha || !b_sha)) {
1393 /* Case A: Deleted in one */
1394 if ((!a_sha && !b_sha) ||
1395 (sha_eq(a_sha, o_sha) && !b_sha) ||
1396 (!a_sha && sha_eq(b_sha, o_sha))) {
1397 /* Deleted in both or deleted in one and
1398 * unchanged in the other */
1399 if (a_sha)
1400 output(2, "Removed %s", path);
1401 /* do not touch working file if it did not exist */
1402 remove_file(1, path, !a_sha);
1403 } else {
1404 /* Deleted in one and changed in the other */
1405 clean_merge = 0;
1406 if (!a_sha) {
1407 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1408 "and modified in %s. Version %s of %s left in tree.",
1409 path, branch1,
1410 branch2, branch2, path);
1411 update_file(0, b_sha, b_mode, path);
1412 } else {
1413 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1414 "and modified in %s. Version %s of %s left in tree.",
1415 path, branch2,
1416 branch1, branch1, path);
1417 update_file(0, a_sha, a_mode, path);
1418 }
1419 }
1420
1421 } else if ((!o_sha && a_sha && !b_sha) ||
1422 (!o_sha && !a_sha && b_sha)) {
1423 /* Case B: Added in one. */
1424 const char *add_branch;
1425 const char *other_branch;
1426 unsigned mode;
1427 const unsigned char *sha;
1428 const char *conf;
1429
1430 if (a_sha) {
1431 add_branch = branch1;
1432 other_branch = branch2;
1433 mode = a_mode;
1434 sha = a_sha;
1435 conf = "file/directory";
1436 } else {
1437 add_branch = branch2;
1438 other_branch = branch1;
1439 mode = b_mode;
1440 sha = b_sha;
1441 conf = "directory/file";
1442 }
1443 if (path_list_has_path(&current_directory_set, path)) {
1444 const char *new_path = unique_path(path, add_branch);
1445 clean_merge = 0;
1446 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1447 "Added %s as %s",
1448 conf, path, other_branch, path, new_path);
1449 remove_file(0, path, 0);
1450 update_file(0, sha, mode, new_path);
1451 } else {
1452 output(2, "Added %s", path);
1453 update_file(1, sha, mode, path);
1454 }
1455 } else if (a_sha && b_sha) {
1456 /* Case C: Added in both (check for same permissions) and */
1457 /* case D: Modified in both, but differently. */
1458 const char *reason = "content";
1459 struct merge_file_info mfi;
1460 struct diff_filespec o, a, b;
1461
1462 if (!o_sha) {
1463 reason = "add/add";
1464 o_sha = (unsigned char *)null_sha1;
1465 }
1466 output(2, "Auto-merged %s", path);
1467 o.path = a.path = b.path = (char *)path;
1468 hashcpy(o.sha1, o_sha);
1469 o.mode = o_mode;
1470 hashcpy(a.sha1, a_sha);
1471 a.mode = a_mode;
1472 hashcpy(b.sha1, b_sha);
1473 b.mode = b_mode;
1474
1475 mfi = merge_file(&o, &a, &b,
1476 branch1, branch2);
1477
1478 if (mfi.clean)
1479 update_file(1, mfi.sha, mfi.mode, path);
1480 else {
1481 clean_merge = 0;
1482 output(1, "CONFLICT (%s): Merge conflict in %s",
1483 reason, path);
1484
1485 if (index_only)
1486 update_file(0, mfi.sha, mfi.mode, path);
1487 else
1488 update_file_flags(mfi.sha, mfi.mode, path,
1489 0 /* update_cache */, 1 /* update_working_directory */);
1490 }
1491 } else if (!o_sha && !a_sha && !b_sha) {
1492 /*
1493 * this entry was deleted altogether. a_mode == 0 means
1494 * we had that path and want to actively remove it.
1495 */
1496 remove_file(1, path, !a_mode);
1497 } else
1498 die("Fatal merge failure, shouldn't happen.");
1499
1500 return clean_merge;
1501 }
1502
1503 static int merge_trees(struct tree *head,
1504 struct tree *merge,
1505 struct tree *common,
1506 const char *branch1,
1507 const char *branch2,
1508 struct tree **result)
1509 {
1510 int code, clean;
1511
1512 if (subtree_merge) {
1513 merge = shift_tree_object(head, merge);
1514 common = shift_tree_object(head, common);
1515 }
1516
1517 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1518 output(0, "Already uptodate!");
1519 *result = head;
1520 return 1;
1521 }
1522
1523 code = git_merge_trees(index_only, common, head, merge);
1524
1525 if (code != 0)
1526 die("merging of trees %s and %s failed",
1527 sha1_to_hex(head->object.sha1),
1528 sha1_to_hex(merge->object.sha1));
1529
1530 if (unmerged_index()) {
1531 struct path_list *entries, *re_head, *re_merge;
1532 int i;
1533 path_list_clear(&current_file_set, 1);
1534 path_list_clear(&current_directory_set, 1);
1535 get_files_dirs(head);
1536 get_files_dirs(merge);
1537
1538 entries = get_unmerged();
1539 re_head = get_renames(head, common, head, merge, entries);
1540 re_merge = get_renames(merge, common, head, merge, entries);
1541 clean = process_renames(re_head, re_merge,
1542 branch1, branch2);
1543 for (i = 0; i < entries->nr; i++) {
1544 const char *path = entries->items[i].path;
1545 struct stage_data *e = entries->items[i].util;
1546 if (!e->processed
1547 && !process_entry(path, e, branch1, branch2))
1548 clean = 0;
1549 }
1550
1551 path_list_clear(re_merge, 0);
1552 path_list_clear(re_head, 0);
1553 path_list_clear(entries, 1);
1554
1555 }
1556 else
1557 clean = 1;
1558
1559 if (index_only)
1560 *result = git_write_tree();
1561
1562 return clean;
1563 }
1564
1565 static struct commit_list *reverse_commit_list(struct commit_list *list)
1566 {
1567 struct commit_list *next = NULL, *current, *backup;
1568 for (current = list; current; current = backup) {
1569 backup = current->next;
1570 current->next = next;
1571 next = current;
1572 }
1573 return next;
1574 }
1575
1576 /*
1577 * Merge the commits h1 and h2, return the resulting virtual
1578 * commit object and a flag indicating the cleanness of the merge.
1579 */
1580 static int merge(struct commit *h1,
1581 struct commit *h2,
1582 const char *branch1,
1583 const char *branch2,
1584 struct commit_list *ca,
1585 struct commit **result)
1586 {
1587 struct commit_list *iter;
1588 struct commit *merged_common_ancestors;
1589 struct tree *mrtree;
1590 int clean;
1591
1592 if (show(4)) {
1593 output(4, "Merging:");
1594 output_commit_title(h1);
1595 output_commit_title(h2);
1596 }
1597
1598 if (!ca) {
1599 ca = get_merge_bases(h1, h2, 1);
1600 ca = reverse_commit_list(ca);
1601 }
1602
1603 if (show(5)) {
1604 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1605 for (iter = ca; iter; iter = iter->next)
1606 output_commit_title(iter->item);
1607 }
1608
1609 merged_common_ancestors = pop_commit(&ca);
1610 if (merged_common_ancestors == NULL) {
1611 /* if there is no common ancestor, make an empty tree */
1612 struct tree *tree = xcalloc(1, sizeof(struct tree));
1613
1614 tree->object.parsed = 1;
1615 tree->object.type = OBJ_TREE;
1616 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1617 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1618 }
1619
1620 for (iter = ca; iter; iter = iter->next) {
1621 call_depth++;
1622 /*
1623 * When the merge fails, the result contains files
1624 * with conflict markers. The cleanness flag is
1625 * ignored, it was never actually used, as result of
1626 * merge_trees has always overwritten it: the committed
1627 * "conflicts" were already resolved.
1628 */
1629 discard_cache();
1630 merge(merged_common_ancestors, iter->item,
1631 "Temporary merge branch 1",
1632 "Temporary merge branch 2",
1633 NULL,
1634 &merged_common_ancestors);
1635 call_depth--;
1636
1637 if (!merged_common_ancestors)
1638 die("merge returned no commit");
1639 }
1640
1641 discard_cache();
1642 if (!call_depth) {
1643 read_cache();
1644 index_only = 0;
1645 } else
1646 index_only = 1;
1647
1648 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1649 branch1, branch2, &mrtree);
1650
1651 if (index_only) {
1652 *result = make_virtual_commit(mrtree, "merged tree");
1653 commit_list_insert(h1, &(*result)->parents);
1654 commit_list_insert(h2, &(*result)->parents->next);
1655 }
1656 flush_output();
1657 return clean;
1658 }
1659
1660 static const char *better_branch_name(const char *branch)
1661 {
1662 static char githead_env[8 + 40 + 1];
1663 char *name;
1664
1665 if (strlen(branch) != 40)
1666 return branch;
1667 sprintf(githead_env, "GITHEAD_%s", branch);
1668 name = getenv(githead_env);
1669 return name ? name : branch;
1670 }
1671
1672 static struct commit *get_ref(const char *ref)
1673 {
1674 unsigned char sha1[20];
1675 struct object *object;
1676
1677 if (get_sha1(ref, sha1))
1678 die("Could not resolve ref '%s'", ref);
1679 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1680 if (object->type == OBJ_TREE)
1681 return make_virtual_commit((struct tree*)object,
1682 better_branch_name(ref));
1683 if (object->type != OBJ_COMMIT)
1684 return NULL;
1685 if (parse_commit((struct commit *)object))
1686 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1687 return (struct commit *)object;
1688 }
1689
1690 static int merge_config(const char *var, const char *value)
1691 {
1692 if (!strcasecmp(var, "merge.verbosity")) {
1693 verbosity = git_config_int(var, value);
1694 return 0;
1695 }
1696 return git_default_config(var, value);
1697 }
1698
1699 int main(int argc, char *argv[])
1700 {
1701 static const char *bases[20];
1702 static unsigned bases_count = 0;
1703 int i, clean;
1704 const char *branch1, *branch2;
1705 struct commit *result, *h1, *h2;
1706 struct commit_list *ca = NULL;
1707 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1708 int index_fd;
1709
1710 if (argv[0]) {
1711 int namelen = strlen(argv[0]);
1712 if (8 < namelen &&
1713 !strcmp(argv[0] + namelen - 8, "-subtree"))
1714 subtree_merge = 1;
1715 }
1716
1717 git_config(merge_config);
1718 if (getenv("GIT_MERGE_VERBOSITY"))
1719 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1720
1721 if (argc < 4)
1722 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1723
1724 for (i = 1; i < argc; ++i) {
1725 if (!strcmp(argv[i], "--"))
1726 break;
1727 if (bases_count < sizeof(bases)/sizeof(*bases))
1728 bases[bases_count++] = argv[i];
1729 }
1730 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1731 die("Not handling anything other than two heads merge.");
1732 if (verbosity >= 5)
1733 buffer_output = 0;
1734
1735 branch1 = argv[++i];
1736 branch2 = argv[++i];
1737
1738 h1 = get_ref(branch1);
1739 h2 = get_ref(branch2);
1740
1741 branch1 = better_branch_name(branch1);
1742 branch2 = better_branch_name(branch2);
1743
1744 if (show(3))
1745 printf("Merging %s with %s\n", branch1, branch2);
1746
1747 index_fd = hold_locked_index(lock, 1);
1748
1749 for (i = 0; i < bases_count; i++) {
1750 struct commit *ancestor = get_ref(bases[i]);
1751 ca = commit_list_insert(ancestor, &ca);
1752 }
1753 clean = merge(h1, h2, branch1, branch2, ca, &result);
1754
1755 if (active_cache_changed &&
1756 (write_cache(index_fd, active_cache, active_nr) ||
1757 close(index_fd) || commit_locked_index(lock)))
1758 die ("unable to write %s", get_index_file());
1759
1760 return clean ? 0: 1;
1761 }
Jonathan Nieder’s miscellaneous git branches