Make 'unpack_trees()' have a separate source and destination index
[git/git.git] / builtin-merge-recursive.c
1 /*
2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
3 * Fredrik Kuivinen.
4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5 */
6 #include "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "run-command.h"
15 #include "tag.h"
16 #include "unpack-trees.h"
17 #include "path-list.h"
18 #include "xdiff-interface.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22
23 static int subtree_merge;
24
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27 unsigned char shifted[20];
28
29 /*
30 * NEEDSWORK: this limits the recursion depth to hardcoded
31 * value '2' to avoid excessive overhead.
32 */
33 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
34 if (!hashcmp(two->object.sha1, shifted))
35 return two;
36 return lookup_tree(shifted);
37 }
38
39 /*
40 * A virtual commit has
41 * - (const char *)commit->util set to the name, and
42 * - *(int *)commit->object.sha1 set to the virtual id.
43 */
44
45 static unsigned commit_list_count(const struct commit_list *l)
46 {
47 unsigned c = 0;
48 for (; l; l = l->next )
49 c++;
50 return c;
51 }
52
53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
54 {
55 struct commit *commit = xcalloc(1, sizeof(struct commit));
56 static unsigned virtual_id = 1;
57 commit->tree = tree;
58 commit->util = (void*)comment;
59 *(int*)commit->object.sha1 = virtual_id++;
60 /* avoid warnings */
61 commit->object.parsed = 1;
62 return commit;
63 }
64
65 /*
66 * Since we use get_tree_entry(), which does not put the read object into
67 * the object pool, we cannot rely on a == b.
68 */
69 static int sha_eq(const unsigned char *a, const unsigned char *b)
70 {
71 if (!a && !b)
72 return 2;
73 return a && b && hashcmp(a, b) == 0;
74 }
75
76 /*
77 * Since we want to write the index eventually, we cannot reuse the index
78 * for these (temporary) data.
79 */
80 struct stage_data
81 {
82 struct
83 {
84 unsigned mode;
85 unsigned char sha[20];
86 } stages[4];
87 unsigned processed:1;
88 };
89
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
92
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int rename_limit = -1;
96 static int buffer_output = 1;
97 static struct strbuf obuf = STRBUF_INIT;
98
99 static int show(int v)
100 {
101 return (!call_depth && verbosity >= v) || verbosity >= 5;
102 }
103
104 static void flush_output(void)
105 {
106 if (obuf.len) {
107 fputs(obuf.buf, stdout);
108 strbuf_reset(&obuf);
109 }
110 }
111
112 static void output(int v, const char *fmt, ...)
113 {
114 int len;
115 va_list ap;
116
117 if (!show(v))
118 return;
119
120 strbuf_grow(&obuf, call_depth * 2 + 2);
121 memset(obuf.buf + obuf.len, ' ', call_depth * 2);
122 strbuf_setlen(&obuf, obuf.len + call_depth * 2);
123
124 va_start(ap, fmt);
125 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
126 va_end(ap);
127
128 if (len < 0)
129 len = 0;
130 if (len >= strbuf_avail(&obuf)) {
131 strbuf_grow(&obuf, len + 2);
132 va_start(ap, fmt);
133 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
134 va_end(ap);
135 if (len >= strbuf_avail(&obuf)) {
136 die("this should not happen, your snprintf is broken");
137 }
138 }
139 strbuf_setlen(&obuf, obuf.len + len);
140 strbuf_add(&obuf, "\n", 1);
141 if (!buffer_output)
142 flush_output();
143 }
144
145 static void output_commit_title(struct commit *commit)
146 {
147 int i;
148 flush_output();
149 for (i = call_depth; i--;)
150 fputs(" ", stdout);
151 if (commit->util)
152 printf("virtual %s\n", (char *)commit->util);
153 else {
154 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
155 if (parse_commit(commit) != 0)
156 printf("(bad commit)\n");
157 else {
158 const char *s;
159 int len;
160 for (s = commit->buffer; *s; s++)
161 if (*s == '\n' && s[1] == '\n') {
162 s += 2;
163 break;
164 }
165 for (len = 0; s[len] && '\n' != s[len]; len++)
166 ; /* do nothing */
167 printf("%.*s\n", len, s);
168 }
169 }
170 }
171
172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
173 const char *path, int stage, int refresh, int options)
174 {
175 struct cache_entry *ce;
176 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
177 if (!ce)
178 return error("addinfo_cache failed for path '%s'", path);
179 return add_cache_entry(ce, options);
180 }
181
182 /*
183 * This is a global variable which is used in a number of places but
184 * only written to in the 'merge' function.
185 *
186 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
187 * don't update the working directory.
188 * 0 => Leave unmerged entries in the cache and update
189 * the working directory.
190 */
191 static int index_only = 0;
192
193 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
194 {
195 parse_tree(tree);
196 init_tree_desc(desc, tree->buffer, tree->size);
197 }
198
199 static int git_merge_trees(int index_only,
200 struct tree *common,
201 struct tree *head,
202 struct tree *merge)
203 {
204 int rc;
205 struct tree_desc t[3];
206 struct unpack_trees_options opts;
207
208 memset(&opts, 0, sizeof(opts));
209 if (index_only)
210 opts.index_only = 1;
211 else
212 opts.update = 1;
213 opts.merge = 1;
214 opts.head_idx = 2;
215 opts.fn = threeway_merge;
216 opts.src_index = &the_index;
217 opts.dst_index = &the_index;
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 struct tree *write_tree_from_memory(void)
229 {
230 struct tree *result = NULL;
231
232 if (unmerged_cache()) {
233 int i;
234 output(0, "There are unmerged index entries:");
235 for (i = 0; i < active_nr; i++) {
236 struct cache_entry *ce = active_cache[i];
237 if (ce_stage(ce))
238 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
239 }
240 return NULL;
241 }
242
243 if (!active_cache_tree)
244 active_cache_tree = cache_tree();
245
246 if (!cache_tree_fully_valid(active_cache_tree) &&
247 cache_tree_update(active_cache_tree,
248 active_cache, active_nr, 0, 0) < 0)
249 die("error building trees");
250
251 result = lookup_tree(active_cache_tree->sha1);
252
253 return result;
254 }
255
256 static int save_files_dirs(const unsigned char *sha1,
257 const char *base, int baselen, const char *path,
258 unsigned int mode, int stage)
259 {
260 int len = strlen(path);
261 char *newpath = xmalloc(baselen + len + 1);
262 memcpy(newpath, base, baselen);
263 memcpy(newpath + baselen, path, len);
264 newpath[baselen + len] = '\0';
265
266 if (S_ISDIR(mode))
267 path_list_insert(newpath, &current_directory_set);
268 else
269 path_list_insert(newpath, &current_file_set);
270 free(newpath);
271
272 return READ_TREE_RECURSIVE;
273 }
274
275 static int get_files_dirs(struct tree *tree)
276 {
277 int n;
278 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
279 return 0;
280 n = current_file_set.nr + current_directory_set.nr;
281 return n;
282 }
283
284 /*
285 * Returns an index_entry instance which doesn't have to correspond to
286 * a real cache entry in Git's index.
287 */
288 static struct stage_data *insert_stage_data(const char *path,
289 struct tree *o, struct tree *a, struct tree *b,
290 struct path_list *entries)
291 {
292 struct path_list_item *item;
293 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
294 get_tree_entry(o->object.sha1, path,
295 e->stages[1].sha, &e->stages[1].mode);
296 get_tree_entry(a->object.sha1, path,
297 e->stages[2].sha, &e->stages[2].mode);
298 get_tree_entry(b->object.sha1, path,
299 e->stages[3].sha, &e->stages[3].mode);
300 item = path_list_insert(path, entries);
301 item->util = e;
302 return e;
303 }
304
305 /*
306 * Create a dictionary mapping file names to stage_data objects. The
307 * dictionary contains one entry for every path with a non-zero stage entry.
308 */
309 static struct path_list *get_unmerged(void)
310 {
311 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
312 int i;
313
314 unmerged->strdup_paths = 1;
315
316 for (i = 0; i < active_nr; i++) {
317 struct path_list_item *item;
318 struct stage_data *e;
319 struct cache_entry *ce = active_cache[i];
320 if (!ce_stage(ce))
321 continue;
322
323 item = path_list_lookup(ce->name, unmerged);
324 if (!item) {
325 item = path_list_insert(ce->name, unmerged);
326 item->util = xcalloc(1, sizeof(struct stage_data));
327 }
328 e = item->util;
329 e->stages[ce_stage(ce)].mode = ce->ce_mode;
330 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
331 }
332
333 return unmerged;
334 }
335
336 struct rename
337 {
338 struct diff_filepair *pair;
339 struct stage_data *src_entry;
340 struct stage_data *dst_entry;
341 unsigned processed:1;
342 };
343
344 /*
345 * Get information of all renames which occurred between 'o_tree' and
346 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
347 * 'b_tree') to be able to associate the correct cache entries with
348 * the rename information. 'tree' is always equal to either a_tree or b_tree.
349 */
350 static struct path_list *get_renames(struct tree *tree,
351 struct tree *o_tree,
352 struct tree *a_tree,
353 struct tree *b_tree,
354 struct path_list *entries)
355 {
356 int i;
357 struct path_list *renames;
358 struct diff_options opts;
359
360 renames = xcalloc(1, sizeof(struct path_list));
361 diff_setup(&opts);
362 DIFF_OPT_SET(&opts, RECURSIVE);
363 opts.detect_rename = DIFF_DETECT_RENAME;
364 opts.rename_limit = rename_limit;
365 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
366 if (diff_setup_done(&opts) < 0)
367 die("diff setup failed");
368 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
369 diffcore_std(&opts);
370 for (i = 0; i < diff_queued_diff.nr; ++i) {
371 struct path_list_item *item;
372 struct rename *re;
373 struct diff_filepair *pair = diff_queued_diff.queue[i];
374 if (pair->status != 'R') {
375 diff_free_filepair(pair);
376 continue;
377 }
378 re = xmalloc(sizeof(*re));
379 re->processed = 0;
380 re->pair = pair;
381 item = path_list_lookup(re->pair->one->path, entries);
382 if (!item)
383 re->src_entry = insert_stage_data(re->pair->one->path,
384 o_tree, a_tree, b_tree, entries);
385 else
386 re->src_entry = item->util;
387
388 item = path_list_lookup(re->pair->two->path, entries);
389 if (!item)
390 re->dst_entry = insert_stage_data(re->pair->two->path,
391 o_tree, a_tree, b_tree, entries);
392 else
393 re->dst_entry = item->util;
394 item = path_list_insert(pair->one->path, renames);
395 item->util = re;
396 }
397 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
398 diff_queued_diff.nr = 0;
399 diff_flush(&opts);
400 return renames;
401 }
402
403 static int update_stages(const char *path, struct diff_filespec *o,
404 struct diff_filespec *a, struct diff_filespec *b,
405 int clear)
406 {
407 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
408 if (clear)
409 if (remove_file_from_cache(path))
410 return -1;
411 if (o)
412 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
413 return -1;
414 if (a)
415 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
416 return -1;
417 if (b)
418 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
419 return -1;
420 return 0;
421 }
422
423 static int remove_path(const char *name)
424 {
425 int ret;
426 char *slash, *dirs;
427
428 ret = unlink(name);
429 if (ret)
430 return ret;
431 dirs = xstrdup(name);
432 while ((slash = strrchr(name, '/'))) {
433 *slash = '\0';
434 if (rmdir(name) != 0)
435 break;
436 }
437 free(dirs);
438 return ret;
439 }
440
441 static int remove_file(int clean, const char *path, int no_wd)
442 {
443 int update_cache = index_only || clean;
444 int update_working_directory = !index_only && !no_wd;
445
446 if (update_cache) {
447 if (remove_file_from_cache(path))
448 return -1;
449 }
450 if (update_working_directory) {
451 unlink(path);
452 if (errno != ENOENT || errno != EISDIR)
453 return -1;
454 remove_path(path);
455 }
456 return 0;
457 }
458
459 static char *unique_path(const char *path, const char *branch)
460 {
461 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
462 int suffix = 0;
463 struct stat st;
464 char *p = newpath + strlen(path);
465 strcpy(newpath, path);
466 *(p++) = '~';
467 strcpy(p, branch);
468 for (; *p; ++p)
469 if ('/' == *p)
470 *p = '_';
471 while (path_list_has_path(&current_file_set, newpath) ||
472 path_list_has_path(&current_directory_set, newpath) ||
473 lstat(newpath, &st) == 0)
474 sprintf(p, "_%d", suffix++);
475
476 path_list_insert(newpath, &current_file_set);
477 return newpath;
478 }
479
480 static int mkdir_p(const char *path, unsigned long mode)
481 {
482 /* path points to cache entries, so xstrdup before messing with it */
483 char *buf = xstrdup(path);
484 int result = safe_create_leading_directories(buf);
485 free(buf);
486 return result;
487 }
488
489 static void flush_buffer(int fd, const char *buf, unsigned long size)
490 {
491 while (size > 0) {
492 long ret = write_in_full(fd, buf, size);
493 if (ret < 0) {
494 /* Ignore epipe */
495 if (errno == EPIPE)
496 break;
497 die("merge-recursive: %s", strerror(errno));
498 } else if (!ret) {
499 die("merge-recursive: disk full?");
500 }
501 size -= ret;
502 buf += ret;
503 }
504 }
505
506 static int make_room_for_path(const char *path)
507 {
508 int status;
509 const char *msg = "failed to create path '%s'%s";
510
511 status = mkdir_p(path, 0777);
512 if (status) {
513 if (status == -3) {
514 /* something else exists */
515 error(msg, path, ": perhaps a D/F conflict?");
516 return -1;
517 }
518 die(msg, path, "");
519 }
520
521 /* Successful unlink is good.. */
522 if (!unlink(path))
523 return 0;
524 /* .. and so is no existing file */
525 if (errno == ENOENT)
526 return 0;
527 /* .. but not some other error (who really cares what?) */
528 return error(msg, path, ": perhaps a D/F conflict?");
529 }
530
531 static void update_file_flags(const unsigned char *sha,
532 unsigned mode,
533 const char *path,
534 int update_cache,
535 int update_wd)
536 {
537 if (index_only)
538 update_wd = 0;
539
540 if (update_wd) {
541 enum object_type type;
542 void *buf;
543 unsigned long size;
544
545 if (S_ISGITLINK(mode))
546 die("cannot read object %s '%s': It is a submodule!",
547 sha1_to_hex(sha), path);
548
549 buf = read_sha1_file(sha, &type, &size);
550 if (!buf)
551 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
552 if (type != OBJ_BLOB)
553 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
554
555 if (make_room_for_path(path) < 0) {
556 update_wd = 0;
557 goto update_index;
558 }
559 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
560 int fd;
561 if (mode & 0100)
562 mode = 0777;
563 else
564 mode = 0666;
565 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
566 if (fd < 0)
567 die("failed to open %s: %s", path, strerror(errno));
568 flush_buffer(fd, buf, size);
569 close(fd);
570 } else if (S_ISLNK(mode)) {
571 char *lnk = xmemdupz(buf, size);
572 mkdir_p(path, 0777);
573 unlink(path);
574 symlink(lnk, path);
575 free(lnk);
576 } else
577 die("do not know what to do with %06o %s '%s'",
578 mode, sha1_to_hex(sha), path);
579 }
580 update_index:
581 if (update_cache)
582 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
583 }
584
585 static void update_file(int clean,
586 const unsigned char *sha,
587 unsigned mode,
588 const char *path)
589 {
590 update_file_flags(sha, mode, path, index_only || clean, !index_only);
591 }
592
593 /* Low level file merging, update and removal */
594
595 struct merge_file_info
596 {
597 unsigned char sha[20];
598 unsigned mode;
599 unsigned clean:1,
600 merge:1;
601 };
602
603 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
604 {
605 unsigned long size;
606 enum object_type type;
607
608 if (!hashcmp(sha1, null_sha1)) {
609 mm->ptr = xstrdup("");
610 mm->size = 0;
611 return;
612 }
613
614 mm->ptr = read_sha1_file(sha1, &type, &size);
615 if (!mm->ptr || type != OBJ_BLOB)
616 die("unable to read blob object %s", sha1_to_hex(sha1));
617 mm->size = size;
618 }
619
620 /*
621 * Customizable low-level merge drivers support.
622 */
623
624 struct ll_merge_driver;
625 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
626 const char *path,
627 mmfile_t *orig,
628 mmfile_t *src1, const char *name1,
629 mmfile_t *src2, const char *name2,
630 mmbuffer_t *result);
631
632 struct ll_merge_driver {
633 const char *name;
634 const char *description;
635 ll_merge_fn fn;
636 const char *recursive;
637 struct ll_merge_driver *next;
638 char *cmdline;
639 };
640
641 /*
642 * Built-in low-levels
643 */
644 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
645 const char *path_unused,
646 mmfile_t *orig,
647 mmfile_t *src1, const char *name1,
648 mmfile_t *src2, const char *name2,
649 mmbuffer_t *result)
650 {
651 /*
652 * The tentative merge result is "ours" for the final round,
653 * or common ancestor for an internal merge. Still return
654 * "conflicted merge" status.
655 */
656 mmfile_t *stolen = index_only ? orig : src1;
657
658 result->ptr = stolen->ptr;
659 result->size = stolen->size;
660 stolen->ptr = NULL;
661 return 1;
662 }
663
664 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
665 const char *path_unused,
666 mmfile_t *orig,
667 mmfile_t *src1, const char *name1,
668 mmfile_t *src2, const char *name2,
669 mmbuffer_t *result)
670 {
671 xpparam_t xpp;
672
673 if (buffer_is_binary(orig->ptr, orig->size) ||
674 buffer_is_binary(src1->ptr, src1->size) ||
675 buffer_is_binary(src2->ptr, src2->size)) {
676 warning("Cannot merge binary files: %s vs. %s\n",
677 name1, name2);
678 return ll_binary_merge(drv_unused, path_unused,
679 orig, src1, name1,
680 src2, name2,
681 result);
682 }
683
684 memset(&xpp, 0, sizeof(xpp));
685 return xdl_merge(orig,
686 src1, name1,
687 src2, name2,
688 &xpp, XDL_MERGE_ZEALOUS,
689 result);
690 }
691
692 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
693 const char *path_unused,
694 mmfile_t *orig,
695 mmfile_t *src1, const char *name1,
696 mmfile_t *src2, const char *name2,
697 mmbuffer_t *result)
698 {
699 char *src, *dst;
700 long size;
701 const int marker_size = 7;
702
703 int status = ll_xdl_merge(drv_unused, path_unused,
704 orig, src1, NULL, src2, NULL, result);
705 if (status <= 0)
706 return status;
707 size = result->size;
708 src = dst = result->ptr;
709 while (size) {
710 char ch;
711 if ((marker_size < size) &&
712 (*src == '<' || *src == '=' || *src == '>')) {
713 int i;
714 ch = *src;
715 for (i = 0; i < marker_size; i++)
716 if (src[i] != ch)
717 goto not_a_marker;
718 if (src[marker_size] != '\n')
719 goto not_a_marker;
720 src += marker_size + 1;
721 size -= marker_size + 1;
722 continue;
723 }
724 not_a_marker:
725 do {
726 ch = *src++;
727 *dst++ = ch;
728 size--;
729 } while (ch != '\n' && size);
730 }
731 result->size = dst - result->ptr;
732 return 0;
733 }
734
735 #define LL_BINARY_MERGE 0
736 #define LL_TEXT_MERGE 1
737 #define LL_UNION_MERGE 2
738 static struct ll_merge_driver ll_merge_drv[] = {
739 { "binary", "built-in binary merge", ll_binary_merge },
740 { "text", "built-in 3-way text merge", ll_xdl_merge },
741 { "union", "built-in union merge", ll_union_merge },
742 };
743
744 static void create_temp(mmfile_t *src, char *path)
745 {
746 int fd;
747
748 strcpy(path, ".merge_file_XXXXXX");
749 fd = xmkstemp(path);
750 if (write_in_full(fd, src->ptr, src->size) != src->size)
751 die("unable to write temp-file");
752 close(fd);
753 }
754
755 /*
756 * User defined low-level merge driver support.
757 */
758 static int ll_ext_merge(const struct ll_merge_driver *fn,
759 const char *path,
760 mmfile_t *orig,
761 mmfile_t *src1, const char *name1,
762 mmfile_t *src2, const char *name2,
763 mmbuffer_t *result)
764 {
765 char temp[3][50];
766 char cmdbuf[2048];
767 struct interp table[] = {
768 { "%O" },
769 { "%A" },
770 { "%B" },
771 };
772 struct child_process child;
773 const char *args[20];
774 int status, fd, i;
775 struct stat st;
776
777 if (fn->cmdline == NULL)
778 die("custom merge driver %s lacks command line.", fn->name);
779
780 result->ptr = NULL;
781 result->size = 0;
782 create_temp(orig, temp[0]);
783 create_temp(src1, temp[1]);
784 create_temp(src2, temp[2]);
785
786 interp_set_entry(table, 0, temp[0]);
787 interp_set_entry(table, 1, temp[1]);
788 interp_set_entry(table, 2, temp[2]);
789
790 output(1, "merging %s using %s", path,
791 fn->description ? fn->description : fn->name);
792
793 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
794
795 memset(&child, 0, sizeof(child));
796 child.argv = args;
797 args[0] = "sh";
798 args[1] = "-c";
799 args[2] = cmdbuf;
800 args[3] = NULL;
801
802 status = run_command(&child);
803 if (status < -ERR_RUN_COMMAND_FORK)
804 ; /* failure in run-command */
805 else
806 status = -status;
807 fd = open(temp[1], O_RDONLY);
808 if (fd < 0)
809 goto bad;
810 if (fstat(fd, &st))
811 goto close_bad;
812 result->size = st.st_size;
813 result->ptr = xmalloc(result->size + 1);
814 if (read_in_full(fd, result->ptr, result->size) != result->size) {
815 free(result->ptr);
816 result->ptr = NULL;
817 result->size = 0;
818 }
819 close_bad:
820 close(fd);
821 bad:
822 for (i = 0; i < 3; i++)
823 unlink(temp[i]);
824 return status;
825 }
826
827 /*
828 * merge.default and merge.driver configuration items
829 */
830 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
831 static const char *default_ll_merge;
832
833 static int read_merge_config(const char *var, const char *value)
834 {
835 struct ll_merge_driver *fn;
836 const char *ep, *name;
837 int namelen;
838
839 if (!strcmp(var, "merge.default")) {
840 if (!value)
841 return config_error_nonbool(var);
842 default_ll_merge = strdup(value);
843 return 0;
844 }
845
846 /*
847 * We are not interested in anything but "merge.<name>.variable";
848 * especially, we do not want to look at variables such as
849 * "merge.summary", "merge.tool", and "merge.verbosity".
850 */
851 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
852 return 0;
853
854 /*
855 * Find existing one as we might be processing merge.<name>.var2
856 * after seeing merge.<name>.var1.
857 */
858 name = var + 6;
859 namelen = ep - name;
860 for (fn = ll_user_merge; fn; fn = fn->next)
861 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
862 break;
863 if (!fn) {
864 fn = xcalloc(1, sizeof(struct ll_merge_driver));
865 fn->name = xmemdupz(name, namelen);
866 fn->fn = ll_ext_merge;
867 *ll_user_merge_tail = fn;
868 ll_user_merge_tail = &(fn->next);
869 }
870
871 ep++;
872
873 if (!strcmp("name", ep)) {
874 if (!value)
875 return config_error_nonbool(var);
876 fn->description = strdup(value);
877 return 0;
878 }
879
880 if (!strcmp("driver", ep)) {
881 if (!value)
882 return config_error_nonbool(var);
883 /*
884 * merge.<name>.driver specifies the command line:
885 *
886 * command-line
887 *
888 * The command-line will be interpolated with the following
889 * tokens and is given to the shell:
890 *
891 * %O - temporary file name for the merge base.
892 * %A - temporary file name for our version.
893 * %B - temporary file name for the other branches' version.
894 *
895 * The external merge driver should write the results in the
896 * file named by %A, and signal that it has done with zero exit
897 * status.
898 */
899 fn->cmdline = strdup(value);
900 return 0;
901 }
902
903 if (!strcmp("recursive", ep)) {
904 if (!value)
905 return config_error_nonbool(var);
906 fn->recursive = strdup(value);
907 return 0;
908 }
909
910 return 0;
911 }
912
913 static void initialize_ll_merge(void)
914 {
915 if (ll_user_merge_tail)
916 return;
917 ll_user_merge_tail = &ll_user_merge;
918 git_config(read_merge_config);
919 }
920
921 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
922 {
923 struct ll_merge_driver *fn;
924 const char *name;
925 int i;
926
927 initialize_ll_merge();
928
929 if (ATTR_TRUE(merge_attr))
930 return &ll_merge_drv[LL_TEXT_MERGE];
931 else if (ATTR_FALSE(merge_attr))
932 return &ll_merge_drv[LL_BINARY_MERGE];
933 else if (ATTR_UNSET(merge_attr)) {
934 if (!default_ll_merge)
935 return &ll_merge_drv[LL_TEXT_MERGE];
936 else
937 name = default_ll_merge;
938 }
939 else
940 name = merge_attr;
941
942 for (fn = ll_user_merge; fn; fn = fn->next)
943 if (!strcmp(fn->name, name))
944 return fn;
945
946 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
947 if (!strcmp(ll_merge_drv[i].name, name))
948 return &ll_merge_drv[i];
949
950 /* default to the 3-way */
951 return &ll_merge_drv[LL_TEXT_MERGE];
952 }
953
954 static const char *git_path_check_merge(const char *path)
955 {
956 static struct git_attr_check attr_merge_check;
957
958 if (!attr_merge_check.attr)
959 attr_merge_check.attr = git_attr("merge", 5);
960
961 if (git_checkattr(path, 1, &attr_merge_check))
962 return NULL;
963 return attr_merge_check.value;
964 }
965
966 static int ll_merge(mmbuffer_t *result_buf,
967 struct diff_filespec *o,
968 struct diff_filespec *a,
969 struct diff_filespec *b,
970 const char *branch1,
971 const char *branch2)
972 {
973 mmfile_t orig, src1, src2;
974 char *name1, *name2;
975 int merge_status;
976 const char *ll_driver_name;
977 const struct ll_merge_driver *driver;
978
979 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
980 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
981
982 fill_mm(o->sha1, &orig);
983 fill_mm(a->sha1, &src1);
984 fill_mm(b->sha1, &src2);
985
986 ll_driver_name = git_path_check_merge(a->path);
987 driver = find_ll_merge_driver(ll_driver_name);
988
989 if (index_only && driver->recursive)
990 driver = find_ll_merge_driver(driver->recursive);
991 merge_status = driver->fn(driver, a->path,
992 &orig, &src1, name1, &src2, name2,
993 result_buf);
994
995 free(name1);
996 free(name2);
997 free(orig.ptr);
998 free(src1.ptr);
999 free(src2.ptr);
1000 return merge_status;
1001 }
1002
1003 static struct merge_file_info merge_file(struct diff_filespec *o,
1004 struct diff_filespec *a, struct diff_filespec *b,
1005 const char *branch1, const char *branch2)
1006 {
1007 struct merge_file_info result;
1008 result.merge = 0;
1009 result.clean = 1;
1010
1011 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1012 result.clean = 0;
1013 if (S_ISREG(a->mode)) {
1014 result.mode = a->mode;
1015 hashcpy(result.sha, a->sha1);
1016 } else {
1017 result.mode = b->mode;
1018 hashcpy(result.sha, b->sha1);
1019 }
1020 } else {
1021 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1022 result.merge = 1;
1023
1024 result.mode = a->mode == o->mode ? b->mode: a->mode;
1025
1026 if (sha_eq(a->sha1, o->sha1))
1027 hashcpy(result.sha, b->sha1);
1028 else if (sha_eq(b->sha1, o->sha1))
1029 hashcpy(result.sha, a->sha1);
1030 else if (S_ISREG(a->mode)) {
1031 mmbuffer_t result_buf;
1032 int merge_status;
1033
1034 merge_status = ll_merge(&result_buf, o, a, b,
1035 branch1, branch2);
1036
1037 if ((merge_status < 0) || !result_buf.ptr)
1038 die("Failed to execute internal merge");
1039
1040 if (write_sha1_file(result_buf.ptr, result_buf.size,
1041 blob_type, result.sha))
1042 die("Unable to add %s to database",
1043 a->path);
1044
1045 free(result_buf.ptr);
1046 result.clean = (merge_status == 0);
1047 } else if (S_ISGITLINK(a->mode)) {
1048 result.clean = 0;
1049 hashcpy(result.sha, a->sha1);
1050 } else if (S_ISLNK(a->mode)) {
1051 hashcpy(result.sha, a->sha1);
1052
1053 if (!sha_eq(a->sha1, b->sha1))
1054 result.clean = 0;
1055 } else {
1056 die("unsupported object type in the tree");
1057 }
1058 }
1059
1060 return result;
1061 }
1062
1063 static void conflict_rename_rename(struct rename *ren1,
1064 const char *branch1,
1065 struct rename *ren2,
1066 const char *branch2)
1067 {
1068 char *del[2];
1069 int delp = 0;
1070 const char *ren1_dst = ren1->pair->two->path;
1071 const char *ren2_dst = ren2->pair->two->path;
1072 const char *dst_name1 = ren1_dst;
1073 const char *dst_name2 = ren2_dst;
1074 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1075 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1076 output(1, "%s is a directory in %s added as %s instead",
1077 ren1_dst, branch2, dst_name1);
1078 remove_file(0, ren1_dst, 0);
1079 }
1080 if (path_list_has_path(&current_directory_set, ren2_dst)) {
1081 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1082 output(1, "%s is a directory in %s added as %s instead",
1083 ren2_dst, branch1, dst_name2);
1084 remove_file(0, ren2_dst, 0);
1085 }
1086 if (index_only) {
1087 remove_file_from_cache(dst_name1);
1088 remove_file_from_cache(dst_name2);
1089 /*
1090 * Uncomment to leave the conflicting names in the resulting tree
1091 *
1092 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1093 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1094 */
1095 } else {
1096 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1097 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1098 }
1099 while (delp--)
1100 free(del[delp]);
1101 }
1102
1103 static void conflict_rename_dir(struct rename *ren1,
1104 const char *branch1)
1105 {
1106 char *new_path = unique_path(ren1->pair->two->path, branch1);
1107 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1108 remove_file(0, ren1->pair->two->path, 0);
1109 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1110 free(new_path);
1111 }
1112
1113 static void conflict_rename_rename_2(struct rename *ren1,
1114 const char *branch1,
1115 struct rename *ren2,
1116 const char *branch2)
1117 {
1118 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1119 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1120 output(1, "Renamed %s to %s and %s to %s instead",
1121 ren1->pair->one->path, new_path1,
1122 ren2->pair->one->path, new_path2);
1123 remove_file(0, ren1->pair->two->path, 0);
1124 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1125 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1126 free(new_path2);
1127 free(new_path1);
1128 }
1129
1130 static int process_renames(struct path_list *a_renames,
1131 struct path_list *b_renames,
1132 const char *a_branch,
1133 const char *b_branch)
1134 {
1135 int clean_merge = 1, i, j;
1136 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1137 const struct rename *sre;
1138
1139 for (i = 0; i < a_renames->nr; i++) {
1140 sre = a_renames->items[i].util;
1141 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1142 = sre->dst_entry;
1143 }
1144 for (i = 0; i < b_renames->nr; i++) {
1145 sre = b_renames->items[i].util;
1146 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1147 = sre->dst_entry;
1148 }
1149
1150 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1151 int compare;
1152 char *src;
1153 struct path_list *renames1, *renames2, *renames2Dst;
1154 struct rename *ren1 = NULL, *ren2 = NULL;
1155 const char *branch1, *branch2;
1156 const char *ren1_src, *ren1_dst;
1157
1158 if (i >= a_renames->nr) {
1159 compare = 1;
1160 ren2 = b_renames->items[j++].util;
1161 } else if (j >= b_renames->nr) {
1162 compare = -1;
1163 ren1 = a_renames->items[i++].util;
1164 } else {
1165 compare = strcmp(a_renames->items[i].path,
1166 b_renames->items[j].path);
1167 if (compare <= 0)
1168 ren1 = a_renames->items[i++].util;
1169 if (compare >= 0)
1170 ren2 = b_renames->items[j++].util;
1171 }
1172
1173 /* TODO: refactor, so that 1/2 are not needed */
1174 if (ren1) {
1175 renames1 = a_renames;
1176 renames2 = b_renames;
1177 renames2Dst = &b_by_dst;
1178 branch1 = a_branch;
1179 branch2 = b_branch;
1180 } else {
1181 struct rename *tmp;
1182 renames1 = b_renames;
1183 renames2 = a_renames;
1184 renames2Dst = &a_by_dst;
1185 branch1 = b_branch;
1186 branch2 = a_branch;
1187 tmp = ren2;
1188 ren2 = ren1;
1189 ren1 = tmp;
1190 }
1191 src = ren1->pair->one->path;
1192
1193 ren1->dst_entry->processed = 1;
1194 ren1->src_entry->processed = 1;
1195
1196 if (ren1->processed)
1197 continue;
1198 ren1->processed = 1;
1199
1200 ren1_src = ren1->pair->one->path;
1201 ren1_dst = ren1->pair->two->path;
1202
1203 if (ren2) {
1204 const char *ren2_src = ren2->pair->one->path;
1205 const char *ren2_dst = ren2->pair->two->path;
1206 /* Renamed in 1 and renamed in 2 */
1207 if (strcmp(ren1_src, ren2_src) != 0)
1208 die("ren1.src != ren2.src");
1209 ren2->dst_entry->processed = 1;
1210 ren2->processed = 1;
1211 if (strcmp(ren1_dst, ren2_dst) != 0) {
1212 clean_merge = 0;
1213 output(1, "CONFLICT (rename/rename): "
1214 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1215 "rename \"%s\"->\"%s\" in \"%s\"%s",
1216 src, ren1_dst, branch1,
1217 src, ren2_dst, branch2,
1218 index_only ? " (left unresolved)": "");
1219 if (index_only) {
1220 remove_file_from_cache(src);
1221 update_file(0, ren1->pair->one->sha1,
1222 ren1->pair->one->mode, src);
1223 }
1224 conflict_rename_rename(ren1, branch1, ren2, branch2);
1225 } else {
1226 struct merge_file_info mfi;
1227 remove_file(1, ren1_src, 1);
1228 mfi = merge_file(ren1->pair->one,
1229 ren1->pair->two,
1230 ren2->pair->two,
1231 branch1,
1232 branch2);
1233 if (mfi.merge || !mfi.clean)
1234 output(1, "Renamed %s->%s", src, ren1_dst);
1235
1236 if (mfi.merge)
1237 output(2, "Auto-merged %s", ren1_dst);
1238
1239 if (!mfi.clean) {
1240 output(1, "CONFLICT (content): merge conflict in %s",
1241 ren1_dst);
1242 clean_merge = 0;
1243
1244 if (!index_only)
1245 update_stages(ren1_dst,
1246 ren1->pair->one,
1247 ren1->pair->two,
1248 ren2->pair->two,
1249 1 /* clear */);
1250 }
1251 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1252 }
1253 } else {
1254 /* Renamed in 1, maybe changed in 2 */
1255 struct path_list_item *item;
1256 /* we only use sha1 and mode of these */
1257 struct diff_filespec src_other, dst_other;
1258 int try_merge, stage = a_renames == renames1 ? 3: 2;
1259
1260 remove_file(1, ren1_src, index_only || stage == 3);
1261
1262 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1263 src_other.mode = ren1->src_entry->stages[stage].mode;
1264 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1265 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1266
1267 try_merge = 0;
1268
1269 if (path_list_has_path(&current_directory_set, ren1_dst)) {
1270 clean_merge = 0;
1271 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1272 " directory %s added in %s",
1273 ren1_src, ren1_dst, branch1,
1274 ren1_dst, branch2);
1275 conflict_rename_dir(ren1, branch1);
1276 } else if (sha_eq(src_other.sha1, null_sha1)) {
1277 clean_merge = 0;
1278 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1279 "and deleted in %s",
1280 ren1_src, ren1_dst, branch1,
1281 branch2);
1282 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1283 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1284 const char *new_path;
1285 clean_merge = 0;
1286 try_merge = 1;
1287 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1288 "%s added in %s",
1289 ren1_src, ren1_dst, branch1,
1290 ren1_dst, branch2);
1291 new_path = unique_path(ren1_dst, branch2);
1292 output(1, "Added as %s instead", new_path);
1293 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1294 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1295 ren2 = item->util;
1296 clean_merge = 0;
1297 ren2->processed = 1;
1298 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1299 "Renamed %s->%s in %s",
1300 ren1_src, ren1_dst, branch1,
1301 ren2->pair->one->path, ren2->pair->two->path, branch2);
1302 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1303 } else
1304 try_merge = 1;
1305
1306 if (try_merge) {
1307 struct diff_filespec *o, *a, *b;
1308 struct merge_file_info mfi;
1309 src_other.path = (char *)ren1_src;
1310
1311 o = ren1->pair->one;
1312 if (a_renames == renames1) {
1313 a = ren1->pair->two;
1314 b = &src_other;
1315 } else {
1316 b = ren1->pair->two;
1317 a = &src_other;
1318 }
1319 mfi = merge_file(o, a, b,
1320 a_branch, b_branch);
1321
1322 if (mfi.clean &&
1323 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1324 mfi.mode == ren1->pair->two->mode)
1325 /*
1326 * This messaged is part of
1327 * t6022 test. If you change
1328 * it update the test too.
1329 */
1330 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1331 else {
1332 if (mfi.merge || !mfi.clean)
1333 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1334 if (mfi.merge)
1335 output(2, "Auto-merged %s", ren1_dst);
1336 if (!mfi.clean) {
1337 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1338 ren1_dst);
1339 clean_merge = 0;
1340
1341 if (!index_only)
1342 update_stages(ren1_dst,
1343 o, a, b, 1);
1344 }
1345 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1346 }
1347 }
1348 }
1349 }
1350 path_list_clear(&a_by_dst, 0);
1351 path_list_clear(&b_by_dst, 0);
1352
1353 return clean_merge;
1354 }
1355
1356 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1357 {
1358 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1359 }
1360
1361 /* Per entry merge function */
1362 static int process_entry(const char *path, struct stage_data *entry,
1363 const char *branch1,
1364 const char *branch2)
1365 {
1366 /*
1367 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1368 print_index_entry("\tpath: ", entry);
1369 */
1370 int clean_merge = 1;
1371 unsigned o_mode = entry->stages[1].mode;
1372 unsigned a_mode = entry->stages[2].mode;
1373 unsigned b_mode = entry->stages[3].mode;
1374 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1375 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1376 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1377
1378 if (o_sha && (!a_sha || !b_sha)) {
1379 /* Case A: Deleted in one */
1380 if ((!a_sha && !b_sha) ||
1381 (sha_eq(a_sha, o_sha) && !b_sha) ||
1382 (!a_sha && sha_eq(b_sha, o_sha))) {
1383 /* Deleted in both or deleted in one and
1384 * unchanged in the other */
1385 if (a_sha)
1386 output(2, "Removed %s", path);
1387 /* do not touch working file if it did not exist */
1388 remove_file(1, path, !a_sha);
1389 } else {
1390 /* Deleted in one and changed in the other */
1391 clean_merge = 0;
1392 if (!a_sha) {
1393 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1394 "and modified in %s. Version %s of %s left in tree.",
1395 path, branch1,
1396 branch2, branch2, path);
1397 update_file(0, b_sha, b_mode, path);
1398 } else {
1399 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1400 "and modified in %s. Version %s of %s left in tree.",
1401 path, branch2,
1402 branch1, branch1, path);
1403 update_file(0, a_sha, a_mode, path);
1404 }
1405 }
1406
1407 } else if ((!o_sha && a_sha && !b_sha) ||
1408 (!o_sha && !a_sha && b_sha)) {
1409 /* Case B: Added in one. */
1410 const char *add_branch;
1411 const char *other_branch;
1412 unsigned mode;
1413 const unsigned char *sha;
1414 const char *conf;
1415
1416 if (a_sha) {
1417 add_branch = branch1;
1418 other_branch = branch2;
1419 mode = a_mode;
1420 sha = a_sha;
1421 conf = "file/directory";
1422 } else {
1423 add_branch = branch2;
1424 other_branch = branch1;
1425 mode = b_mode;
1426 sha = b_sha;
1427 conf = "directory/file";
1428 }
1429 if (path_list_has_path(&current_directory_set, path)) {
1430 const char *new_path = unique_path(path, add_branch);
1431 clean_merge = 0;
1432 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1433 "Added %s as %s",
1434 conf, path, other_branch, path, new_path);
1435 remove_file(0, path, 0);
1436 update_file(0, sha, mode, new_path);
1437 } else {
1438 output(2, "Added %s", path);
1439 update_file(1, sha, mode, path);
1440 }
1441 } else if (a_sha && b_sha) {
1442 /* Case C: Added in both (check for same permissions) and */
1443 /* case D: Modified in both, but differently. */
1444 const char *reason = "content";
1445 struct merge_file_info mfi;
1446 struct diff_filespec o, a, b;
1447
1448 if (!o_sha) {
1449 reason = "add/add";
1450 o_sha = (unsigned char *)null_sha1;
1451 }
1452 output(2, "Auto-merged %s", path);
1453 o.path = a.path = b.path = (char *)path;
1454 hashcpy(o.sha1, o_sha);
1455 o.mode = o_mode;
1456 hashcpy(a.sha1, a_sha);
1457 a.mode = a_mode;
1458 hashcpy(b.sha1, b_sha);
1459 b.mode = b_mode;
1460
1461 mfi = merge_file(&o, &a, &b,
1462 branch1, branch2);
1463
1464 clean_merge = mfi.clean;
1465 if (mfi.clean)
1466 update_file(1, mfi.sha, mfi.mode, path);
1467 else if (S_ISGITLINK(mfi.mode))
1468 output(1, "CONFLICT (submodule): Merge conflict in %s "
1469 "- needs %s", path, sha1_to_hex(b.sha1));
1470 else {
1471 output(1, "CONFLICT (%s): Merge conflict in %s",
1472 reason, path);
1473
1474 if (index_only)
1475 update_file(0, mfi.sha, mfi.mode, path);
1476 else
1477 update_file_flags(mfi.sha, mfi.mode, path,
1478 0 /* update_cache */, 1 /* update_working_directory */);
1479 }
1480 } else if (!o_sha && !a_sha && !b_sha) {
1481 /*
1482 * this entry was deleted altogether. a_mode == 0 means
1483 * we had that path and want to actively remove it.
1484 */
1485 remove_file(1, path, !a_mode);
1486 } else
1487 die("Fatal merge failure, shouldn't happen.");
1488
1489 return clean_merge;
1490 }
1491
1492 int merge_trees(struct tree *head,
1493 struct tree *merge,
1494 struct tree *common,
1495 const char *branch1,
1496 const char *branch2,
1497 struct tree **result)
1498 {
1499 int code, clean;
1500
1501 if (subtree_merge) {
1502 merge = shift_tree_object(head, merge);
1503 common = shift_tree_object(head, common);
1504 }
1505
1506 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1507 output(0, "Already uptodate!");
1508 *result = head;
1509 return 1;
1510 }
1511
1512 code = git_merge_trees(index_only, common, head, merge);
1513
1514 if (code != 0)
1515 die("merging of trees %s and %s failed",
1516 sha1_to_hex(head->object.sha1),
1517 sha1_to_hex(merge->object.sha1));
1518
1519 if (unmerged_cache()) {
1520 struct path_list *entries, *re_head, *re_merge;
1521 int i;
1522 path_list_clear(&current_file_set, 1);
1523 path_list_clear(&current_directory_set, 1);
1524 get_files_dirs(head);
1525 get_files_dirs(merge);
1526
1527 entries = get_unmerged();
1528 re_head = get_renames(head, common, head, merge, entries);
1529 re_merge = get_renames(merge, common, head, merge, entries);
1530 clean = process_renames(re_head, re_merge,
1531 branch1, branch2);
1532 for (i = 0; i < entries->nr; i++) {
1533 const char *path = entries->items[i].path;
1534 struct stage_data *e = entries->items[i].util;
1535 if (!e->processed
1536 && !process_entry(path, e, branch1, branch2))
1537 clean = 0;
1538 }
1539
1540 path_list_clear(re_merge, 0);
1541 path_list_clear(re_head, 0);
1542 path_list_clear(entries, 1);
1543
1544 }
1545 else
1546 clean = 1;
1547
1548 if (index_only)
1549 *result = write_tree_from_memory();
1550
1551 return clean;
1552 }
1553
1554 static struct commit_list *reverse_commit_list(struct commit_list *list)
1555 {
1556 struct commit_list *next = NULL, *current, *backup;
1557 for (current = list; current; current = backup) {
1558 backup = current->next;
1559 current->next = next;
1560 next = current;
1561 }
1562 return next;
1563 }
1564
1565 /*
1566 * Merge the commits h1 and h2, return the resulting virtual
1567 * commit object and a flag indicating the cleanness of the merge.
1568 */
1569 int merge_recursive(struct commit *h1,
1570 struct commit *h2,
1571 const char *branch1,
1572 const char *branch2,
1573 struct commit_list *ca,
1574 struct commit **result)
1575 {
1576 struct commit_list *iter;
1577 struct commit *merged_common_ancestors;
1578 struct tree *mrtree = mrtree;
1579 int clean;
1580
1581 if (show(4)) {
1582 output(4, "Merging:");
1583 output_commit_title(h1);
1584 output_commit_title(h2);
1585 }
1586
1587 if (!ca) {
1588 ca = get_merge_bases(h1, h2, 1);
1589 ca = reverse_commit_list(ca);
1590 }
1591
1592 if (show(5)) {
1593 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1594 for (iter = ca; iter; iter = iter->next)
1595 output_commit_title(iter->item);
1596 }
1597
1598 merged_common_ancestors = pop_commit(&ca);
1599 if (merged_common_ancestors == NULL) {
1600 /* if there is no common ancestor, make an empty tree */
1601 struct tree *tree = xcalloc(1, sizeof(struct tree));
1602
1603 tree->object.parsed = 1;
1604 tree->object.type = OBJ_TREE;
1605 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1606 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1607 }
1608
1609 for (iter = ca; iter; iter = iter->next) {
1610 call_depth++;
1611 /*
1612 * When the merge fails, the result contains files
1613 * with conflict markers. The cleanness flag is
1614 * ignored, it was never actually used, as result of
1615 * merge_trees has always overwritten it: the committed
1616 * "conflicts" were already resolved.
1617 */
1618 discard_cache();
1619 merge_recursive(merged_common_ancestors, iter->item,
1620 "Temporary merge branch 1",
1621 "Temporary merge branch 2",
1622 NULL,
1623 &merged_common_ancestors);
1624 call_depth--;
1625
1626 if (!merged_common_ancestors)
1627 die("merge returned no commit");
1628 }
1629
1630 discard_cache();
1631 if (!call_depth) {
1632 read_cache();
1633 index_only = 0;
1634 } else
1635 index_only = 1;
1636
1637 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1638 branch1, branch2, &mrtree);
1639
1640 if (index_only) {
1641 *result = make_virtual_commit(mrtree, "merged tree");
1642 commit_list_insert(h1, &(*result)->parents);
1643 commit_list_insert(h2, &(*result)->parents->next);
1644 }
1645 flush_output();
1646 return clean;
1647 }
1648
1649 static const char *better_branch_name(const char *branch)
1650 {
1651 static char githead_env[8 + 40 + 1];
1652 char *name;
1653
1654 if (strlen(branch) != 40)
1655 return branch;
1656 sprintf(githead_env, "GITHEAD_%s", branch);
1657 name = getenv(githead_env);
1658 return name ? name : branch;
1659 }
1660
1661 static struct commit *get_ref(const char *ref)
1662 {
1663 unsigned char sha1[20];
1664 struct object *object;
1665
1666 if (get_sha1(ref, sha1))
1667 die("Could not resolve ref '%s'", ref);
1668 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1669 if (!object)
1670 return NULL;
1671 if (object->type == OBJ_TREE)
1672 return make_virtual_commit((struct tree*)object,
1673 better_branch_name(ref));
1674 if (object->type != OBJ_COMMIT)
1675 return NULL;
1676 if (parse_commit((struct commit *)object))
1677 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1678 return (struct commit *)object;
1679 }
1680
1681 static int merge_config(const char *var, const char *value)
1682 {
1683 if (!strcasecmp(var, "merge.verbosity")) {
1684 verbosity = git_config_int(var, value);
1685 return 0;
1686 }
1687 if (!strcasecmp(var, "diff.renamelimit")) {
1688 rename_limit = git_config_int(var, value);
1689 return 0;
1690 }
1691 return git_default_config(var, value);
1692 }
1693
1694 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1695 {
1696 static const char *bases[20];
1697 static unsigned bases_count = 0;
1698 int i, clean;
1699 const char *branch1, *branch2;
1700 struct commit *result, *h1, *h2;
1701 struct commit_list *ca = NULL;
1702 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1703 int index_fd;
1704
1705 if (argv[0]) {
1706 int namelen = strlen(argv[0]);
1707 if (8 < namelen &&
1708 !strcmp(argv[0] + namelen - 8, "-subtree"))
1709 subtree_merge = 1;
1710 }
1711
1712 git_config(merge_config);
1713 if (getenv("GIT_MERGE_VERBOSITY"))
1714 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1715
1716 if (argc < 4)
1717 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1718
1719 for (i = 1; i < argc; ++i) {
1720 if (!strcmp(argv[i], "--"))
1721 break;
1722 if (bases_count < sizeof(bases)/sizeof(*bases))
1723 bases[bases_count++] = argv[i];
1724 }
1725 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1726 die("Not handling anything other than two heads merge.");
1727 if (verbosity >= 5)
1728 buffer_output = 0;
1729
1730 branch1 = argv[++i];
1731 branch2 = argv[++i];
1732
1733 h1 = get_ref(branch1);
1734 h2 = get_ref(branch2);
1735
1736 branch1 = better_branch_name(branch1);
1737 branch2 = better_branch_name(branch2);
1738
1739 if (show(3))
1740 printf("Merging %s with %s\n", branch1, branch2);
1741
1742 index_fd = hold_locked_index(lock, 1);
1743
1744 for (i = 0; i < bases_count; i++) {
1745 struct commit *ancestor = get_ref(bases[i]);
1746 ca = commit_list_insert(ancestor, &ca);
1747 }
1748 clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1749
1750 if (active_cache_changed &&
1751 (write_cache(index_fd, active_cache, active_nr) ||
1752 commit_locked_index(lock)))
1753 die ("unable to write %s", get_index_file());
1754
1755 return clean ? 0: 1;
1756 }