merge: convert empty tree constant to the_hash_algo
[git/git.git] / merge.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "diffcore.h"
4 #include "lockfile.h"
5 #include "commit.h"
6 #include "run-command.h"
7 #include "resolve-undo.h"
8 #include "tree-walk.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11
12 static const char *merge_argument(struct commit *commit)
13 {
14 return oid_to_hex(commit ? &commit->object.oid : the_hash_algo->empty_tree);
15 }
16
17 int index_has_changes(struct strbuf *sb)
18 {
19 struct object_id head;
20 int i;
21
22 if (!get_oid_tree("HEAD", &head)) {
23 struct diff_options opt;
24
25 diff_setup(&opt);
26 opt.flags.exit_with_status = 1;
27 if (!sb)
28 opt.flags.quick = 1;
29 do_diff_cache(&head, &opt);
30 diffcore_std(&opt);
31 for (i = 0; sb && i < diff_queued_diff.nr; i++) {
32 if (i)
33 strbuf_addch(sb, ' ');
34 strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
35 }
36 diff_flush(&opt);
37 return opt.flags.has_changes != 0;
38 } else {
39 for (i = 0; sb && i < active_nr; i++) {
40 if (i)
41 strbuf_addch(sb, ' ');
42 strbuf_addstr(sb, active_cache[i]->name);
43 }
44 return !!active_nr;
45 }
46 }
47
48 int try_merge_command(const char *strategy, size_t xopts_nr,
49 const char **xopts, struct commit_list *common,
50 const char *head_arg, struct commit_list *remotes)
51 {
52 struct argv_array args = ARGV_ARRAY_INIT;
53 int i, ret;
54 struct commit_list *j;
55
56 argv_array_pushf(&args, "merge-%s", strategy);
57 for (i = 0; i < xopts_nr; i++)
58 argv_array_pushf(&args, "--%s", xopts[i]);
59 for (j = common; j; j = j->next)
60 argv_array_push(&args, merge_argument(j->item));
61 argv_array_push(&args, "--");
62 argv_array_push(&args, head_arg);
63 for (j = remotes; j; j = j->next)
64 argv_array_push(&args, merge_argument(j->item));
65
66 ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
67 argv_array_clear(&args);
68
69 discard_cache();
70 if (read_cache() < 0)
71 die(_("failed to read the cache"));
72 resolve_undo_clear();
73
74 return ret;
75 }
76
77 int checkout_fast_forward(const struct object_id *head,
78 const struct object_id *remote,
79 int overwrite_ignore)
80 {
81 struct tree *trees[MAX_UNPACK_TREES];
82 struct unpack_trees_options opts;
83 struct tree_desc t[MAX_UNPACK_TREES];
84 int i, nr_trees = 0;
85 struct dir_struct dir;
86 struct lock_file lock_file = LOCK_INIT;
87
88 refresh_cache(REFRESH_QUIET);
89
90 if (hold_locked_index(&lock_file, LOCK_REPORT_ON_ERROR) < 0)
91 return -1;
92
93 memset(&trees, 0, sizeof(trees));
94 memset(&opts, 0, sizeof(opts));
95 memset(&t, 0, sizeof(t));
96 if (overwrite_ignore) {
97 memset(&dir, 0, sizeof(dir));
98 dir.flags |= DIR_SHOW_IGNORED;
99 setup_standard_excludes(&dir);
100 opts.dir = &dir;
101 }
102
103 opts.head_idx = 1;
104 opts.src_index = &the_index;
105 opts.dst_index = &the_index;
106 opts.update = 1;
107 opts.verbose_update = 1;
108 opts.merge = 1;
109 opts.fn = twoway_merge;
110 setup_unpack_trees_porcelain(&opts, "merge");
111
112 trees[nr_trees] = parse_tree_indirect(head);
113 if (!trees[nr_trees++]) {
114 rollback_lock_file(&lock_file);
115 return -1;
116 }
117 trees[nr_trees] = parse_tree_indirect(remote);
118 if (!trees[nr_trees++]) {
119 rollback_lock_file(&lock_file);
120 return -1;
121 }
122 for (i = 0; i < nr_trees; i++) {
123 parse_tree(trees[i]);
124 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
125 }
126 if (unpack_trees(nr_trees, t, &opts)) {
127 rollback_lock_file(&lock_file);
128 return -1;
129 }
130 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
131 return error(_("unable to write new index file"));
132 return 0;
133 }