Merge branch 'jc/maint-1.6.0-read-tree-overlay'
[git] / branch.c
1 #include "cache.h"
2 #include "branch.h"
3 #include "refs.h"
4 #include "remote.h"
5 #include "commit.h"
6
7 struct tracking {
8         struct refspec spec;
9         char *src;
10         const char *remote;
11         int matches;
12 };
13
14 static int find_tracked_branch(struct remote *remote, void *priv)
15 {
16         struct tracking *tracking = priv;
17
18         if (!remote_find_tracking(remote, &tracking->spec)) {
19                 if (++tracking->matches == 1) {
20                         tracking->src = tracking->spec.src;
21                         tracking->remote = remote->name;
22                 } else {
23                         free(tracking->spec.src);
24                         if (tracking->src) {
25                                 free(tracking->src);
26                                 tracking->src = NULL;
27                         }
28                 }
29                 tracking->spec.src = NULL;
30         }
31
32         return 0;
33 }
34
35 static int should_setup_rebase(const struct tracking *tracking)
36 {
37         switch (autorebase) {
38         case AUTOREBASE_NEVER:
39                 return 0;
40         case AUTOREBASE_LOCAL:
41                 return tracking->remote == NULL;
42         case AUTOREBASE_REMOTE:
43                 return tracking->remote != NULL;
44         case AUTOREBASE_ALWAYS:
45                 return 1;
46         }
47         return 0;
48 }
49
50 /*
51  * This is called when new_ref is branched off of orig_ref, and tries
52  * to infer the settings for branch.<new_ref>.{remote,merge} from the
53  * config.
54  */
55 static int setup_tracking(const char *new_ref, const char *orig_ref,
56                           enum branch_track track)
57 {
58         char key[1024];
59         struct tracking tracking;
60
61         if (strlen(new_ref) > 1024 - 7 - 7 - 1)
62                 return error("Tracking not set up: name too long: %s",
63                                 new_ref);
64
65         memset(&tracking, 0, sizeof(tracking));
66         tracking.spec.dst = (char *)orig_ref;
67         if (for_each_remote(find_tracked_branch, &tracking))
68                 return 1;
69
70         if (!tracking.matches)
71                 switch (track) {
72                 case BRANCH_TRACK_ALWAYS:
73                 case BRANCH_TRACK_EXPLICIT:
74                         break;
75                 default:
76                         return 1;
77                 }
78
79         if (tracking.matches > 1)
80                 return error("Not tracking: ambiguous information for ref %s",
81                                 orig_ref);
82
83         sprintf(key, "branch.%s.remote", new_ref);
84         git_config_set(key, tracking.remote ?  tracking.remote : ".");
85         sprintf(key, "branch.%s.merge", new_ref);
86         git_config_set(key, tracking.src ? tracking.src : orig_ref);
87         printf("Branch %s set up to track %s branch %s.\n", new_ref,
88                 tracking.remote ? "remote" : "local", orig_ref);
89         if (should_setup_rebase(&tracking)) {
90                 sprintf(key, "branch.%s.rebase", new_ref);
91                 git_config_set(key, "true");
92                 printf("This branch will rebase on pull.\n");
93         }
94         free(tracking.src);
95
96         return 0;
97 }
98
99 void create_branch(const char *head,
100                    const char *name, const char *start_name,
101                    int force, int reflog, enum branch_track track)
102 {
103         struct ref_lock *lock;
104         struct commit *commit;
105         unsigned char sha1[20];
106         char *real_ref, msg[PATH_MAX + 20];
107         struct strbuf ref = STRBUF_INIT;
108         int forcing = 0;
109         int len;
110
111         len = strlen(name);
112         if (interpret_nth_last_branch(name, &ref) != len) {
113                 strbuf_reset(&ref);
114                 strbuf_add(&ref, name, len);
115         }
116         strbuf_splice(&ref, 0, 0, "refs/heads/", 11);
117
118         if (check_ref_format(ref.buf))
119                 die("'%s' is not a valid branch name.", name);
120
121         if (resolve_ref(ref.buf, sha1, 1, NULL)) {
122                 if (!force)
123                         die("A branch named '%s' already exists.", name);
124                 else if (!is_bare_repository() && !strcmp(head, name))
125                         die("Cannot force update the current branch.");
126                 forcing = 1;
127         }
128
129         real_ref = NULL;
130         if (get_sha1(start_name, sha1))
131                 die("Not a valid object name: '%s'.", start_name);
132
133         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
134         case 0:
135                 /* Not branching from any existing branch */
136                 if (track == BRANCH_TRACK_EXPLICIT)
137                         die("Cannot setup tracking information; starting point is not a branch.");
138                 break;
139         case 1:
140                 /* Unique completion -- good, only if it is a real ref */
141                 if (track == BRANCH_TRACK_EXPLICIT && !strcmp(real_ref, "HEAD"))
142                         die("Cannot setup tracking information; starting point is not a branch.");
143                 break;
144         default:
145                 die("Ambiguous object name: '%s'.", start_name);
146                 break;
147         }
148
149         if ((commit = lookup_commit_reference(sha1)) == NULL)
150                 die("Not a valid branch point: '%s'.", start_name);
151         hashcpy(sha1, commit->object.sha1);
152
153         lock = lock_any_ref_for_update(ref.buf, NULL, 0);
154         if (!lock)
155                 die("Failed to lock ref for update: %s.", strerror(errno));
156
157         if (reflog)
158                 log_all_ref_updates = 1;
159
160         if (forcing)
161                 snprintf(msg, sizeof msg, "branch: Reset from %s",
162                          start_name);
163         else
164                 snprintf(msg, sizeof msg, "branch: Created from %s",
165                          start_name);
166
167         if (real_ref && track)
168                 setup_tracking(name, real_ref, track);
169
170         if (write_ref_sha1(lock, sha1, msg) < 0)
171                 die("Failed to write ref: %s.", strerror(errno));
172
173         strbuf_release(&ref);
174         free(real_ref);
175 }
176
177 void remove_branch_state(void)
178 {
179         unlink(git_path("MERGE_HEAD"));
180         unlink(git_path("MERGE_RR"));
181         unlink(git_path("MERGE_MSG"));
182         unlink(git_path("MERGE_MODE"));
183         unlink(git_path("SQUASH_MSG"));
184 }