Merge branch 'bk/ancestry-path' into jc/branch-desc
[git/git.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 char *origin)
36 {
37 switch (autorebase) {
38 case AUTOREBASE_NEVER:
39 return 0;
40 case AUTOREBASE_LOCAL:
41 return origin == NULL;
42 case AUTOREBASE_REMOTE:
43 return origin != NULL;
44 case AUTOREBASE_ALWAYS:
45 return 1;
46 }
47 return 0;
48 }
49
50 void install_branch_config(int flag, const char *local, const char *origin, const char *remote)
51 {
52 const char *shortname = remote + 11;
53 int remote_is_branch = !prefixcmp(remote, "refs/heads/");
54 struct strbuf key = STRBUF_INIT;
55 int rebasing = should_setup_rebase(origin);
56
57 if (remote_is_branch
58 && !strcmp(local, shortname)
59 && !origin) {
60 warning("Not setting branch %s as its own upstream.",
61 local);
62 return;
63 }
64
65 strbuf_addf(&key, "branch.%s.remote", local);
66 git_config_set(key.buf, origin ? origin : ".");
67
68 strbuf_reset(&key);
69 strbuf_addf(&key, "branch.%s.merge", local);
70 git_config_set(key.buf, remote);
71
72 if (rebasing) {
73 strbuf_reset(&key);
74 strbuf_addf(&key, "branch.%s.rebase", local);
75 git_config_set(key.buf, "true");
76 }
77
78 if (flag & BRANCH_CONFIG_VERBOSE) {
79 strbuf_reset(&key);
80
81 strbuf_addstr(&key, origin ? "remote" : "local");
82
83 /* Are we tracking a proper "branch"? */
84 if (remote_is_branch) {
85 strbuf_addf(&key, " branch %s", shortname);
86 if (origin)
87 strbuf_addf(&key, " from %s", origin);
88 }
89 else
90 strbuf_addf(&key, " ref %s", remote);
91 printf("Branch %s set up to track %s%s.\n",
92 local, key.buf,
93 rebasing ? " by rebasing" : "");
94 }
95 strbuf_release(&key);
96 }
97
98 /*
99 * This is called when new_ref is branched off of orig_ref, and tries
100 * to infer the settings for branch.<new_ref>.{remote,merge} from the
101 * config.
102 */
103 static int setup_tracking(const char *new_ref, const char *orig_ref,
104 enum branch_track track)
105 {
106 struct tracking tracking;
107
108 if (strlen(new_ref) > 1024 - 7 - 7 - 1)
109 return error("Tracking not set up: name too long: %s",
110 new_ref);
111
112 memset(&tracking, 0, sizeof(tracking));
113 tracking.spec.dst = (char *)orig_ref;
114 if (for_each_remote(find_tracked_branch, &tracking))
115 return 1;
116
117 if (!tracking.matches)
118 switch (track) {
119 case BRANCH_TRACK_ALWAYS:
120 case BRANCH_TRACK_EXPLICIT:
121 case BRANCH_TRACK_OVERRIDE:
122 break;
123 default:
124 return 1;
125 }
126
127 if (tracking.matches > 1)
128 return error("Not tracking: ambiguous information for ref %s",
129 orig_ref);
130
131 install_branch_config(BRANCH_CONFIG_VERBOSE, new_ref, tracking.remote,
132 tracking.src ? tracking.src : orig_ref);
133
134 free(tracking.src);
135 return 0;
136 }
137
138 int validate_new_branchname(const char *name, struct strbuf *ref,
139 int force, int attr_only)
140 {
141 if (strbuf_check_branch_ref(ref, name))
142 die("'%s' is not a valid branch name.", name);
143
144 if (!ref_exists(ref->buf))
145 return 0;
146 else if (!force && !attr_only)
147 die("A branch named '%s' already exists.", ref->buf + strlen("refs/heads/"));
148
149 if (!attr_only) {
150 const char *head;
151 unsigned char sha1[20];
152
153 head = resolve_ref("HEAD", sha1, 0, NULL);
154 if (!is_bare_repository() && head && !strcmp(head, ref->buf))
155 die("Cannot force update the current branch.");
156 }
157 return 1;
158 }
159
160 void create_branch(const char *head,
161 const char *name, const char *start_name,
162 int force, int reflog, enum branch_track track)
163 {
164 struct ref_lock *lock = NULL;
165 struct commit *commit;
166 unsigned char sha1[20];
167 char *real_ref, msg[PATH_MAX + 20];
168 struct strbuf ref = STRBUF_INIT;
169 int forcing = 0;
170 int dont_change_ref = 0;
171 int explicit_tracking = 0;
172
173 if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
174 explicit_tracking = 1;
175
176 if (validate_new_branchname(name, &ref, force,
177 track == BRANCH_TRACK_OVERRIDE)) {
178 if (!force)
179 dont_change_ref = 1;
180 else
181 forcing = 1;
182 }
183
184 real_ref = NULL;
185 if (get_sha1(start_name, sha1))
186 die("Not a valid object name: '%s'.", start_name);
187
188 switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
189 case 0:
190 /* Not branching from any existing branch */
191 if (explicit_tracking)
192 die("Cannot setup tracking information; starting point is not a branch.");
193 break;
194 case 1:
195 /* Unique completion -- good, only if it is a real branch */
196 if (prefixcmp(real_ref, "refs/heads/") &&
197 prefixcmp(real_ref, "refs/remotes/")) {
198 if (explicit_tracking)
199 die("Cannot setup tracking information; starting point is not a branch.");
200 else
201 real_ref = NULL;
202 }
203 break;
204 default:
205 die("Ambiguous object name: '%s'.", start_name);
206 break;
207 }
208
209 if ((commit = lookup_commit_reference(sha1)) == NULL)
210 die("Not a valid branch point: '%s'.", start_name);
211 hashcpy(sha1, commit->object.sha1);
212
213 if (!dont_change_ref) {
214 lock = lock_any_ref_for_update(ref.buf, NULL, 0);
215 if (!lock)
216 die_errno("Failed to lock ref for update");
217 }
218
219 if (reflog)
220 log_all_ref_updates = 1;
221
222 if (forcing)
223 snprintf(msg, sizeof msg, "branch: Reset to %s",
224 start_name);
225 else if (!dont_change_ref)
226 snprintf(msg, sizeof msg, "branch: Created from %s",
227 start_name);
228
229 if (real_ref && track)
230 setup_tracking(ref.buf+11, real_ref, track);
231
232 if (!dont_change_ref)
233 if (write_ref_sha1(lock, sha1, msg) < 0)
234 die_errno("Failed to write ref");
235
236 strbuf_release(&ref);
237 free(real_ref);
238 }
239
240 void remove_branch_state(void)
241 {
242 unlink(git_path("CHERRY_PICK_HEAD"));
243 unlink(git_path("MERGE_HEAD"));
244 unlink(git_path("MERGE_RR"));
245 unlink(git_path("MERGE_MSG"));
246 unlink(git_path("MERGE_MODE"));
247 unlink(git_path("SQUASH_MSG"));
248 }