merge-tree: fix typo in "both changed identically"
[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         strbuf_release(&key);
78
79         if (flag & BRANCH_CONFIG_VERBOSE) {
80                 if (remote_is_branch && origin)
81                         printf(rebasing ?
82                                "Branch %s set up to track remote branch %s from %s by rebasing.\n" :
83                                "Branch %s set up to track remote branch %s from %s.\n",
84                                local, shortname, origin);
85                 else if (remote_is_branch && !origin)
86                         printf(rebasing ?
87                                "Branch %s set up to track local branch %s by rebasing.\n" :
88                                "Branch %s set up to track local branch %s.\n",
89                                local, shortname);
90                 else if (!remote_is_branch && origin)
91                         printf(rebasing ?
92                                "Branch %s set up to track remote ref %s by rebasing.\n" :
93                                "Branch %s set up to track remote ref %s.\n",
94                                local, remote);
95                 else if (!remote_is_branch && !origin)
96                         printf(rebasing ?
97                                "Branch %s set up to track local ref %s by rebasing.\n" :
98                                "Branch %s set up to track local ref %s.\n",
99                                local, remote);
100                 else
101                         die("BUG: impossible combination of %d and %p",
102                             remote_is_branch, origin);
103         }
104 }
105
106 /*
107  * This is called when new_ref is branched off of orig_ref, and tries
108  * to infer the settings for branch.<new_ref>.{remote,merge} from the
109  * config.
110  */
111 static int setup_tracking(const char *new_ref, const char *orig_ref,
112                           enum branch_track track, int quiet)
113 {
114         struct tracking tracking;
115         int config_flags = quiet ? 0 : BRANCH_CONFIG_VERBOSE;
116
117         if (strlen(new_ref) > 1024 - 7 - 7 - 1)
118                 return error("Tracking not set up: name too long: %s",
119                                 new_ref);
120
121         memset(&tracking, 0, sizeof(tracking));
122         tracking.spec.dst = (char *)orig_ref;
123         if (for_each_remote(find_tracked_branch, &tracking))
124                 return 1;
125
126         if (!tracking.matches)
127                 switch (track) {
128                 case BRANCH_TRACK_ALWAYS:
129                 case BRANCH_TRACK_EXPLICIT:
130                 case BRANCH_TRACK_OVERRIDE:
131                         break;
132                 default:
133                         return 1;
134                 }
135
136         if (tracking.matches > 1)
137                 return error("Not tracking: ambiguous information for ref %s",
138                                 orig_ref);
139
140         install_branch_config(config_flags, new_ref, tracking.remote,
141                               tracking.src ? tracking.src : orig_ref);
142
143         free(tracking.src);
144         return 0;
145 }
146
147 struct branch_desc_cb {
148         const char *config_name;
149         const char *value;
150 };
151
152 static int read_branch_desc_cb(const char *var, const char *value, void *cb)
153 {
154         struct branch_desc_cb *desc = cb;
155         if (strcmp(desc->config_name, var))
156                 return 0;
157         free((char *)desc->value);
158         return git_config_string(&desc->value, var, value);
159 }
160
161 int read_branch_desc(struct strbuf *buf, const char *branch_name)
162 {
163         struct branch_desc_cb cb;
164         struct strbuf name = STRBUF_INIT;
165         strbuf_addf(&name, "branch.%s.description", branch_name);
166         cb.config_name = name.buf;
167         cb.value = NULL;
168         if (git_config(read_branch_desc_cb, &cb) < 0) {
169                 strbuf_release(&name);
170                 return -1;
171         }
172         if (cb.value)
173                 strbuf_addstr(buf, cb.value);
174         strbuf_release(&name);
175         return 0;
176 }
177
178 int validate_new_branchname(const char *name, struct strbuf *ref,
179                             int force, int attr_only)
180 {
181         if (strbuf_check_branch_ref(ref, name))
182                 die("'%s' is not a valid branch name.", name);
183
184         if (!ref_exists(ref->buf))
185                 return 0;
186         else if (!force && !attr_only)
187                 die("A branch named '%s' already exists.", ref->buf + strlen("refs/heads/"));
188
189         if (!attr_only) {
190                 const char *head;
191                 unsigned char sha1[20];
192
193                 head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);
194                 if (!is_bare_repository() && head && !strcmp(head, ref->buf))
195                         die("Cannot force update the current branch.");
196         }
197         return 1;
198 }
199
200 void create_branch(const char *head,
201                    const char *name, const char *start_name,
202                    int force, int reflog, int clobber_head,
203                    int quiet, enum branch_track track)
204 {
205         struct ref_lock *lock = NULL;
206         struct commit *commit;
207         unsigned char sha1[20];
208         char *real_ref, msg[PATH_MAX + 20];
209         struct strbuf ref = STRBUF_INIT;
210         int forcing = 0;
211         int dont_change_ref = 0;
212         int explicit_tracking = 0;
213
214         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
215                 explicit_tracking = 1;
216
217         if (validate_new_branchname(name, &ref, force,
218                                     track == BRANCH_TRACK_OVERRIDE ||
219                                     clobber_head)) {
220                 if (!force)
221                         dont_change_ref = 1;
222                 else
223                         forcing = 1;
224         }
225
226         real_ref = NULL;
227         if (get_sha1(start_name, sha1))
228                 die("Not a valid object name: '%s'.", start_name);
229
230         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
231         case 0:
232                 /* Not branching from any existing branch */
233                 if (explicit_tracking)
234                         die("Cannot setup tracking information; starting point is not a branch.");
235                 break;
236         case 1:
237                 /* Unique completion -- good, only if it is a real branch */
238                 if (prefixcmp(real_ref, "refs/heads/") &&
239                     prefixcmp(real_ref, "refs/remotes/")) {
240                         if (explicit_tracking)
241                                 die("Cannot setup tracking information; starting point is not a branch.");
242                         else
243                                 real_ref = NULL;
244                 }
245                 break;
246         default:
247                 die("Ambiguous object name: '%s'.", start_name);
248                 break;
249         }
250
251         if ((commit = lookup_commit_reference(sha1)) == NULL)
252                 die("Not a valid branch point: '%s'.", start_name);
253         hashcpy(sha1, commit->object.sha1);
254
255         if (!dont_change_ref) {
256                 lock = lock_any_ref_for_update(ref.buf, NULL, 0);
257                 if (!lock)
258                         die_errno("Failed to lock ref for update");
259         }
260
261         if (reflog)
262                 log_all_ref_updates = 1;
263
264         if (forcing)
265                 snprintf(msg, sizeof msg, "branch: Reset to %s",
266                          start_name);
267         else if (!dont_change_ref)
268                 snprintf(msg, sizeof msg, "branch: Created from %s",
269                          start_name);
270
271         if (real_ref && track)
272                 setup_tracking(ref.buf+11, real_ref, track, quiet);
273
274         if (!dont_change_ref)
275                 if (write_ref_sha1(lock, sha1, msg) < 0)
276                         die_errno("Failed to write ref");
277
278         strbuf_release(&ref);
279         free(real_ref);
280 }
281
282 void remove_branch_state(void)
283 {
284         unlink(git_path("CHERRY_PICK_HEAD"));
285         unlink(git_path("REVERT_HEAD"));
286         unlink(git_path("MERGE_HEAD"));
287         unlink(git_path("MERGE_RR"));
288         unlink(git_path("MERGE_MSG"));
289         unlink(git_path("MERGE_MODE"));
290         unlink(git_path("SQUASH_MSG"));
291 }