Merge gitk changes from Paul Mackerras at git://ozlabs.org/~paulus/gitk
[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 struct branch_desc_cb {
139         const char *config_name;
140         const char *value;
141 };
142
143 static int read_branch_desc_cb(const char *var, const char *value, void *cb)
144 {
145         struct branch_desc_cb *desc = cb;
146         if (strcmp(desc->config_name, var))
147                 return 0;
148         free((char *)desc->value);
149         return git_config_string(&desc->value, var, value);
150 }
151
152 int read_branch_desc(struct strbuf *buf, const char *branch_name)
153 {
154         struct branch_desc_cb cb;
155         struct strbuf name = STRBUF_INIT;
156         strbuf_addf(&name, "branch.%s.description", branch_name);
157         cb.config_name = name.buf;
158         cb.value = NULL;
159         if (git_config(read_branch_desc_cb, &cb) < 0) {
160                 strbuf_release(&name);
161                 return -1;
162         }
163         if (cb.value)
164                 strbuf_addstr(buf, cb.value);
165         strbuf_release(&name);
166         return 0;
167 }
168
169 int validate_new_branchname(const char *name, struct strbuf *ref,
170                             int force, int attr_only)
171 {
172         if (strbuf_check_branch_ref(ref, name))
173                 die("'%s' is not a valid branch name.", name);
174
175         if (!ref_exists(ref->buf))
176                 return 0;
177         else if (!force && !attr_only)
178                 die("A branch named '%s' already exists.", ref->buf + strlen("refs/heads/"));
179
180         if (!attr_only) {
181                 const char *head;
182                 unsigned char sha1[20];
183
184                 head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);
185                 if (!is_bare_repository() && head && !strcmp(head, ref->buf))
186                         die("Cannot force update the current branch.");
187         }
188         return 1;
189 }
190
191 void create_branch(const char *head,
192                    const char *name, const char *start_name,
193                    int force, int reflog, int clobber_head,
194                    enum branch_track track)
195 {
196         struct ref_lock *lock = NULL;
197         struct commit *commit;
198         unsigned char sha1[20];
199         char *real_ref, msg[PATH_MAX + 20];
200         struct strbuf ref = STRBUF_INIT;
201         int forcing = 0;
202         int dont_change_ref = 0;
203         int explicit_tracking = 0;
204
205         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
206                 explicit_tracking = 1;
207
208         if (validate_new_branchname(name, &ref, force,
209                                     track == BRANCH_TRACK_OVERRIDE ||
210                                     clobber_head)) {
211                 if (!force)
212                         dont_change_ref = 1;
213                 else
214                         forcing = 1;
215         }
216
217         real_ref = NULL;
218         if (get_sha1(start_name, sha1))
219                 die("Not a valid object name: '%s'.", start_name);
220
221         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
222         case 0:
223                 /* Not branching from any existing branch */
224                 if (explicit_tracking)
225                         die("Cannot setup tracking information; starting point is not a branch.");
226                 break;
227         case 1:
228                 /* Unique completion -- good, only if it is a real branch */
229                 if (prefixcmp(real_ref, "refs/heads/") &&
230                     prefixcmp(real_ref, "refs/remotes/")) {
231                         if (explicit_tracking)
232                                 die("Cannot setup tracking information; starting point is not a branch.");
233                         else
234                                 real_ref = NULL;
235                 }
236                 break;
237         default:
238                 die("Ambiguous object name: '%s'.", start_name);
239                 break;
240         }
241
242         if ((commit = lookup_commit_reference(sha1)) == NULL)
243                 die("Not a valid branch point: '%s'.", start_name);
244         hashcpy(sha1, commit->object.sha1);
245
246         if (!dont_change_ref) {
247                 lock = lock_any_ref_for_update(ref.buf, NULL, 0);
248                 if (!lock)
249                         die_errno("Failed to lock ref for update");
250         }
251
252         if (reflog)
253                 log_all_ref_updates = 1;
254
255         if (forcing)
256                 snprintf(msg, sizeof msg, "branch: Reset to %s",
257                          start_name);
258         else if (!dont_change_ref)
259                 snprintf(msg, sizeof msg, "branch: Created from %s",
260                          start_name);
261
262         if (real_ref && track)
263                 setup_tracking(ref.buf+11, real_ref, track);
264
265         if (!dont_change_ref)
266                 if (write_ref_sha1(lock, sha1, msg) < 0)
267                         die_errno("Failed to write ref");
268
269         strbuf_release(&ref);
270         free(real_ref);
271 }
272
273 void remove_branch_state(void)
274 {
275         unlink(git_path("CHERRY_PICK_HEAD"));
276         unlink(git_path("REVERT_HEAD"));
277         unlink(git_path("MERGE_HEAD"));
278         unlink(git_path("MERGE_RR"));
279         unlink(git_path("MERGE_MSG"));
280         unlink(git_path("MERGE_MODE"));
281         unlink(git_path("SQUASH_MSG"));
282 }