Merge branch 'jc/maint-rebase-rewrite-last-skip'
[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 void create_branch(const char *head,
139                    const char *name, const char *start_name,
140                    int force, int reflog, enum branch_track track)
141 {
142         struct ref_lock *lock = NULL;
143         struct commit *commit;
144         unsigned char sha1[20];
145         char *real_ref, msg[PATH_MAX + 20];
146         struct strbuf ref = STRBUF_INIT;
147         int forcing = 0;
148         int dont_change_ref = 0;
149         int explicit_tracking = 0;
150
151         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
152                 explicit_tracking = 1;
153
154         if (strbuf_check_branch_ref(&ref, name))
155                 die("'%s' is not a valid branch name.", name);
156
157         if (resolve_ref(ref.buf, sha1, 1, NULL)) {
158                 if (!force && track == BRANCH_TRACK_OVERRIDE)
159                         dont_change_ref = 1;
160                 else if (!force)
161                         die("A branch named '%s' already exists.", name);
162                 else if (!is_bare_repository() && head && !strcmp(head, name))
163                         die("Cannot force update the current branch.");
164                 forcing = 1;
165         }
166
167         real_ref = NULL;
168         if (get_sha1(start_name, sha1))
169                 die("Not a valid object name: '%s'.", start_name);
170
171         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
172         case 0:
173                 /* Not branching from any existing branch */
174                 if (explicit_tracking)
175                         die("Cannot setup tracking information; starting point is not a branch.");
176                 break;
177         case 1:
178                 /* Unique completion -- good, only if it is a real ref */
179                 if (explicit_tracking && !strcmp(real_ref, "HEAD"))
180                         die("Cannot setup tracking information; starting point is not a branch.");
181                 break;
182         default:
183                 die("Ambiguous object name: '%s'.", start_name);
184                 break;
185         }
186
187         if ((commit = lookup_commit_reference(sha1)) == NULL)
188                 die("Not a valid branch point: '%s'.", start_name);
189         hashcpy(sha1, commit->object.sha1);
190
191         if (!dont_change_ref) {
192                 lock = lock_any_ref_for_update(ref.buf, NULL, 0);
193                 if (!lock)
194                         die_errno("Failed to lock ref for update");
195         }
196
197         if (reflog)
198                 log_all_ref_updates = 1;
199
200         if (forcing)
201                 snprintf(msg, sizeof msg, "branch: Reset to %s",
202                          start_name);
203         else if (!dont_change_ref)
204                 snprintf(msg, sizeof msg, "branch: Created from %s",
205                          start_name);
206
207         if (real_ref && track)
208                 setup_tracking(name, real_ref, track);
209
210         if (!dont_change_ref)
211                 if (write_ref_sha1(lock, sha1, msg) < 0)
212                         die_errno("Failed to write ref");
213
214         strbuf_release(&ref);
215         free(real_ref);
216 }
217
218 void remove_branch_state(void)
219 {
220         unlink(git_path("MERGE_HEAD"));
221         unlink(git_path("MERGE_RR"));
222         unlink(git_path("MERGE_MSG"));
223         unlink(git_path("MERGE_MODE"));
224         unlink(git_path("SQUASH_MSG"));
225 }