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         struct strbuf key = STRBUF_INIT;
  53         int rebasing = should_setup_rebase(origin);
  54
  55         strbuf_addf(&key, "branch.%s.remote", local);
  56         git_config_set(key.buf, origin ? origin : ".");
  57
  58         strbuf_reset(&key);
  59         strbuf_addf(&key, "branch.%s.merge", local);
  60         git_config_set(key.buf, remote);
  61
  62         if (rebasing) {
  63                 strbuf_reset(&key);
  64                 strbuf_addf(&key, "branch.%s.rebase", local);
  65                 git_config_set(key.buf, "true");
  66         }
  67
  68         if (flag & BRANCH_CONFIG_VERBOSE)
  69                 printf("Branch %s set up to track %s branch %s %s.\n",
  70                        local,
  71                        origin ? "remote" : "local",
  72                        remote,
  73                        rebasing ? "by rebasing" : "by merging");
  74         strbuf_release(&key);
  75 }
  76
  77 /*
  78  * This is called when new_ref is branched off of orig_ref, and tries
  79  * to infer the settings for branch.<new_ref>.{remote,merge} from the
  80  * config.
  81  */
  82 static int setup_tracking(const char *new_ref, const char *orig_ref,
  83                           enum branch_track track)
  84 {
  85         struct tracking tracking;
  86
  87         if (strlen(new_ref) > 1024 - 7 - 7 - 1)
  88                 return error("Tracking not set up: name too long: %s",
  89                                 new_ref);
  90
  91         memset(&tracking, 0, sizeof(tracking));
  92         tracking.spec.dst = (char *)orig_ref;
  93         if (for_each_remote(find_tracked_branch, &tracking))
  94                 return 1;
  95
  96         if (!tracking.matches)
  97                 switch (track) {
  98                 case BRANCH_TRACK_ALWAYS:
  99                 case BRANCH_TRACK_EXPLICIT:
 100                         break;
 101                 default:
 102                         return 1;
 103                 }
 104
 105         if (tracking.matches > 1)
 106                 return error("Not tracking: ambiguous information for ref %s",
 107                                 orig_ref);
 108
 109         install_branch_config(BRANCH_CONFIG_VERBOSE, new_ref, tracking.remote,
 110                               tracking.src ? tracking.src : orig_ref);
 111
 112         free(tracking.src);
 113         return 0;
 114 }
 115
 116 void create_branch(const char *head,
 117                    const char *name, const char *start_name,
 118                    int force, int reflog, enum branch_track track)
 119 {
 120         struct ref_lock *lock;
 121         struct commit *commit;
 122         unsigned char sha1[20];
 123         char *real_ref, msg[PATH_MAX + 20];
 124         struct strbuf ref = STRBUF_INIT;
 125         int forcing = 0;
 126         int len;
 127
 128         len = strlen(name);
 129         if (interpret_nth_last_branch(name, &ref) != len) {
 130                 strbuf_reset(&ref);
 131                 strbuf_add(&ref, name, len);
 132         }
 133         strbuf_splice(&ref, 0, 0, "refs/heads/", 11);
 134
 135         if (check_ref_format(ref.buf))
 136                 die("'%s' is not a valid branch name.", name);
 137
 138         if (resolve_ref(ref.buf, sha1, 1, NULL)) {
 139                 if (!force)
 140                         die("A branch named '%s' already exists.", name);
 141                 else if (!is_bare_repository() && !strcmp(head, name))
 142                         die("Cannot force update the current branch.");
 143                 forcing = 1;
 144         }
 145
 146         real_ref = NULL;
 147         if (get_sha1(start_name, sha1))
 148                 die("Not a valid object name: '%s'.", start_name);
 149
 150         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
 151         case 0:
 152                 /* Not branching from any existing branch */
 153                 if (track == BRANCH_TRACK_EXPLICIT)
 154                         die("Cannot setup tracking information; starting point is not a branch.");
 155                 break;
 156         case 1:
 157                 /* Unique completion -- good, only if it is a real ref */
 158                 if (track == BRANCH_TRACK_EXPLICIT && !strcmp(real_ref, "HEAD"))
 159                         die("Cannot setup tracking information; starting point is not a branch.");
 160                 break;
 161         default:
 162                 die("Ambiguous object name: '%s'.", start_name);
 163                 break;
 164         }
 165
 166         if ((commit = lookup_commit_reference(sha1)) == NULL)
 167                 die("Not a valid branch point: '%s'.", start_name);
 168         hashcpy(sha1, commit->object.sha1);
 169
 170         lock = lock_any_ref_for_update(ref.buf, NULL, 0);
 171         if (!lock)
 172                 die("Failed to lock ref for update: %s.", strerror(errno));
 173
 174         if (reflog)
 175                 log_all_ref_updates = 1;
 176
 177         if (forcing)
 178                 snprintf(msg, sizeof msg, "branch: Reset from %s",
 179                          start_name);
 180         else
 181                 snprintf(msg, sizeof msg, "branch: Created from %s",
 182                          start_name);
 183
 184         if (real_ref && track)
 185                 setup_tracking(name, real_ref, track);
 186
 187         if (write_ref_sha1(lock, sha1, msg) < 0)
 188                 die("Failed to write ref: %s.", strerror(errno));
 189
 190         strbuf_release(&ref);
 191         free(real_ref);
 192 }
 193
 194 void remove_branch_state(void)
 195 {
 196         unlink(git_path("MERGE_HEAD"));
 197         unlink(git_path("MERGE_RR"));
 198         unlink(git_path("MERGE_MSG"));
 199         unlink(git_path("MERGE_MODE"));
 200         unlink(git_path("SQUASH_MSG"));
 201 }