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 static const char upstream_not_branch[] =
 201 N_("Cannot setup tracking information; starting point '%s' is not a branch.");
 202 static const char upstream_missing[] =
 203 N_("the requested upstream branch '%s' does not exist");
 204 static const char upstream_advice[] =
 205 N_("\n"
 206 "If you are planning on basing your work on an upstream\n"
 207 "branch that already exists at the remote, you may need to\n"
 208 "run \"git fetch\" to retrieve it.\n"
 209 "\n"
 210 "If you are planning to push out a new local branch that\n"
 211 "will track its remote counterpart, you may want to use\n"
 212 "\"git push -u\" to set the upstream config as you push.");
 213
 214 void create_branch(const char *head,
 215                    const char *name, const char *start_name,
 216                    int force, int reflog, int clobber_head,
 217                    int quiet, enum branch_track track)
 218 {
 219         struct ref_lock *lock = NULL;
 220         struct commit *commit;
 221         unsigned char sha1[20];
 222         char *real_ref, msg[PATH_MAX + 20];
 223         struct strbuf ref = STRBUF_INIT;
 224         int forcing = 0;
 225         int dont_change_ref = 0;
 226         int explicit_tracking = 0;
 227
 228         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
 229                 explicit_tracking = 1;
 230
 231         if (validate_new_branchname(name, &ref, force,
 232                                     track == BRANCH_TRACK_OVERRIDE ||
 233                                     clobber_head)) {
 234                 if (!force)
 235                         dont_change_ref = 1;
 236                 else
 237                         forcing = 1;
 238         }
 239
 240         real_ref = NULL;
 241         if (get_sha1(start_name, sha1)) {
 242                 if (explicit_tracking) {
 243                         if (advice_set_upstream_failure) {
 244                                 error(_(upstream_missing), start_name);
 245                                 advise(_(upstream_advice));
 246                                 exit(1);
 247                         }
 248                         die(_(upstream_missing), start_name);
 249                 }
 250                 die("Not a valid object name: '%s'.", start_name);
 251         }
 252
 253         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
 254         case 0:
 255                 /* Not branching from any existing branch */
 256                 if (explicit_tracking)
 257                         die(_(upstream_not_branch), start_name);
 258                 break;
 259         case 1:
 260                 /* Unique completion -- good, only if it is a real branch */
 261                 if (prefixcmp(real_ref, "refs/heads/") &&
 262                     prefixcmp(real_ref, "refs/remotes/")) {
 263                         if (explicit_tracking)
 264                                 die(_(upstream_not_branch), start_name);
 265                         else
 266                                 real_ref = NULL;
 267                 }
 268                 break;
 269         default:
 270                 die("Ambiguous object name: '%s'.", start_name);
 271                 break;
 272         }
 273
 274         if ((commit = lookup_commit_reference(sha1)) == NULL)
 275                 die("Not a valid branch point: '%s'.", start_name);
 276         hashcpy(sha1, commit->object.sha1);
 277
 278         if (!dont_change_ref) {
 279                 lock = lock_any_ref_for_update(ref.buf, NULL, 0);
 280                 if (!lock)
 281                         die_errno("Failed to lock ref for update");
 282         }
 283
 284         if (reflog)
 285                 log_all_ref_updates = 1;
 286
 287         if (forcing)
 288                 snprintf(msg, sizeof msg, "branch: Reset to %s",
 289                          start_name);
 290         else if (!dont_change_ref)
 291                 snprintf(msg, sizeof msg, "branch: Created from %s",
 292                          start_name);
 293
 294         if (real_ref && track)
 295                 setup_tracking(ref.buf+11, real_ref, track, quiet);
 296
 297         if (!dont_change_ref)
 298                 if (write_ref_sha1(lock, sha1, msg) < 0)
 299                         die_errno("Failed to write ref");
 300
 301         strbuf_release(&ref);
 302         free(real_ref);
 303 }
 304
 305 void remove_branch_state(void)
 306 {
 307         unlink(git_path("CHERRY_PICK_HEAD"));
 308         unlink(git_path("REVERT_HEAD"));
 309         unlink(git_path("MERGE_HEAD"));
 310         unlink(git_path("MERGE_RR"));
 311         unlink(git_path("MERGE_MSG"));
 312         unlink(git_path("MERGE_MODE"));
 313         unlink(git_path("SQUASH_MSG"));
 314 }