branch.c

   1 #include "git-compat-util.h"
   2 #include "cache.h"
   3 #include "branch.h"
   4 #include "refs.h"
   5 #include "remote.h"
   6 #include "commit.h"
   7
   8 struct tracking {
   9         struct refspec spec;
  10         char *src;
  11         const char *remote;
  12         int matches;
  13 };
  14
  15 static int find_tracked_branch(struct remote *remote, void *priv)
  16 {
  17         struct tracking *tracking = priv;
  18
  19         if (!remote_find_tracking(remote, &tracking->spec)) {
  20                 if (++tracking->matches == 1) {
  21                         tracking->src = tracking->spec.src;
  22                         tracking->remote = remote->name;
  23                 } else {
  24                         free(tracking->spec.src);
  25                         if (tracking->src) {
  26                                 free(tracking->src);
  27                                 tracking->src = NULL;
  28                         }
  29                 }
  30                 tracking->spec.src = NULL;
  31         }
  32
  33         return 0;
  34 }
  35
  36 static int should_setup_rebase(const char *origin)
  37 {
  38         switch (autorebase) {
  39         case AUTOREBASE_NEVER:
  40                 return 0;
  41         case AUTOREBASE_LOCAL:
  42                 return origin == NULL;
  43         case AUTOREBASE_REMOTE:
  44                 return origin != NULL;
  45         case AUTOREBASE_ALWAYS:
  46                 return 1;
  47         }
  48         return 0;
  49 }
  50
  51 void install_branch_config(int flag, const char *local, const char *origin, const char *remote)
  52 {
  53         const char *shortname = skip_prefix(remote, "refs/heads/");
  54         struct strbuf key = STRBUF_INIT;
  55         int rebasing = should_setup_rebase(origin);
  56
  57         if (shortname
  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 (shortname && origin)
  81                         printf_ln(rebasing ?
  82                                   _("Branch %s set up to track remote branch %s from %s by rebasing.") :
  83                                   _("Branch %s set up to track remote branch %s from %s."),
  84                                   local, shortname, origin);
  85                 else if (shortname && !origin)
  86                         printf_ln(rebasing ?
  87                                   _("Branch %s set up to track local branch %s by rebasing.") :
  88                                   _("Branch %s set up to track local branch %s."),
  89                                   local, shortname);
  90                 else if (!shortname && origin)
  91                         printf_ln(rebasing ?
  92                                   _("Branch %s set up to track remote ref %s by rebasing.") :
  93                                   _("Branch %s set up to track remote ref %s."),
  94                                   local, remote);
  95                 else if (!shortname && !origin)
  96                         printf_ln(rebasing ?
  97                                   _("Branch %s set up to track local ref %s by rebasing.") :
  98                                   _("Branch %s set up to track local ref %s."),
  99                                   local, remote);
 100                 else
 101                         die("BUG: impossible combination of %p and %p",
 102                             shortname, 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         memset(&tracking, 0, sizeof(tracking));
 118         tracking.spec.dst = (char *)orig_ref;
 119         if (for_each_remote(find_tracked_branch, &tracking))
 120                 return 1;
 121
 122         if (!tracking.matches)
 123                 switch (track) {
 124                 case BRANCH_TRACK_ALWAYS:
 125                 case BRANCH_TRACK_EXPLICIT:
 126                 case BRANCH_TRACK_OVERRIDE:
 127                         break;
 128                 default:
 129                         return 1;
 130                 }
 131
 132         if (tracking.matches > 1)
 133                 return error(_("Not tracking: ambiguous information for ref %s"),
 134                                 orig_ref);
 135
 136         install_branch_config(config_flags, new_ref, tracking.remote,
 137                               tracking.src ? tracking.src : orig_ref);
 138
 139         free(tracking.src);
 140         return 0;
 141 }
 142
 143 struct branch_desc_cb {
 144         const char *config_name;
 145         const char *value;
 146 };
 147
 148 static int read_branch_desc_cb(const char *var, const char *value, void *cb)
 149 {
 150         struct branch_desc_cb *desc = cb;
 151         if (strcmp(desc->config_name, var))
 152                 return 0;
 153         free((char *)desc->value);
 154         return git_config_string(&desc->value, var, value);
 155 }
 156
 157 int read_branch_desc(struct strbuf *buf, const char *branch_name)
 158 {
 159         struct branch_desc_cb cb;
 160         struct strbuf name = STRBUF_INIT;
 161         strbuf_addf(&name, "branch.%s.description", branch_name);
 162         cb.config_name = name.buf;
 163         cb.value = NULL;
 164         if (git_config(read_branch_desc_cb, &cb) < 0) {
 165                 strbuf_release(&name);
 166                 return -1;
 167         }
 168         if (cb.value)
 169                 strbuf_addstr(buf, cb.value);
 170         strbuf_release(&name);
 171         return 0;
 172 }
 173
 174 int validate_new_branchname(const char *name, struct strbuf *ref,
 175                             int force, int attr_only)
 176 {
 177         if (strbuf_check_branch_ref(ref, name))
 178                 die(_("'%s' is not a valid branch name."), name);
 179
 180         if (!ref_exists(ref->buf))
 181                 return 0;
 182         else if (!force && !attr_only)
 183                 die(_("A branch named '%s' already exists."), ref->buf + strlen("refs/heads/"));
 184
 185         if (!attr_only) {
 186                 const char *head;
 187                 unsigned char sha1[20];
 188
 189                 head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);
 190                 if (!is_bare_repository() && head && !strcmp(head, ref->buf))
 191                         die(_("Cannot force update the current branch."));
 192         }
 193         return 1;
 194 }
 195
 196 static int check_tracking_branch(struct remote *remote, void *cb_data)
 197 {
 198         char *tracking_branch = cb_data;
 199         struct refspec query;
 200         memset(&query, 0, sizeof(struct refspec));
 201         query.dst = tracking_branch;
 202         return !remote_find_tracking(remote, &query);
 203 }
 204
 205 static int validate_remote_tracking_branch(char *ref)
 206 {
 207         return !for_each_remote(check_tracking_branch, ref);
 208 }
 209
 210 static const char upstream_not_branch[] =
 211 N_("Cannot setup tracking information; starting point '%s' is not a branch.");
 212 static const char upstream_missing[] =
 213 N_("the requested upstream branch '%s' does not exist");
 214 static const char upstream_advice[] =
 215 N_("\n"
 216 "If you are planning on basing your work on an upstream\n"
 217 "branch that already exists at the remote, you may need to\n"
 218 "run \"git fetch\" to retrieve it.\n"
 219 "\n"
 220 "If you are planning to push out a new local branch that\n"
 221 "will track its remote counterpart, you may want to use\n"
 222 "\"git push -u\" to set the upstream config as you push.");
 223
 224 void create_branch(const char *head,
 225                    const char *name, const char *start_name,
 226                    int force, int reflog, int clobber_head,
 227                    int quiet, enum branch_track track)
 228 {
 229         struct ref_lock *lock = NULL;
 230         struct commit *commit;
 231         unsigned char sha1[20];
 232         char *real_ref, msg[PATH_MAX + 20];
 233         struct strbuf ref = STRBUF_INIT;
 234         int forcing = 0;
 235         int dont_change_ref = 0;
 236         int explicit_tracking = 0;
 237
 238         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
 239                 explicit_tracking = 1;
 240
 241         if (validate_new_branchname(name, &ref, force,
 242                                     track == BRANCH_TRACK_OVERRIDE ||
 243                                     clobber_head)) {
 244                 if (!force)
 245                         dont_change_ref = 1;
 246                 else
 247                         forcing = 1;
 248         }
 249
 250         real_ref = NULL;
 251         if (get_sha1(start_name, sha1)) {
 252                 if (explicit_tracking) {
 253                         if (advice_set_upstream_failure) {
 254                                 error(_(upstream_missing), start_name);
 255                                 advise(_(upstream_advice));
 256                                 exit(1);
 257                         }
 258                         die(_(upstream_missing), start_name);
 259                 }
 260                 die(_("Not a valid object name: '%s'."), start_name);
 261         }
 262
 263         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
 264         case 0:
 265                 /* Not branching from any existing branch */
 266                 if (explicit_tracking)
 267                         die(_(upstream_not_branch), start_name);
 268                 break;
 269         case 1:
 270                 /* Unique completion -- good, only if it is a real branch */
 271                 if (!starts_with(real_ref, "refs/heads/") &&
 272                     validate_remote_tracking_branch(real_ref)) {
 273                         if (explicit_tracking)
 274                                 die(_(upstream_not_branch), start_name);
 275                         else
 276                                 real_ref = NULL;
 277                 }
 278                 break;
 279         default:
 280                 die(_("Ambiguous object name: '%s'."), start_name);
 281                 break;
 282         }
 283
 284         if ((commit = lookup_commit_reference(sha1)) == NULL)
 285                 die(_("Not a valid branch point: '%s'."), start_name);
 286         hashcpy(sha1, commit->object.sha1);
 287
 288         if (!dont_change_ref) {
 289                 lock = lock_any_ref_for_update(ref.buf, NULL, 0, NULL);
 290                 if (!lock)
 291                         die_errno(_("Failed to lock ref for update"));
 292         }
 293
 294         if (reflog)
 295                 log_all_ref_updates = 1;
 296
 297         if (forcing)
 298                 snprintf(msg, sizeof msg, "branch: Reset to %s",
 299                          start_name);
 300         else if (!dont_change_ref)
 301                 snprintf(msg, sizeof msg, "branch: Created from %s",
 302                          start_name);
 303
 304         if (real_ref && track)
 305                 setup_tracking(ref.buf + 11, real_ref, track, quiet);
 306
 307         if (!dont_change_ref)
 308                 if (write_ref_sha1(lock, sha1, msg) < 0)
 309                         die_errno(_("Failed to write ref"));
 310
 311         strbuf_release(&ref);
 312         free(real_ref);
 313 }
 314
 315 void remove_branch_state(void)
 316 {
 317         unlink(git_path("CHERRY_PICK_HEAD"));
 318         unlink(git_path("REVERT_HEAD"));
 319         unlink(git_path("MERGE_HEAD"));
 320         unlink(git_path("MERGE_RR"));
 321         unlink(git_path("MERGE_MSG"));
 322         unlink(git_path("MERGE_MODE"));
 323         unlink(git_path("SQUASH_MSG"));
 324 }