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 = NULL;
  54         struct strbuf key = STRBUF_INIT;
  55         int rebasing = should_setup_rebase(origin);
  56
  57         if (skip_prefix(remote, "refs/heads/", &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) {
  81                         if (origin)
  82                                 printf_ln(rebasing ?
  83                                           _("Branch %s set up to track remote branch %s from %s by rebasing.") :
  84                                           _("Branch %s set up to track remote branch %s from %s."),
  85                                           local, shortname, origin);
  86                         else
  87                                 printf_ln(rebasing ?
  88                                           _("Branch %s set up to track local branch %s by rebasing.") :
  89                                           _("Branch %s set up to track local branch %s."),
  90                                           local, shortname);
  91                 } else {
  92                         if (origin)
  93                                 printf_ln(rebasing ?
  94                                           _("Branch %s set up to track remote ref %s by rebasing.") :
  95                                           _("Branch %s set up to track remote ref %s."),
  96                                           local, remote);
  97                         else
  98                                 printf_ln(rebasing ?
  99                                           _("Branch %s set up to track local ref %s by rebasing.") :
 100                                           _("Branch %s set up to track local ref %s."),
 101                                           local, remote);
 102                 }
 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 int read_branch_desc(struct strbuf *buf, const char *branch_name)
 144 {
 145         char *v = NULL;
 146         struct strbuf name = STRBUF_INIT;
 147         strbuf_addf(&name, "branch.%s.description", branch_name);
 148         if (git_config_get_string(name.buf, &v)) {
 149                 strbuf_release(&name);
 150                 return -1;
 151         }
 152         strbuf_addstr(buf, v);
 153         free(v);
 154         strbuf_release(&name);
 155         return 0;
 156 }
 157
 158 int validate_new_branchname(const char *name, struct strbuf *ref,
 159                             int force, int attr_only)
 160 {
 161         if (strbuf_check_branch_ref(ref, name))
 162                 die(_("'%s' is not a valid branch name."), name);
 163
 164         if (!ref_exists(ref->buf))
 165                 return 0;
 166         else if (!force && !attr_only)
 167                 die(_("A branch named '%s' already exists."), ref->buf + strlen("refs/heads/"));
 168
 169         if (!attr_only) {
 170                 const char *head;
 171                 unsigned char sha1[20];
 172
 173                 head = resolve_ref_unsafe("HEAD", sha1, 0, NULL);
 174                 if (!is_bare_repository() && head && !strcmp(head, ref->buf))
 175                         die(_("Cannot force update the current branch."));
 176         }
 177         return 1;
 178 }
 179
 180 static int check_tracking_branch(struct remote *remote, void *cb_data)
 181 {
 182         char *tracking_branch = cb_data;
 183         struct refspec query;
 184         memset(&query, 0, sizeof(struct refspec));
 185         query.dst = tracking_branch;
 186         return !remote_find_tracking(remote, &query);
 187 }
 188
 189 static int validate_remote_tracking_branch(char *ref)
 190 {
 191         return !for_each_remote(check_tracking_branch, ref);
 192 }
 193
 194 static const char upstream_not_branch[] =
 195 N_("Cannot setup tracking information; starting point '%s' is not a branch.");
 196 static const char upstream_missing[] =
 197 N_("the requested upstream branch '%s' does not exist");
 198 static const char upstream_advice[] =
 199 N_("\n"
 200 "If you are planning on basing your work on an upstream\n"
 201 "branch that already exists at the remote, you may need to\n"
 202 "run \"git fetch\" to retrieve it.\n"
 203 "\n"
 204 "If you are planning to push out a new local branch that\n"
 205 "will track its remote counterpart, you may want to use\n"
 206 "\"git push -u\" to set the upstream config as you push.");
 207
 208 void create_branch(const char *head,
 209                    const char *name, const char *start_name,
 210                    int force, int reflog, int clobber_head,
 211                    int quiet, enum branch_track track)
 212 {
 213         struct ref_lock *lock = NULL;
 214         struct commit *commit;
 215         unsigned char sha1[20];
 216         char *real_ref, msg[PATH_MAX + 20];
 217         struct strbuf ref = STRBUF_INIT;
 218         int forcing = 0;
 219         int dont_change_ref = 0;
 220         int explicit_tracking = 0;
 221
 222         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
 223                 explicit_tracking = 1;
 224
 225         if (validate_new_branchname(name, &ref, force,
 226                                     track == BRANCH_TRACK_OVERRIDE ||
 227                                     clobber_head)) {
 228                 if (!force)
 229                         dont_change_ref = 1;
 230                 else
 231                         forcing = 1;
 232         }
 233
 234         real_ref = NULL;
 235         if (get_sha1(start_name, sha1)) {
 236                 if (explicit_tracking) {
 237                         if (advice_set_upstream_failure) {
 238                                 error(_(upstream_missing), start_name);
 239                                 advise(_(upstream_advice));
 240                                 exit(1);
 241                         }
 242                         die(_(upstream_missing), start_name);
 243                 }
 244                 die(_("Not a valid object name: '%s'."), start_name);
 245         }
 246
 247         switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
 248         case 0:
 249                 /* Not branching from any existing branch */
 250                 if (explicit_tracking)
 251                         die(_(upstream_not_branch), start_name);
 252                 break;
 253         case 1:
 254                 /* Unique completion -- good, only if it is a real branch */
 255                 if (!starts_with(real_ref, "refs/heads/") &&
 256                     validate_remote_tracking_branch(real_ref)) {
 257                         if (explicit_tracking)
 258                                 die(_(upstream_not_branch), start_name);
 259                         else
 260                                 real_ref = NULL;
 261                 }
 262                 break;
 263         default:
 264                 die(_("Ambiguous object name: '%s'."), start_name);
 265                 break;
 266         }
 267
 268         if ((commit = lookup_commit_reference(sha1)) == NULL)
 269                 die(_("Not a valid branch point: '%s'."), start_name);
 270         hashcpy(sha1, commit->object.sha1);
 271
 272         if (!dont_change_ref) {
 273                 lock = lock_any_ref_for_update(ref.buf, NULL, 0, NULL);
 274                 if (!lock)
 275                         die_errno(_("Failed to lock ref for update"));
 276         }
 277
 278         if (reflog)
 279                 log_all_ref_updates = 1;
 280
 281         if (forcing)
 282                 snprintf(msg, sizeof msg, "branch: Reset to %s",
 283                          start_name);
 284         else if (!dont_change_ref)
 285                 snprintf(msg, sizeof msg, "branch: Created from %s",
 286                          start_name);
 287
 288         if (real_ref && track)
 289                 setup_tracking(ref.buf + 11, real_ref, track, quiet);
 290
 291         if (!dont_change_ref)
 292                 if (write_ref_sha1(lock, sha1, msg) < 0)
 293                         die_errno(_("Failed to write ref"));
 294
 295         strbuf_release(&ref);
 296         free(real_ref);
 297 }
 298
 299 void remove_branch_state(void)
 300 {
 301         unlink(git_path("CHERRY_PICK_HEAD"));
 302         unlink(git_path("REVERT_HEAD"));
 303         unlink(git_path("MERGE_HEAD"));
 304         unlink(git_path("MERGE_RR"));
 305         unlink(git_path("MERGE_MSG"));
 306         unlink(git_path("MERGE_MODE"));
 307         unlink(git_path("SQUASH_MSG"));
 308 }