branch.c

   1 #include "git-compat-util.h"
   2 #include "advice.h"
   3 #include "config.h"
   4 #include "branch.h"
   5 #include "environment.h"
   6 #include "gettext.h"
   7 #include "hex.h"
   8 #include "object-name.h"
   9 #include "path.h"
  10 #include "refs.h"
  11 #include "refspec.h"
  12 #include "remote.h"
  13 #include "repository.h"
  14 #include "sequencer.h"
  15 #include "commit.h"
  16 #include "worktree.h"
  17 #include "submodule-config.h"
  18 #include "run-command.h"
  19 #include "strmap.h"
  20
  21 struct tracking {
  22         struct refspec_item spec;
  23         struct string_list *srcs;
  24         const char *remote;
  25         int matches;
  26 };
  27
  28 struct find_tracked_branch_cb {
  29         struct tracking *tracking;
  30         struct string_list ambiguous_remotes;
  31 };
  32
  33 static int find_tracked_branch(struct remote *remote, void *priv)
  34 {
  35         struct find_tracked_branch_cb *ftb = priv;
  36         struct tracking *tracking = ftb->tracking;
  37
  38         if (!remote_find_tracking(remote, &tracking->spec)) {
  39                 switch (++tracking->matches) {
  40                 case 1:
  41                         string_list_append_nodup(tracking->srcs, tracking->spec.src);
  42                         tracking->remote = remote->name;
  43                         break;
  44                 case 2:
  45                         /* there are at least two remotes; backfill the first one */
  46                         string_list_append(&ftb->ambiguous_remotes, tracking->remote);
  47                         /* fall through */
  48                 default:
  49                         string_list_append(&ftb->ambiguous_remotes, remote->name);
  50                         free(tracking->spec.src);
  51                         string_list_clear(tracking->srcs, 0);
  52                 break;
  53                 }
  54                 /* remote_find_tracking() searches by src if present */
  55                 tracking->spec.src = NULL;
  56         }
  57         return 0;
  58 }
  59
  60 static int should_setup_rebase(const char *origin)
  61 {
  62         switch (autorebase) {
  63         case AUTOREBASE_NEVER:
  64                 return 0;
  65         case AUTOREBASE_LOCAL:
  66                 return origin == NULL;
  67         case AUTOREBASE_REMOTE:
  68                 return origin != NULL;
  69         case AUTOREBASE_ALWAYS:
  70                 return 1;
  71         }
  72         return 0;
  73 }
  74
  75 /**
  76  * Install upstream tracking configuration for a branch; specifically, add
  77  * `branch.<name>.remote` and `branch.<name>.merge` entries.
  78  *
  79  * `flag` contains integer flags for options; currently only
  80  * BRANCH_CONFIG_VERBOSE is checked.
  81  *
  82  * `local` is the name of the branch whose configuration we're installing.
  83  *
  84  * `origin` is the name of the remote owning the upstream branches. NULL means
  85  * the upstream branches are local to this repo.
  86  *
  87  * `remotes` is a list of refs that are upstream of local
  88  */
  89 static int install_branch_config_multiple_remotes(int flag, const char *local,
  90                 const char *origin, struct string_list *remotes)
  91 {
  92         const char *shortname = NULL;
  93         struct strbuf key = STRBUF_INIT;
  94         struct string_list_item *item;
  95         int rebasing = should_setup_rebase(origin);
  96
  97         if (!remotes->nr)
  98                 BUG("must provide at least one remote for branch config");
  99         if (rebasing && remotes->nr > 1)
 100                 die(_("cannot inherit upstream tracking configuration of "
 101                       "multiple refs when rebasing is requested"));
 102
 103         /*
 104          * If the new branch is trying to track itself, something has gone
 105          * wrong. Warn the user and don't proceed any further.
 106          */
 107         if (!origin)
 108                 for_each_string_list_item(item, remotes)
 109                         if (skip_prefix(item->string, "refs/heads/", &shortname)
 110                             && !strcmp(local, shortname)) {
 111                                 warning(_("not setting branch '%s' as its own upstream"),
 112                                         local);
 113                                 return 0;
 114                         }
 115
 116         strbuf_addf(&key, "branch.%s.remote", local);
 117         if (git_config_set_gently(key.buf, origin ? origin : ".") < 0)
 118                 goto out_err;
 119
 120         strbuf_reset(&key);
 121         strbuf_addf(&key, "branch.%s.merge", local);
 122         /*
 123          * We want to overwrite any existing config with all the branches in
 124          * "remotes". Override any existing config, then write our branches. If
 125          * more than one is provided, use CONFIG_REGEX_NONE to preserve what
 126          * we've written so far.
 127          */
 128         if (git_config_set_gently(key.buf, NULL) < 0)
 129                 goto out_err;
 130         for_each_string_list_item(item, remotes)
 131                 if (git_config_set_multivar_gently(key.buf, item->string, CONFIG_REGEX_NONE, 0) < 0)
 132                         goto out_err;
 133
 134         if (rebasing) {
 135                 strbuf_reset(&key);
 136                 strbuf_addf(&key, "branch.%s.rebase", local);
 137                 if (git_config_set_gently(key.buf, "true") < 0)
 138                         goto out_err;
 139         }
 140         strbuf_release(&key);
 141
 142         if (flag & BRANCH_CONFIG_VERBOSE) {
 143                 struct strbuf tmp_ref_name = STRBUF_INIT;
 144                 struct string_list friendly_ref_names = STRING_LIST_INIT_DUP;
 145
 146                 for_each_string_list_item(item, remotes) {
 147                         shortname = item->string;
 148                         skip_prefix(shortname, "refs/heads/", &shortname);
 149                         if (origin) {
 150                                 strbuf_addf(&tmp_ref_name, "%s/%s",
 151                                             origin, shortname);
 152                                 string_list_append_nodup(
 153                                         &friendly_ref_names,
 154                                         strbuf_detach(&tmp_ref_name, NULL));
 155                         } else {
 156                                 string_list_append(
 157                                         &friendly_ref_names, shortname);
 158                         }
 159                 }
 160
 161                 if (remotes->nr == 1) {
 162                         /*
 163                          * Rebasing is only allowed in the case of a single
 164                          * upstream branch.
 165                          */
 166                         printf_ln(rebasing ?
 167                                 _("branch '%s' set up to track '%s' by rebasing.") :
 168                                 _("branch '%s' set up to track '%s'."),
 169                                 local, friendly_ref_names.items[0].string);
 170                 } else {
 171                         printf_ln(_("branch '%s' set up to track:"), local);
 172                         for_each_string_list_item(item, &friendly_ref_names)
 173                                 printf_ln("  %s", item->string);
 174                 }
 175
 176                 string_list_clear(&friendly_ref_names, 0);
 177         }
 178
 179         return 0;
 180
 181 out_err:
 182         strbuf_release(&key);
 183         error(_("unable to write upstream branch configuration"));
 184
 185         advise(_("\nAfter fixing the error cause you may try to fix up\n"
 186                 "the remote tracking information by invoking:"));
 187         if (remotes->nr == 1)
 188                 advise("  git branch --set-upstream-to=%s%s%s",
 189                         origin ? origin : "",
 190                         origin ? "/" : "",
 191                         remotes->items[0].string);
 192         else {
 193                 advise("  git config --add branch.\"%s\".remote %s",
 194                         local, origin ? origin : ".");
 195                 for_each_string_list_item(item, remotes)
 196                         advise("  git config --add branch.\"%s\".merge %s",
 197                                 local, item->string);
 198         }
 199
 200         return -1;
 201 }
 202
 203 int install_branch_config(int flag, const char *local, const char *origin,
 204                 const char *remote)
 205 {
 206         int ret;
 207         struct string_list remotes = STRING_LIST_INIT_DUP;
 208
 209         string_list_append(&remotes, remote);
 210         ret = install_branch_config_multiple_remotes(flag, local, origin, &remotes);
 211         string_list_clear(&remotes, 0);
 212         return ret;
 213 }
 214
 215 static int inherit_tracking(struct tracking *tracking, const char *orig_ref)
 216 {
 217         const char *bare_ref;
 218         struct branch *branch;
 219         int i;
 220
 221         bare_ref = orig_ref;
 222         skip_prefix(orig_ref, "refs/heads/", &bare_ref);
 223
 224         branch = branch_get(bare_ref);
 225         if (!branch->remote_name) {
 226                 warning(_("asked to inherit tracking from '%s', but no remote is set"),
 227                         bare_ref);
 228                 return -1;
 229         }
 230
 231         if (branch->merge_nr < 1 || !branch->merge_name || !branch->merge_name[0]) {
 232                 warning(_("asked to inherit tracking from '%s', but no merge configuration is set"),
 233                         bare_ref);
 234                 return -1;
 235         }
 236
 237         tracking->remote = branch->remote_name;
 238         for (i = 0; i < branch->merge_nr; i++)
 239                 string_list_append(tracking->srcs, branch->merge_name[i]);
 240         return 0;
 241 }
 242
 243 /*
 244  * Used internally to set the branch.<new_ref>.{remote,merge} config
 245  * settings so that branch 'new_ref' tracks 'orig_ref'. Unlike
 246  * dwim_and_setup_tracking(), this does not do DWIM, i.e. "origin/main"
 247  * will not be expanded to "refs/remotes/origin/main", so it is not safe
 248  * for 'orig_ref' to be raw user input.
 249  */
 250 static void setup_tracking(const char *new_ref, const char *orig_ref,
 251                            enum branch_track track, int quiet)
 252 {
 253         struct tracking tracking;
 254         struct string_list tracking_srcs = STRING_LIST_INIT_DUP;
 255         int config_flags = quiet ? 0 : BRANCH_CONFIG_VERBOSE;
 256         struct find_tracked_branch_cb ftb_cb = {
 257                 .tracking = &tracking,
 258                 .ambiguous_remotes = STRING_LIST_INIT_DUP,
 259         };
 260
 261         if (!track)
 262                 BUG("asked to set up tracking, but tracking is disallowed");
 263
 264         memset(&tracking, 0, sizeof(tracking));
 265         tracking.spec.dst = (char *)orig_ref;
 266         tracking.srcs = &tracking_srcs;
 267         if (track != BRANCH_TRACK_INHERIT)
 268                 for_each_remote(find_tracked_branch, &ftb_cb);
 269         else if (inherit_tracking(&tracking, orig_ref))
 270                 goto cleanup;
 271
 272         if (!tracking.matches)
 273                 switch (track) {
 274                 /* If ref is not remote, still use local */
 275                 case BRANCH_TRACK_ALWAYS:
 276                 case BRANCH_TRACK_EXPLICIT:
 277                 case BRANCH_TRACK_OVERRIDE:
 278                 /* Remote matches not evaluated */
 279                 case BRANCH_TRACK_INHERIT:
 280                         break;
 281                 /* Otherwise, if no remote don't track */
 282                 default:
 283                         goto cleanup;
 284                 }
 285
 286         /*
 287          * This check does not apply to BRANCH_TRACK_INHERIT;
 288          * that supports multiple entries in tracking_srcs but
 289          * leaves tracking.matches at 0.
 290          */
 291         if (tracking.matches > 1) {
 292                 int status = die_message(_("not tracking: ambiguous information for ref '%s'"),
 293                                             orig_ref);
 294                 if (advice_enabled(ADVICE_AMBIGUOUS_FETCH_REFSPEC)) {
 295                         struct strbuf remotes_advice = STRBUF_INIT;
 296                         struct string_list_item *item;
 297
 298                         for_each_string_list_item(item, &ftb_cb.ambiguous_remotes)
 299                                 /*
 300                                  * TRANSLATORS: This is a line listing a remote with duplicate
 301                                  * refspecs in the advice message below. For RTL languages you'll
 302                                  * probably want to swap the "%s" and leading "  " space around.
 303                                  */
 304                                 strbuf_addf(&remotes_advice, _("  %s\n"), item->string);
 305
 306                         /*
 307                          * TRANSLATORS: The second argument is a \n-delimited list of
 308                          * duplicate refspecs, composed above.
 309                          */
 310                         advise(_("There are multiple remotes whose fetch refspecs map to the remote\n"
 311                                  "tracking ref '%s':\n"
 312                                  "%s"
 313                                  "\n"
 314                                  "This is typically a configuration error.\n"
 315                                  "\n"
 316                                  "To support setting up tracking branches, ensure that\n"
 317                                  "different remotes' fetch refspecs map into different\n"
 318                                  "tracking namespaces."), orig_ref,
 319                                remotes_advice.buf);
 320                         strbuf_release(&remotes_advice);
 321                 }
 322                 exit(status);
 323         }
 324
 325         if (track == BRANCH_TRACK_SIMPLE) {
 326                 /*
 327                  * Only track if remote branch name matches.
 328                  * Reaching into items[0].string is safe because
 329                  * we know there is at least one and not more than
 330                  * one entry (because only BRANCH_TRACK_INHERIT can
 331                  * produce more than one entry).
 332                  */
 333                 const char *tracked_branch;
 334                 if (!skip_prefix(tracking.srcs->items[0].string,
 335                                  "refs/heads/", &tracked_branch) ||
 336                     strcmp(tracked_branch, new_ref))
 337                         goto cleanup;
 338         }
 339
 340         if (tracking.srcs->nr < 1)
 341                 string_list_append(tracking.srcs, orig_ref);
 342         if (install_branch_config_multiple_remotes(config_flags, new_ref,
 343                                 tracking.remote, tracking.srcs) < 0)
 344                 exit(1);
 345
 346 cleanup:
 347         string_list_clear(&tracking_srcs, 0);
 348         string_list_clear(&ftb_cb.ambiguous_remotes, 0);
 349 }
 350
 351 int read_branch_desc(struct strbuf *buf, const char *branch_name)
 352 {
 353         char *v = NULL;
 354         struct strbuf name = STRBUF_INIT;
 355         strbuf_addf(&name, "branch.%s.description", branch_name);
 356         if (git_config_get_string(name.buf, &v)) {
 357                 strbuf_release(&name);
 358                 return -1;
 359         }
 360         strbuf_addstr(buf, v);
 361         free(v);
 362         strbuf_release(&name);
 363         return 0;
 364 }
 365
 366 /*
 367  * Check if 'name' can be a valid name for a branch; die otherwise.
 368  * Return 1 if the named branch already exists; return 0 otherwise.
 369  * Fill ref with the full refname for the branch.
 370  */
 371 int validate_branchname(const char *name, struct strbuf *ref)
 372 {
 373         if (strbuf_check_branch_ref(ref, name))
 374                 die(_("'%s' is not a valid branch name"), name);
 375
 376         return ref_exists(ref->buf);
 377 }
 378
 379 static int initialized_checked_out_branches;
 380 static struct strmap current_checked_out_branches = STRMAP_INIT;
 381
 382 static void prepare_checked_out_branches(void)
 383 {
 384         int i = 0;
 385         struct worktree **worktrees;
 386
 387         if (initialized_checked_out_branches)
 388                 return;
 389         initialized_checked_out_branches = 1;
 390
 391         worktrees = get_worktrees();
 392
 393         while (worktrees[i]) {
 394                 char *old;
 395                 struct wt_status_state state = { 0 };
 396                 struct worktree *wt = worktrees[i++];
 397                 struct string_list update_refs = STRING_LIST_INIT_DUP;
 398
 399                 if (wt->is_bare)
 400                         continue;
 401
 402                 if (wt->head_ref) {
 403                         old = strmap_put(&current_checked_out_branches,
 404                                          wt->head_ref,
 405                                          xstrdup(wt->path));
 406                         free(old);
 407                 }
 408
 409                 if (wt_status_check_rebase(wt, &state) &&
 410                     (state.rebase_in_progress || state.rebase_interactive_in_progress) &&
 411                     state.branch) {
 412                         struct strbuf ref = STRBUF_INIT;
 413                         strbuf_addf(&ref, "refs/heads/%s", state.branch);
 414                         old = strmap_put(&current_checked_out_branches,
 415                                          ref.buf,
 416                                          xstrdup(wt->path));
 417                         free(old);
 418                         strbuf_release(&ref);
 419                 }
 420                 wt_status_state_free_buffers(&state);
 421
 422                 if (wt_status_check_bisect(wt, &state) &&
 423                     state.bisecting_from) {
 424                         struct strbuf ref = STRBUF_INIT;
 425                         strbuf_addf(&ref, "refs/heads/%s", state.bisecting_from);
 426                         old = strmap_put(&current_checked_out_branches,
 427                                          ref.buf,
 428                                          xstrdup(wt->path));
 429                         free(old);
 430                         strbuf_release(&ref);
 431                 }
 432                 wt_status_state_free_buffers(&state);
 433
 434                 if (!sequencer_get_update_refs_state(get_worktree_git_dir(wt),
 435                                                      &update_refs)) {
 436                         struct string_list_item *item;
 437                         for_each_string_list_item(item, &update_refs) {
 438                                 old = strmap_put(&current_checked_out_branches,
 439                                                  item->string,
 440                                                  xstrdup(wt->path));
 441                                 free(old);
 442                         }
 443                         string_list_clear(&update_refs, 1);
 444                 }
 445         }
 446
 447         free_worktrees(worktrees);
 448 }
 449
 450 const char *branch_checked_out(const char *refname)
 451 {
 452         prepare_checked_out_branches();
 453         return strmap_get(&current_checked_out_branches, refname);
 454 }
 455
 456 /*
 457  * Check if a branch 'name' can be created as a new branch; die otherwise.
 458  * 'force' can be used when it is OK for the named branch already exists.
 459  * Return 1 if the named branch already exists; return 0 otherwise.
 460  * Fill ref with the full refname for the branch.
 461  */
 462 int validate_new_branchname(const char *name, struct strbuf *ref, int force)
 463 {
 464         const char *path;
 465         if (!validate_branchname(name, ref))
 466                 return 0;
 467
 468         if (!force)
 469                 die(_("a branch named '%s' already exists"),
 470                     ref->buf + strlen("refs/heads/"));
 471
 472         if ((path = branch_checked_out(ref->buf)))
 473                 die(_("cannot force update the branch '%s' "
 474                       "used by worktree at '%s'"),
 475                     ref->buf + strlen("refs/heads/"), path);
 476
 477         return 1;
 478 }
 479
 480 static int check_tracking_branch(struct remote *remote, void *cb_data)
 481 {
 482         char *tracking_branch = cb_data;
 483         struct refspec_item query;
 484         int res;
 485         memset(&query, 0, sizeof(struct refspec_item));
 486         query.dst = tracking_branch;
 487         res = !remote_find_tracking(remote, &query);
 488         free(query.src);
 489         return res;
 490 }
 491
 492 static int validate_remote_tracking_branch(char *ref)
 493 {
 494         return !for_each_remote(check_tracking_branch, ref);
 495 }
 496
 497 static const char upstream_not_branch[] =
 498 N_("cannot set up tracking information; starting point '%s' is not a branch");
 499 static const char upstream_missing[] =
 500 N_("the requested upstream branch '%s' does not exist");
 501 static const char upstream_advice[] =
 502 N_("\n"
 503 "If you are planning on basing your work on an upstream\n"
 504 "branch that already exists at the remote, you may need to\n"
 505 "run \"git fetch\" to retrieve it.\n"
 506 "\n"
 507 "If you are planning to push out a new local branch that\n"
 508 "will track its remote counterpart, you may want to use\n"
 509 "\"git push -u\" to set the upstream config as you push.");
 510
 511 /**
 512  * DWIMs a user-provided ref to determine the starting point for a
 513  * branch and validates it, where:
 514  *
 515  *   - r is the repository to validate the branch for
 516  *
 517  *   - start_name is the ref that we would like to test. This is
 518  *     expanded with DWIM and assigned to out_real_ref.
 519  *
 520  *   - track is the tracking mode of the new branch. If tracking is
 521  *     explicitly requested, start_name must be a branch (because
 522  *     otherwise start_name cannot be tracked)
 523  *
 524  *   - out_oid is an out parameter containing the object_id of start_name
 525  *
 526  *   - out_real_ref is an out parameter containing the full, 'real' form
 527  *     of start_name e.g. refs/heads/main instead of main
 528  *
 529  */
 530 static void dwim_branch_start(struct repository *r, const char *start_name,
 531                            enum branch_track track, char **out_real_ref,
 532                            struct object_id *out_oid)
 533 {
 534         struct commit *commit;
 535         struct object_id oid;
 536         char *real_ref;
 537         int explicit_tracking = 0;
 538
 539         if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
 540                 explicit_tracking = 1;
 541
 542         real_ref = NULL;
 543         if (repo_get_oid_mb(r, start_name, &oid)) {
 544                 if (explicit_tracking) {
 545                         int code = die_message(_(upstream_missing), start_name);
 546                         advise_if_enabled(ADVICE_SET_UPSTREAM_FAILURE,
 547                                           _(upstream_advice));
 548                         exit(code);
 549                 }
 550                 die(_("not a valid object name: '%s'"), start_name);
 551         }
 552
 553         switch (repo_dwim_ref(r, start_name, strlen(start_name), &oid,
 554                               &real_ref, 0)) {
 555         case 0:
 556                 /* Not branching from any existing branch */
 557                 if (explicit_tracking)
 558                         die(_(upstream_not_branch), start_name);
 559                 break;
 560         case 1:
 561                 /* Unique completion -- good, only if it is a real branch */
 562                 if (!starts_with(real_ref, "refs/heads/") &&
 563                     validate_remote_tracking_branch(real_ref)) {
 564                         if (explicit_tracking)
 565                                 die(_(upstream_not_branch), start_name);
 566                         else
 567                                 FREE_AND_NULL(real_ref);
 568                 }
 569                 break;
 570         default:
 571                 die(_("ambiguous object name: '%s'"), start_name);
 572                 break;
 573         }
 574
 575         if (!(commit = lookup_commit_reference(r, &oid)))
 576                 die(_("not a valid branch point: '%s'"), start_name);
 577         if (out_real_ref) {
 578                 *out_real_ref = real_ref;
 579                 real_ref = NULL;
 580         }
 581         if (out_oid)
 582                 oidcpy(out_oid, &commit->object.oid);
 583
 584         FREE_AND_NULL(real_ref);
 585 }
 586
 587 void create_branch(struct repository *r,
 588                    const char *name, const char *start_name,
 589                    int force, int clobber_head_ok, int reflog,
 590                    int quiet, enum branch_track track, int dry_run)
 591 {
 592         struct object_id oid;
 593         char *real_ref;
 594         struct strbuf ref = STRBUF_INIT;
 595         int forcing = 0;
 596         struct ref_transaction *transaction;
 597         struct strbuf err = STRBUF_INIT;
 598         char *msg;
 599
 600         if (track == BRANCH_TRACK_OVERRIDE)
 601                 BUG("'track' cannot be BRANCH_TRACK_OVERRIDE. Did you mean to call dwim_and_setup_tracking()?");
 602         if (clobber_head_ok && !force)
 603                 BUG("'clobber_head_ok' can only be used with 'force'");
 604
 605         if (clobber_head_ok ?
 606                           validate_branchname(name, &ref) :
 607                           validate_new_branchname(name, &ref, force)) {
 608                 forcing = 1;
 609         }
 610
 611         dwim_branch_start(r, start_name, track, &real_ref, &oid);
 612         if (dry_run)
 613                 goto cleanup;
 614
 615         if (reflog)
 616                 log_all_ref_updates = LOG_REFS_NORMAL;
 617
 618         if (forcing)
 619                 msg = xstrfmt("branch: Reset to %s", start_name);
 620         else
 621                 msg = xstrfmt("branch: Created from %s", start_name);
 622         transaction = ref_transaction_begin(&err);
 623         if (!transaction ||
 624                 ref_transaction_update(transaction, ref.buf,
 625                                         &oid, forcing ? NULL : null_oid(),
 626                                         0, msg, &err) ||
 627                 ref_transaction_commit(transaction, &err))
 628                 die("%s", err.buf);
 629         ref_transaction_free(transaction);
 630         strbuf_release(&err);
 631         free(msg);
 632
 633         if (real_ref && track)
 634                 setup_tracking(ref.buf + 11, real_ref, track, quiet);
 635
 636 cleanup:
 637         strbuf_release(&ref);
 638         free(real_ref);
 639 }
 640
 641 void dwim_and_setup_tracking(struct repository *r, const char *new_ref,
 642                              const char *orig_ref, enum branch_track track,
 643                              int quiet)
 644 {
 645         char *real_orig_ref = NULL;
 646         dwim_branch_start(r, orig_ref, track, &real_orig_ref, NULL);
 647         setup_tracking(new_ref, real_orig_ref, track, quiet);
 648         free(real_orig_ref);
 649 }
 650
 651 /**
 652  * Creates a branch in a submodule by calling
 653  * create_branches_recursively() in a child process. The child process
 654  * is necessary because install_branch_config_multiple_remotes() (which
 655  * is called by setup_tracking()) does not support writing configs to
 656  * submodules.
 657  */
 658 static int submodule_create_branch(struct repository *r,
 659                                    const struct submodule *submodule,
 660                                    const char *name, const char *start_oid,
 661                                    const char *tracking_name, int force,
 662                                    int reflog, int quiet,
 663                                    enum branch_track track, int dry_run)
 664 {
 665         int ret = 0;
 666         struct child_process child = CHILD_PROCESS_INIT;
 667         struct strbuf child_err = STRBUF_INIT;
 668         struct strbuf out_buf = STRBUF_INIT;
 669         char *out_prefix = xstrfmt("submodule '%s': ", submodule->name);
 670         child.git_cmd = 1;
 671         child.err = -1;
 672         child.stdout_to_stderr = 1;
 673
 674         prepare_other_repo_env(&child.env, r->gitdir);
 675         /*
 676          * submodule_create_branch() is indirectly invoked by "git
 677          * branch", but we cannot invoke "git branch" in the child
 678          * process. "git branch" accepts a branch name and start point,
 679          * where the start point is assumed to provide both the OID
 680          * (start_oid) and the branch to use for tracking
 681          * (tracking_name). But when recursing through submodules,
 682          * start_oid and tracking name need to be specified separately
 683          * (see create_branches_recursively()).
 684          */
 685         strvec_pushl(&child.args, "submodule--helper", "create-branch", NULL);
 686         if (dry_run)
 687                 strvec_push(&child.args, "--dry-run");
 688         if (force)
 689                 strvec_push(&child.args, "--force");
 690         if (quiet)
 691                 strvec_push(&child.args, "--quiet");
 692         if (reflog)
 693                 strvec_push(&child.args, "--create-reflog");
 694
 695         switch (track) {
 696         case BRANCH_TRACK_NEVER:
 697                 strvec_push(&child.args, "--no-track");
 698                 break;
 699         case BRANCH_TRACK_ALWAYS:
 700         case BRANCH_TRACK_EXPLICIT:
 701                 strvec_push(&child.args, "--track=direct");
 702                 break;
 703         case BRANCH_TRACK_OVERRIDE:
 704                 BUG("BRANCH_TRACK_OVERRIDE cannot be used when creating a branch.");
 705                 break;
 706         case BRANCH_TRACK_INHERIT:
 707                 strvec_push(&child.args, "--track=inherit");
 708                 break;
 709         case BRANCH_TRACK_UNSPECIFIED:
 710                 /* Default for "git checkout". Do not pass --track. */
 711         case BRANCH_TRACK_REMOTE:
 712                 /* Default for "git branch". Do not pass --track. */
 713         case BRANCH_TRACK_SIMPLE:
 714                 /* Config-driven only. Do not pass --track. */
 715                 break;
 716         }
 717
 718         strvec_pushl(&child.args, name, start_oid, tracking_name, NULL);
 719
 720         if ((ret = start_command(&child)))
 721                 return ret;
 722         ret = finish_command(&child);
 723         strbuf_read(&child_err, child.err, 0);
 724         strbuf_add_lines(&out_buf, out_prefix, child_err.buf, child_err.len);
 725
 726         if (ret)
 727                 fprintf(stderr, "%s", out_buf.buf);
 728         else
 729                 printf("%s", out_buf.buf);
 730
 731         strbuf_release(&child_err);
 732         strbuf_release(&out_buf);
 733         return ret;
 734 }
 735
 736 void create_branches_recursively(struct repository *r, const char *name,
 737                                  const char *start_commitish,
 738                                  const char *tracking_name, int force,
 739                                  int reflog, int quiet, enum branch_track track,
 740                                  int dry_run)
 741 {
 742         int i = 0;
 743         char *branch_point = NULL;
 744         struct object_id super_oid;
 745         struct submodule_entry_list submodule_entry_list;
 746
 747         /* Perform dwim on start_commitish to get super_oid and branch_point. */
 748         dwim_branch_start(r, start_commitish, BRANCH_TRACK_NEVER,
 749                           &branch_point, &super_oid);
 750
 751         /*
 752          * If we were not given an explicit name to track, then assume we are at
 753          * the top level and, just like the non-recursive case, the tracking
 754          * name is the branch point.
 755          */
 756         if (!tracking_name)
 757                 tracking_name = branch_point;
 758
 759         submodules_of_tree(r, &super_oid, &submodule_entry_list);
 760         /*
 761          * Before creating any branches, first check that the branch can
 762          * be created in every submodule.
 763          */
 764         for (i = 0; i < submodule_entry_list.entry_nr; i++) {
 765                 if (!submodule_entry_list.entries[i].repo) {
 766                         int code = die_message(
 767                                 _("submodule '%s': unable to find submodule"),
 768                                 submodule_entry_list.entries[i].submodule->name);
 769                         if (advice_enabled(ADVICE_SUBMODULES_NOT_UPDATED))
 770                                 advise(_("You may try updating the submodules using 'git checkout --no-recurse-submodules %s && git submodule update --init'"),
 771                                        start_commitish);
 772                         exit(code);
 773                 }
 774
 775                 if (submodule_create_branch(
 776                             submodule_entry_list.entries[i].repo,
 777                             submodule_entry_list.entries[i].submodule, name,
 778                             oid_to_hex(&submodule_entry_list.entries[i]
 779                                                 .name_entry->oid),
 780                             tracking_name, force, reflog, quiet, track, 1))
 781                         die(_("submodule '%s': cannot create branch '%s'"),
 782                             submodule_entry_list.entries[i].submodule->name,
 783                             name);
 784         }
 785
 786         create_branch(r, name, start_commitish, force, 0, reflog, quiet,
 787                       BRANCH_TRACK_NEVER, dry_run);
 788         if (dry_run)
 789                 return;
 790         /*
 791          * NEEDSWORK If tracking was set up in the superproject but not the
 792          * submodule, users might expect "git branch --recurse-submodules" to
 793          * fail or give a warning, but this is not yet implemented because it is
 794          * tedious to determine whether or not tracking was set up in the
 795          * superproject.
 796          */
 797         if (track)
 798                 setup_tracking(name, tracking_name, track, quiet);
 799
 800         for (i = 0; i < submodule_entry_list.entry_nr; i++) {
 801                 if (submodule_create_branch(
 802                             submodule_entry_list.entries[i].repo,
 803                             submodule_entry_list.entries[i].submodule, name,
 804                             oid_to_hex(&submodule_entry_list.entries[i]
 805                                                 .name_entry->oid),
 806                             tracking_name, force, reflog, quiet, track, 0))
 807                         die(_("submodule '%s': cannot create branch '%s'"),
 808                             submodule_entry_list.entries[i].submodule->name,
 809                             name);
 810                 repo_clear(submodule_entry_list.entries[i].repo);
 811         }
 812 }
 813
 814 void remove_merge_branch_state(struct repository *r)
 815 {
 816         unlink(git_path_merge_head(r));
 817         unlink(git_path_merge_rr(r));
 818         unlink(git_path_merge_msg(r));
 819         unlink(git_path_merge_mode(r));
 820         refs_delete_ref(get_main_ref_store(r), "", "AUTO_MERGE",
 821                         NULL, REF_NO_DEREF);
 822         save_autostash_ref(r, "MERGE_AUTOSTASH");
 823 }
 824
 825 void remove_branch_state(struct repository *r, int verbose)
 826 {
 827         sequencer_post_commit_cleanup(r, verbose);
 828         unlink(git_path_squash_msg(r));
 829         remove_merge_branch_state(r);
 830 }
 831
 832 void die_if_checked_out(const char *branch, int ignore_current_worktree)
 833 {
 834         struct worktree **worktrees = get_worktrees();
 835
 836         for (int i = 0; worktrees[i]; i++) {
 837                 if (worktrees[i]->is_current && ignore_current_worktree)
 838                         continue;
 839
 840                 if (is_shared_symref(worktrees[i], "HEAD", branch)) {
 841                         skip_prefix(branch, "refs/heads/", &branch);
 842                         die(_("'%s' is already used by worktree at '%s'"),
 843                                 branch, worktrees[i]->path);
 844                 }
 845         }
 846
 847         free_worktrees(worktrees);
 848 }