reset.c

   1 #include "git-compat-util.h"
   2 #include "cache-tree.h"
   3 #include "hex.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "reset.h"
   7 #include "run-command.h"
   8 #include "tree-walk.h"
   9 #include "tree.h"
  10 #include "unpack-trees.h"
  11 #include "hook.h"
  12
  13 static int update_refs(const struct reset_head_opts *opts,
  14                        const struct object_id *oid,
  15                        const struct object_id *head)
  16 {
  17         unsigned detach_head = opts->flags & RESET_HEAD_DETACH;
  18         unsigned run_hook = opts->flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
  19         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  20         const struct object_id *orig_head = opts->orig_head;
  21         const char *switch_to_branch = opts->branch;
  22         const char *reflog_branch = opts->branch_msg;
  23         const char *reflog_head = opts->head_msg;
  24         const char *reflog_orig_head = opts->orig_head_msg;
  25         const char *default_reflog_action = opts->default_reflog_action;
  26         struct object_id *old_orig = NULL, oid_old_orig;
  27         struct strbuf msg = STRBUF_INIT;
  28         const char *reflog_action;
  29         size_t prefix_len;
  30         int ret;
  31
  32         if ((update_orig_head && !reflog_orig_head) || !reflog_head) {
  33                 if (!default_reflog_action)
  34                         BUG("default_reflog_action must be given when reflog messages are omitted");
  35                 reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
  36                 strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action :
  37                                                           default_reflog_action);
  38         }
  39         prefix_len = msg.len;
  40
  41         if (update_orig_head) {
  42                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
  43                         old_orig = &oid_old_orig;
  44                 if (head) {
  45                         if (!reflog_orig_head) {
  46                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
  47                                 reflog_orig_head = msg.buf;
  48                         }
  49                         update_ref(reflog_orig_head, "ORIG_HEAD",
  50                                    orig_head ? orig_head : head,
  51                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
  52                 } else if (old_orig)
  53                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
  54         }
  55
  56         if (!reflog_head) {
  57                 strbuf_setlen(&msg, prefix_len);
  58                 strbuf_addstr(&msg, "updating HEAD");
  59                 reflog_head = msg.buf;
  60         }
  61         if (!switch_to_branch)
  62                 ret = update_ref(reflog_head, "HEAD", oid, head,
  63                                  detach_head ? REF_NO_DEREF : 0,
  64                                  UPDATE_REFS_MSG_ON_ERR);
  65         else {
  66                 ret = update_ref(reflog_branch ? reflog_branch : reflog_head,
  67                                  switch_to_branch, oid, NULL, 0,
  68                                  UPDATE_REFS_MSG_ON_ERR);
  69                 if (!ret)
  70                         ret = create_symref("HEAD", switch_to_branch,
  71                                             reflog_head);
  72         }
  73         if (!ret && run_hook)
  74                 run_hooks_l("post-checkout",
  75                             oid_to_hex(head ? head : null_oid()),
  76                             oid_to_hex(oid), "1", NULL);
  77         strbuf_release(&msg);
  78         return ret;
  79 }
  80
  81 int reset_head(struct repository *r, const struct reset_head_opts *opts)
  82 {
  83         const struct object_id *oid = opts->oid;
  84         const char *switch_to_branch = opts->branch;
  85         unsigned reset_hard = opts->flags & RESET_HEAD_HARD;
  86         unsigned refs_only = opts->flags & RESET_HEAD_REFS_ONLY;
  87         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  88         struct object_id *head = NULL, head_oid;
  89         struct tree_desc desc[2] = { { NULL }, { NULL } };
  90         struct lock_file lock = LOCK_INIT;
  91         struct unpack_trees_options unpack_tree_opts = { 0 };
  92         struct tree *tree;
  93         const char *action;
  94         int ret = 0, nr = 0;
  95
  96         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
  97                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
  98
  99         if (opts->orig_head_msg && !update_orig_head)
 100                 BUG("ORIG_HEAD reflog message given without updating ORIG_HEAD");
 101
 102         if (opts->branch_msg && !opts->branch)
 103                 BUG("branch reflog message given without a branch");
 104
 105         if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
 106                 ret = -1;
 107                 goto leave_reset_head;
 108         }
 109
 110         if (!get_oid("HEAD", &head_oid)) {
 111                 head = &head_oid;
 112         } else if (!oid || !reset_hard) {
 113                 ret = error(_("could not determine HEAD revision"));
 114                 goto leave_reset_head;
 115         }
 116
 117         if (!oid)
 118                 oid = &head_oid;
 119
 120         if (refs_only)
 121                 return update_refs(opts, oid, head);
 122
 123         action = reset_hard ? "reset" : "checkout";
 124         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 125         unpack_tree_opts.head_idx = 1;
 126         unpack_tree_opts.src_index = r->index;
 127         unpack_tree_opts.dst_index = r->index;
 128         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 129         unpack_tree_opts.update = 1;
 130         unpack_tree_opts.merge = 1;
 131         unpack_tree_opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
 132         unpack_tree_opts.skip_cache_tree_update = 1;
 133         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 134         if (reset_hard)
 135                 unpack_tree_opts.reset = UNPACK_RESET_PROTECT_UNTRACKED;
 136
 137         if (repo_read_index_unmerged(r) < 0) {
 138                 ret = error(_("could not read index"));
 139                 goto leave_reset_head;
 140         }
 141
 142         if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
 143                 ret = error(_("failed to find tree of %s"),
 144                             oid_to_hex(&head_oid));
 145                 goto leave_reset_head;
 146         }
 147
 148         if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
 149                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 150                 goto leave_reset_head;
 151         }
 152
 153         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 154                 ret = -1;
 155                 goto leave_reset_head;
 156         }
 157
 158         tree = parse_tree_indirect(oid);
 159         prime_cache_tree(r, r->index, tree);
 160
 161         if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
 162                 ret = error(_("could not write index"));
 163                 goto leave_reset_head;
 164         }
 165
 166         if (oid != &head_oid || update_orig_head || switch_to_branch)
 167                 ret = update_refs(opts, oid, head);
 168
 169 leave_reset_head:
 170         rollback_lock_file(&lock);
 171         clear_unpack_trees_porcelain(&unpack_tree_opts);
 172         while (nr)
 173                 free((void *)desc[--nr].buffer);
 174         return ret;
 175
 176 }