reset.c

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