reset.c

   1 #include "git-compat-util.h"
   2 #include "cache-tree.h"
   3 #include "gettext.h"
   4 #include "hex.h"
   5 #include "lockfile.h"
   6 #include "object-name.h"
   7 #include "refs.h"
   8 #include "reset.h"
   9 #include "tree-walk.h"
  10 #include "tree.h"
  11 #include "unpack-trees.h"
  12 #include "hook.h"
  13
  14 static int update_refs(const struct reset_head_opts *opts,
  15                        const struct object_id *oid,
  16                        const struct object_id *head)
  17 {
  18         unsigned detach_head = opts->flags & RESET_HEAD_DETACH;
  19         unsigned run_hook = opts->flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
  20         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  21         const struct object_id *orig_head = opts->orig_head;
  22         const char *switch_to_branch = opts->branch;
  23         const char *reflog_branch = opts->branch_msg;
  24         const char *reflog_head = opts->head_msg;
  25         const char *reflog_orig_head = opts->orig_head_msg;
  26         const char *default_reflog_action = opts->default_reflog_action;
  27         struct object_id *old_orig = NULL, oid_old_orig;
  28         struct strbuf msg = STRBUF_INIT;
  29         const char *reflog_action;
  30         size_t prefix_len;
  31         int ret;
  32
  33         if ((update_orig_head && !reflog_orig_head) || !reflog_head) {
  34                 if (!default_reflog_action)
  35                         BUG("default_reflog_action must be given when reflog messages are omitted");
  36                 reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
  37                 strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action :
  38                                                           default_reflog_action);
  39         }
  40         prefix_len = msg.len;
  41
  42         if (update_orig_head) {
  43                 if (!repo_get_oid(the_repository, "ORIG_HEAD", &oid_old_orig))
  44                         old_orig = &oid_old_orig;
  45                 if (head) {
  46                         if (!reflog_orig_head) {
  47                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
  48                                 reflog_orig_head = msg.buf;
  49                         }
  50                         update_ref(reflog_orig_head, "ORIG_HEAD",
  51                                    orig_head ? orig_head : head,
  52                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
  53                 } else if (old_orig)
  54                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
  55         }
  56
  57         if (!reflog_head) {
  58                 strbuf_setlen(&msg, prefix_len);
  59                 strbuf_addstr(&msg, "updating HEAD");
  60                 reflog_head = msg.buf;
  61         }
  62         if (!switch_to_branch)
  63                 ret = update_ref(reflog_head, "HEAD", oid, head,
  64                                  detach_head ? REF_NO_DEREF : 0,
  65                                  UPDATE_REFS_MSG_ON_ERR);
  66         else {
  67                 ret = update_ref(reflog_branch ? reflog_branch : reflog_head,
  68                                  switch_to_branch, oid, NULL, 0,
  69                                  UPDATE_REFS_MSG_ON_ERR);
  70                 if (!ret)
  71                         ret = create_symref("HEAD", switch_to_branch,
  72                                             reflog_head);
  73         }
  74         if (!ret && run_hook)
  75                 run_hooks_l("post-checkout",
  76                             oid_to_hex(head ? head : null_oid()),
  77                             oid_to_hex(oid), "1", NULL);
  78         strbuf_release(&msg);
  79         return ret;
  80 }
  81
  82 int reset_head(struct repository *r, const struct reset_head_opts *opts)
  83 {
  84         const struct object_id *oid = opts->oid;
  85         const char *switch_to_branch = opts->branch;
  86         unsigned reset_hard = opts->flags & RESET_HEAD_HARD;
  87         unsigned refs_only = opts->flags & RESET_HEAD_REFS_ONLY;
  88         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  89         struct object_id *head = NULL, head_oid;
  90         struct tree_desc desc[2] = { { NULL }, { NULL } };
  91         struct lock_file lock = LOCK_INIT;
  92         struct unpack_trees_options unpack_tree_opts = { 0 };
  93         struct tree *tree;
  94         const char *action;
  95         int ret = 0, nr = 0;
  96
  97         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
  98                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
  99
 100         if (opts->orig_head_msg && !update_orig_head)
 101                 BUG("ORIG_HEAD reflog message given without updating ORIG_HEAD");
 102
 103         if (opts->branch_msg && !opts->branch)
 104                 BUG("branch reflog message given without a branch");
 105
 106         if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
 107                 ret = -1;
 108                 goto leave_reset_head;
 109         }
 110
 111         if (!repo_get_oid(r, "HEAD", &head_oid)) {
 112                 head = &head_oid;
 113         } else if (!oid || !reset_hard) {
 114                 ret = error(_("could not determine HEAD revision"));
 115                 goto leave_reset_head;
 116         }
 117
 118         if (!oid)
 119                 oid = &head_oid;
 120
 121         if (refs_only)
 122                 return update_refs(opts, oid, head);
 123
 124         action = reset_hard ? "reset" : "checkout";
 125         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 126         unpack_tree_opts.head_idx = 1;
 127         unpack_tree_opts.src_index = r->index;
 128         unpack_tree_opts.dst_index = r->index;
 129         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 130         unpack_tree_opts.update = 1;
 131         unpack_tree_opts.merge = 1;
 132         unpack_tree_opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
 133         unpack_tree_opts.skip_cache_tree_update = 1;
 134         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 135         if (reset_hard)
 136                 unpack_tree_opts.reset = UNPACK_RESET_PROTECT_UNTRACKED;
 137
 138         if (repo_read_index_unmerged(r) < 0) {
 139                 ret = error(_("could not read index"));
 140                 goto leave_reset_head;
 141         }
 142
 143         if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
 144                 ret = error(_("failed to find tree of %s"),
 145                             oid_to_hex(&head_oid));
 146                 goto leave_reset_head;
 147         }
 148
 149         if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
 150                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 151                 goto leave_reset_head;
 152         }
 153
 154         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 155                 ret = -1;
 156                 goto leave_reset_head;
 157         }
 158
 159         tree = parse_tree_indirect(oid);
 160         if (!tree) {
 161                 ret = error(_("unable to read tree (%s)"), oid_to_hex(oid));
 162                 goto leave_reset_head;
 163         }
 164
 165         prime_cache_tree(r, r->index, tree);
 166
 167         if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
 168                 ret = error(_("could not write index"));
 169                 goto leave_reset_head;
 170         }
 171
 172         if (oid != &head_oid || update_orig_head || switch_to_branch)
 173                 ret = update_refs(opts, oid, head);
 174
 175 leave_reset_head:
 176         rollback_lock_file(&lock);
 177         clear_unpack_trees_porcelain(&unpack_tree_opts);
 178         while (nr)
 179                 free((void *)desc[--nr].buffer);
 180         return ret;
 181
 182 }