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 int reset_head(struct repository *r, struct object_id *oid, const char *action,
  12                const char *switch_to_branch, unsigned flags,
  13                const char *reflog_orig_head, const char *reflog_head,
  14                const char *default_reflog_action)
  15 {
  16         unsigned detach_head = flags & RESET_HEAD_DETACH;
  17         unsigned reset_hard = flags & RESET_HEAD_HARD;
  18         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
  19         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
  20         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
  21         struct object_id head_oid;
  22         struct tree_desc desc[2] = { { NULL }, { NULL } };
  23         struct lock_file lock = LOCK_INIT;
  24         struct unpack_trees_options unpack_tree_opts;
  25         struct tree *tree;
  26         const char *reflog_action;
  27         struct strbuf msg = STRBUF_INIT;
  28         size_t prefix_len;
  29         struct object_id *orig = NULL, oid_orig,
  30                 *old_orig = NULL, oid_old_orig;
  31         int ret = 0, nr = 0;
  32
  33         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
  34                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
  35
  36         if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
  37                 ret = -1;
  38                 goto leave_reset_head;
  39         }
  40
  41         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
  42                 ret = error(_("could not determine HEAD revision"));
  43                 goto leave_reset_head;
  44         }
  45
  46         if (!oid)
  47                 oid = &head_oid;
  48
  49         if (refs_only)
  50                 goto reset_head_refs;
  51
  52         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
  53         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
  54         unpack_tree_opts.head_idx = 1;
  55         unpack_tree_opts.src_index = r->index;
  56         unpack_tree_opts.dst_index = r->index;
  57         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
  58         unpack_tree_opts.update = 1;
  59         unpack_tree_opts.merge = 1;
  60         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
  61         if (!detach_head)
  62                 unpack_tree_opts.reset = 1;
  63
  64         if (repo_read_index_unmerged(r) < 0) {
  65                 ret = error(_("could not read index"));
  66                 goto leave_reset_head;
  67         }
  68
  69         if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
  70                 ret = error(_("failed to find tree of %s"),
  71                             oid_to_hex(&head_oid));
  72                 goto leave_reset_head;
  73         }
  74
  75         if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
  76                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
  77                 goto leave_reset_head;
  78         }
  79
  80         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
  81                 ret = -1;
  82                 goto leave_reset_head;
  83         }
  84
  85         tree = parse_tree_indirect(oid);
  86         prime_cache_tree(r, r->index, tree);
  87
  88         if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
  89                 ret = error(_("could not write index"));
  90                 goto leave_reset_head;
  91         }
  92
  93 reset_head_refs:
  94         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
  95         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
  96         prefix_len = msg.len;
  97
  98         if (update_orig_head) {
  99                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
 100                         old_orig = &oid_old_orig;
 101                 if (!get_oid("HEAD", &oid_orig)) {
 102                         orig = &oid_orig;
 103                         if (!reflog_orig_head) {
 104                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 105                                 reflog_orig_head = msg.buf;
 106                         }
 107                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
 108                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
 109                 } else if (old_orig)
 110                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 111         }
 112
 113         if (!reflog_head) {
 114                 strbuf_setlen(&msg, prefix_len);
 115                 strbuf_addstr(&msg, "updating HEAD");
 116                 reflog_head = msg.buf;
 117         }
 118         if (!switch_to_branch)
 119                 ret = update_ref(reflog_head, "HEAD", oid, orig,
 120                                  detach_head ? REF_NO_DEREF : 0,
 121                                  UPDATE_REFS_MSG_ON_ERR);
 122         else {
 123                 ret = update_ref(reflog_head, switch_to_branch, oid,
 124                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 125                 if (!ret)
 126                         ret = create_symref("HEAD", switch_to_branch,
 127                                             reflog_head);
 128         }
 129         if (run_hook)
 130                 run_hook_le(NULL, "post-checkout",
 131                             oid_to_hex(orig ? orig : &null_oid),
 132                             oid_to_hex(oid), "1", NULL);
 133
 134 leave_reset_head:
 135         strbuf_release(&msg);
 136         rollback_lock_file(&lock);
 137         while (nr)
 138                 free((void *)desc[--nr].buffer);
 139         return ret;
 140
 141 }