clone: factor out checkout code

Read HEAD from disk instead of relying on local variable
our_head_points_at, so that if earlier code fails to make HEAD
properly, it'll be detected.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index 91862f79636b4b85d061a313b3566b01b06d6753..98e354242b7eaa38ecbe86f3913a5d55037f60a4 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -486,6 +486,63 @@ static void write_followtags(const struct ref *refs, const char *msg)
        }
 }
 
+static int checkout(void)
+{
+       unsigned char sha1[20];
+       char *head;
+       struct lock_file *lock_file;
+       struct unpack_trees_options opts;
+       struct tree *tree;
+       struct tree_desc t;
+       int err = 0, fd;
+
+       if (option_no_checkout)
+               return 0;
+
+       head = resolve_refdup("HEAD", sha1, 1, NULL);
+       if (!head) {
+               warning(_("remote HEAD refers to nonexistent ref, "
+                         "unable to checkout.\n"));
+               return 0;
+       }
+       if (strcmp(head, "HEAD")) {
+               if (prefixcmp(head, "refs/heads/"))
+                       die(_("HEAD not found below refs/heads!"));
+       }
+       free(head);
+
+       /* We need to be in the new work tree for the checkout */
+       setup_work_tree();
+
+       lock_file = xcalloc(1, sizeof(struct lock_file));
+       fd = hold_locked_index(lock_file, 1);
+
+       memset(&opts, 0, sizeof opts);
+       opts.update = 1;
+       opts.merge = 1;
+       opts.fn = oneway_merge;
+       opts.verbose_update = (option_verbosity > 0);
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
+
+       tree = parse_tree_indirect(sha1);
+       parse_tree(tree);
+       init_tree_desc(&t, tree->buffer, tree->size);
+       unpack_trees(1, &t, &opts);
+
+       if (write_cache(fd, active_cache, active_nr) ||
+           commit_locked_index(lock_file))
+               die(_("unable to write new index file"));
+
+       err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
+                       sha1_to_hex(sha1), "1", NULL);
+
+       if (!err && option_recursive)
+               err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
+
+       return err;
+}
+
 static int write_one_config(const char *key, const char *value, void *data)
 {
        return git_config_set_multivar(key, value ? value : "true", "^$", 0);
@@ -766,13 +823,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
                /* Source had detached HEAD pointing somewhere. */
                update_ref(reflog_msg.buf, "HEAD", remote_head->old_sha1,
                           NULL, REF_NODEREF, DIE_ON_ERR);
-               our_head_points_at = remote_head;
-       } else {
-               /* Nothing to checkout out */
-               if (!option_no_checkout)
-                       warning(_("remote HEAD refers to nonexistent ref, "
-                               "unable to checkout.\n"));
-               option_no_checkout = 1;
        }
 
        if (transport) {
@@ -780,42 +830,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
                transport_disconnect(transport);
        }
 
-       if (!option_no_checkout) {
-               struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
-               struct unpack_trees_options opts;
-               struct tree *tree;
-               struct tree_desc t;
-               int fd;
-
-               /* We need to be in the new work tree for the checkout */
-               setup_work_tree();
-
-               fd = hold_locked_index(lock_file, 1);
-
-               memset(&opts, 0, sizeof opts);
-               opts.update = 1;
-               opts.merge = 1;
-               opts.fn = oneway_merge;
-               opts.verbose_update = (option_verbosity > 0);
-               opts.src_index = &the_index;
-               opts.dst_index = &the_index;
-
-               tree = parse_tree_indirect(our_head_points_at->old_sha1);
-               parse_tree(tree);
-               init_tree_desc(&t, tree->buffer, tree->size);
-               unpack_trees(1, &t, &opts);
-
-               if (write_cache(fd, active_cache, active_nr) ||
-                   commit_locked_index(lock_file))
-                       die(_("unable to write new index file"));
-
-               err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
-                               sha1_to_hex(our_head_points_at->old_sha1), "1",
-                               NULL);
-
-               if (!err && option_recursive)
-                       err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
-       }
+       err = checkout();
 
        strbuf_release(&reflog_msg);
        strbuf_release(&branch_top);