X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=builtin-checkout.c;h=c2c05613b67d7cc8bd3500bdbca4fc3533afaeee;hb=cec08717cca468c66eb454c7201fd35f54b48a58;hp=57b94d282931187a0cb6394d4df707237038a7eb;hpb=a157400c972bbdeab2b5629658c99839c855f5ab;p=git.git

diff --git a/builtin-checkout.c b/builtin-checkout.c
index 57b94d282..c2c05613b 100644
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -47,7 +47,7 @@ static int post_checkout_hook(struct commit *old, struct commit *new,
 
 	memset(&proc, 0, sizeof(proc));
 	argv[0] = name;
-	argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
+	argv[1] = xstrdup(sha1_to_hex(old ? old->object.sha1 : null_sha1));
 	argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
 	argv[3] = changed ? "1" : "0";
 	argv[4] = NULL;
@@ -228,7 +228,8 @@ static int checkout_paths(struct tree *source_tree, const char **pathspec,
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 
 	newfd = hold_locked_index(lock_file, 1);
-	read_cache();
+	if (read_cache() < 0)
+		return error("corrupt index file");
 
 	if (source_tree)
 		read_tree_some(source_tree, pathspec);
@@ -371,7 +372,9 @@ static int merge_working_tree(struct checkout_opts *opts,
 	int ret;
 	struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 	int newfd = hold_locked_index(lock_file, 1);
-	read_cache();
+
+	if (read_cache() < 0)
+		return error("corrupt index file");
 
 	if (opts->force) {
 		ret = reset_tree(new->commit->tree, opts, 1);
@@ -397,8 +400,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		}
 
 		/* 2-way merge to the new branch */
-		topts.initial_checkout = (!active_nr &&
-					  (old->commit == new->commit));
+		topts.initial_checkout = is_cache_unborn();
 		topts.update = 1;
 		topts.merge = 1;
 		topts.gently = opts->merge;
@@ -492,10 +494,10 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 	}
 
 	old_desc = old->name;
-	if (!old_desc)
+	if (!old_desc && old->commit)
 		old_desc = sha1_to_hex(old->commit->object.sha1);
 	strbuf_addf(&msg, "checkout: moving from %s to %s",
-		    old_desc, new->name);
+		    old_desc ? old_desc : "(invalid)", new->name);
 
 	if (new->path) {
 		create_symref("HEAD", new->path, msg.buf);
@@ -551,10 +553,10 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 	 * a new commit, we want to mention the old commit once more
 	 * to remind the user that it might be lost.
 	 */
-	if (!opts->quiet && !old.path && new->commit != old.commit)
+	if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
 		describe_detached_head("Previous HEAD position was", old.commit);
 
-	if (!old.commit) {
+	if (!old.commit && !opts->force) {
 		if (!opts->quiet) {
 			fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
 			fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);