X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=builtin-checkout.c;h=c107fd643a452edb016f7ad867d4b2a555d9abaf;hb=16d258332e35dad58c0b22cd4d5c0e63ebb25328;hp=c4fc2b2c562725018789dead3b86ccfbc4e2925f;hpb=edb7e82f72106add9f2fbaf9d99d9532a72e3f91;p=git.git

diff --git a/builtin-checkout.c b/builtin-checkout.c
index c4fc2b2c5..c107fd643 100644
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -32,7 +32,7 @@ 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;
@@ -269,8 +269,7 @@ 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;
@@ -360,10 +359,10 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 
 	strbuf_init(&msg, 0);
 	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);
@@ -419,10 +418,10 @@ 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);
@@ -565,6 +564,18 @@ no_reference:
 		return checkout_paths(source_tree, pathspec);
 	}
 
+	if (opts.new_branch) {
+		struct strbuf buf;
+		strbuf_init(&buf, 0);
+		strbuf_addstr(&buf, "refs/heads/");
+		strbuf_addstr(&buf, opts.new_branch);
+		if (!get_sha1(buf.buf, rev))
+			die("git checkout: branch %s already exists", opts.new_branch);
+		if (check_ref_format(buf.buf))
+			die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
+		strbuf_release(&buf);
+	}
+
 	if (new.name && !new.commit) {
 		die("Cannot switch branch to a non-commit.");
 	}