branch: restrict @-expansions when deleting

We use strbuf_branchname() to expand the branch name from
the command line, so you can delete the branch given by
@{-1}, for example.  However, we allow other nonsense like
"@", and we do not respect our "-r" flag (so we may end up
deleting an oddly-named local ref instead of a remote one).

We can fix this by passing the appropriate "allowed" flag to
strbuf_branchname().

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

builtin/branch.c

@@ -190,17 +190,20 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 	int ret = 0;
 	int remote_branch = 0;
 	struct strbuf bname = STRBUF_INIT;
+	unsigned allowed_interpret;
 
 	switch (kinds) {
 	case FILTER_REFS_REMOTES:
 		fmt = "refs/remotes/%s";
 		/* For subsequent UI messages */
 		remote_branch = 1;
+		allowed_interpret = INTERPRET_BRANCH_REMOTE;
 
 		force = 1;
 		break;
 	case FILTER_REFS_BRANCHES:
 		fmt = "refs/heads/%s";
+		allowed_interpret = INTERPRET_BRANCH_LOCAL;
 		break;
 	default:
 		die(_("cannot use -a with -d"));
@@ -215,7 +218,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 		char *target = NULL;
 		int flags = 0;
 
-		strbuf_branchname(&bname, argv[i], 0);
+		strbuf_branchname(&bname, argv[i], allowed_interpret);
 		free(name);
 		name = mkpathdup(fmt, bname.buf);
 

t/t3204-branch-name-interpretation.sh

@@ -83,7 +83,7 @@ test_expect_success 'delete branch via remote @{upstream}' '
 # Note that we create two oddly named local branches here. We want to make
 # sure that we do not accidentally delete either of them, even if
 # shorten_unambiguous_ref() tweaks the name to avoid ambiguity.
-test_expect_failure 'delete @{upstream} expansion matches -r option' '
+test_expect_success 'delete @{upstream} expansion matches -r option' '
 	git update-ref refs/remotes/origin/remote-del two &&
 	git branch --set-upstream-to=origin/remote-del &&
 	git update-ref refs/heads/origin/remote-del two &&
@@ -94,7 +94,7 @@ test_expect_failure 'delete @{upstream} expansion matches -r option' '
 	expect_branch refs/heads/remotes/origin/remote-del two
 '
 
-test_expect_failure 'disallow deleting remote branch via @{-1}' '
+test_expect_success 'disallow deleting remote branch via @{-1}' '
 	git update-ref refs/remotes/origin/previous one &&
 
 	git checkout -b origin/previous two &&
@@ -114,7 +114,7 @@ test_expect_failure 'create branch named "@"' '
 	expect_branch refs/heads/@ one
 '
 
-test_expect_failure 'delete branch named "@"' '
+test_expect_success 'delete branch named "@"' '
 	git update-ref refs/heads/@ two &&
 	git branch -D @ &&
 	expect_deleted refs/heads/@