make local @tied, %tied, untied

Fix for RT #7938, #7939: when localising an array or hash, don't make the
new aggregate tied.

The old behaviour of { local @tied; ... } was equivalent to:

    {
	my $saved = \@tied;
	*tied = [];
	tied(@tied) = tied(@$saved)  # if tied() were an lvalue function
	...
	*tied = $saved;
    }

This patch simply removes the 'tied(@tied) = ...' step

1 files changed, 1 insertions, 0 deletions

diff --git a/mg.c b/mg.c
index 4be1b3c2e1..ccb5b82117 100644
--- a/mg.c
+++ b/mg.c
@@ -178,6 +178,7 @@ S_is_container_magic(const MAGIC *mg)
     case PERL_MAGIC_arylen_p:
     case PERL_MAGIC_rhash:
     case PERL_MAGIC_symtab:
+    case PERL_MAGIC_tied: /* treat as value, so 'local @tied' isn't tied */
 	return 0;
     default:
 	return 1;