make ~$x give warning is $x isn't initialised.

Also add test for uninitialised warning in & op.

p4raw-id: //depot/perl@22525

1 files changed, 1 insertions, 0 deletions

diff --git a/pp.c b/pp.c
index 8b485fda1f..866d55459e 100644
--- a/pp.c
+++ b/pp.c
@@ -2377,6 +2377,7 @@ PP(pp_complement)
 	register I32 anum;
 	STRLEN len;
 
+	(void)SvPV_nomg(sv,len);
 	sv_setsv_nomg(TARG, sv);
 	tmps = (U8*)SvPV_force(TARG, len);
 	anum = len;