don't rely on ghost contexts being unmolested

Dying and returning from a format both relied on the state of a
just-popped context frame being preserved across a LEAVE.  Don't rely
on it.  Test using an operator ripped off from Scope::Cleanup, which makes
it easy to run arbitrary Perl code during cleanup, without isolating it
on a separate context stack as the DESTROY mechanism does.

1 files changed, 3 insertions, 1 deletions

diff --git a/pp_sys.c b/pp_sys.c
index 39daad6880..78b635f05d 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -1348,6 +1348,7 @@ PP(pp_leavewrite)
     SV **newsp;
     I32 gimme;
     register PERL_CONTEXT *cx;
+    OP *retop;
 
     if (!io || !(ofp = IoOFP(io)))
         goto forget_top;
@@ -1428,6 +1429,7 @@ PP(pp_leavewrite)
   forget_top:
     POPBLOCK(cx,PL_curpm);
     POPFORMAT(cx);
+    retop = cx->blk_sub.retop;
     LEAVE;
 
     fp = IoOFP(io);
@@ -1460,7 +1462,7 @@ PP(pp_leavewrite)
     PUTBACK;
     PERL_UNUSED_VAR(newsp);
     PERL_UNUSED_VAR(gimme);
-    return cx->blk_sub.retop;
+    return retop;
 }
 
 PP(pp_prtf)