New lightweight Carp has a require. If Carp is used in a __DIE__ handler

this causes a POPSTACK panic. The problem seems to be that although
die_where() has unwound the tail of perl_vdie() top_env setjmp has been
set to resume execution there. Avoiding setting CATCH_SET(TRUE) in 
call_sv() avoids this. So invent a new G_NOCATCH flag to disable
messing with CATCH_SET() in call_sv, use it in perl_vdie().
Add test to op/eval.t which will fail (panic) if bug comes back.
>>> I AM NOT CONVINCED THIS IS CORRECT LONG TERM FIX <<<

p4raw-id: //depot/perl@3988

1 files changed, 5 insertions, 1 deletions

diff --git a/util.c b/util.c
index 132ec5e127..715a5f1a15 100644
--- a/util.c
+++ b/util.c
@@ -1491,7 +1491,11 @@ Perl_vdie(pTHX_ const char* pat, va_list *args)
 	    PUSHMARK(SP);
 	    XPUSHs(msg);
 	    PUTBACK;
-	    call_sv((SV*)cv, G_DISCARD);
+	    /* HACK - REVISIT - avoid CATCH_SET(TRUE) in call_sv()
+	       or we come back here due to a JMPENV_JMP() and do 
+	       a POPSTACK - but die_where() will have already done 
+	       one as it unwound - NI-S 1999/08/14 */
+	    call_sv((SV*)cv, G_DISCARD|G_NOCATCH);
 	    POPSTACK;
 	    LEAVE;
 	}