Fixes obscure bug that manifests itself by.

local $!=0;undef*STDOUT;#segfaults
Has been around for a while. Possible other magic IO vars are
possibly affected as well. Reported by Jos Boumans.

p4raw-id: //depot/perl@12303

1 files changed, 2 insertions, 0 deletions

diff --git a/mg.c b/mg.c
index 4fc2ffc9f6..0fb1a86d5e 100644
--- a/mg.c
+++ b/mg.c
@@ -1894,6 +1894,8 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case '|':
 	{
 	    IO *io = GvIOp(PL_defoutgv);
+	    if(!io)
+	      break;
 	    if ((SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) == 0)
 		IoFLAGS(io) &= ~IOf_FLUSH;
 	    else {