Feeding illegal QP (like \x80) to this

./perl -Ilib -wne 'use PerlIO::via::QuotedPrint;BEGIN{binmode(STDIN, ":via(QuotedPrint)")};print'
caused a coredump in av_length() <- nextargv() because
the av was NULL.  I don't know that returning Nullfp is
the best thing to do, but it dodges the segfault and
introduces no test failures.

p4raw-id: //depot/perl@19077

1 files changed, 2 insertions, 0 deletions

diff --git a/doio.c b/doio.c
index a1cc42abf0..15983919ca 100644
--- a/doio.c
+++ b/doio.c
@@ -717,6 +717,8 @@ Perl_nextargv(pTHX_ register GV *gv)
 #endif
     }
     PL_filemode = 0;
+    if (!GvAV(gv))
+        return Nullfp;
     while (av_len(GvAV(gv)) >= 0) {
 	STRLEN oldlen;
 	sv = av_shift(GvAV(gv));