Don't crash if the symbol table entry for ISA isn't a typeglob.

p4raw-id: //depot/perl@30442

2 files changed, 8 insertions, 2 deletions

diff --git a/gv.c b/gv.c
index e03521e947..aac25b6cce 100644
--- a/gv.c
+++ b/gv.c
@@ -368,7 +368,7 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
     }
 
     gvp = (GV**)hv_fetchs(stash, "ISA", FALSE);
-    av = (gvp && (gv = *gvp) && gv != (GV*)&PL_sv_undef) ? GvAV(gv) : NULL;
+    av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
 
     /* create and re-create @.*::SUPER::ISA on demand */
     if (!av || !SvMAGIC(av)) {
diff --git a/t/op/gv.t b/t/op/gv.t
index d243fb70a3..4475912f53 100755
--- a/t/op/gv.t
+++ b/t/op/gv.t
@@ -12,7 +12,7 @@ BEGIN {
 use warnings;
 
 require './test.pl';
-plan( tests => 154 );
+plan( tests => 155 );
 
 # type coersion on assignment
 $foo = 'foo';
@@ -453,6 +453,12 @@ foreach my $value ([1,2,3], {1=>2}, *STDOUT{IO}, \&ok, *STDOUT{FORMAT}) {
 	"PERL_DONT_CREATE_GVSV shouldn't affect thingy syntax under strict");
 }
 
+{
+    # Bug reported by broquaint on IRC
+    *slosh::{HASH}->{ISA}=[];
+    slosh->import;
+    pass("gv_fetchmeth coped with the unexpected");
+}
 __END__
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