change when to make CvGV refcounted

Rather than making CvGV refcounted if the CV is anon, decide based on
whether the GV pointed to by CvGV holds a reference back to us. Normally
these two will be equivalent, but this way is more robust if people are
doing weird things.

Also spotted an error with cv_clone not clearing the CVf_CVGV_RC flag on
the newly cloned cv. This shouldn't normally matter as it will get set
shortly anyway, but best to keep things logically correct.

1 files changed, 4 insertions, 4 deletions

diff --git a/gv.c b/gv.c
index 9eaf76c240..917cfb7ee9 100644
--- a/gv.c
+++ b/gv.c
@@ -216,17 +216,17 @@ Perl_cvgv_set(pTHX_ CV* cv, GV* gv)
     }
 
     CvGV(cv) = gv;
+    assert(!CvCVGV_RC(cv));
 
     if (!gv)
 	return;
 
-    if (CvANON(cv)) {
+    if (isGV_with_GP(gv) && GvGP(gv) && (GvCV(gv) == cv || GvFORM(gv) == cv))
+	Perl_sv_add_backref(aTHX_ MUTABLE_SV(gv), MUTABLE_SV(cv));
+    else {
 	CvCVGV_RC_on(cv);
 	SvREFCNT_inc_simple_void_NN(gv);
     }
-    else {
-	Perl_sv_add_backref(aTHX_ MUTABLE_SV(gv), MUTABLE_SV(cv));
-    }
 }