add CVf_CVGV_RC flag

after the recent commit 803f274831f937654d48f8cf0468521cbf8f5dff,
the CvGV field is sometimes reference counted. Since it was intended that
the reference counting would happen only for anonymous CVs, the CVf_ANON
flag was co-opted to indicate whether RC was being used. This is not
entirely robust; for example, sub __ANON__ {} is a non-anon sub which
points to the same GV used by anon subs, which while itself doesn't
directly break things, shows that the potential for breakage is there.

So add a separate flag just to indicate the reference count status of the
CvGV field.

1 files changed, 4 insertions, 4 deletions

diff --git a/gv.c b/gv.c
index 47648639cc..9eaf76c240 100644
--- a/gv.c
+++ b/gv.c
@@ -206,10 +206,11 @@ Perl_cvgv_set(pTHX_ CV* cv, GV* gv)
 	return;
 
     if (oldgv) {
-	if (CvANON(cv))
+	if (CvCVGV_RC(cv)) {
 	    SvREFCNT_dec(oldgv);
+	    CvCVGV_RC_off(cv);
+	}
 	else {
-	    assert(strNE(GvNAME(oldgv),"__ANON__"));
 	    sv_del_backref(MUTABLE_SV(oldgv), MUTABLE_SV(cv));
 	}
     }
@@ -220,11 +221,10 @@ Perl_cvgv_set(pTHX_ CV* cv, GV* gv)
 	return;
 
     if (CvANON(cv)) {
-	assert(strnEQ(GvNAME(gv),"__ANON__", 8));
+	CvCVGV_RC_on(cv);
 	SvREFCNT_inc_simple_void_NN(gv);
     }
     else {
-	assert(strNE(GvNAME(gv),"__ANON__"));
 	Perl_sv_add_backref(aTHX_ MUTABLE_SV(gv), MUTABLE_SV(cv));
     }
 }