make it an error to look for magic hv backref

Now that we only store a stash's backref AV in xhv_backreferences,
make it a panic if we don't find it there, rather than falling back to
look for backref magic.

1 files changed, 10 insertions, 8 deletions

diff --git a/sv.c b/sv.c
index c841dc90ec..4ca7333b82 100644
--- a/sv.c
+++ b/sv.c
@@ -5373,14 +5373,16 @@ Perl_sv_del_backref(pTHX_ SV *const tsv, SV *const sv)
 
     PERL_ARGS_ASSERT_SV_DEL_BACKREF;
 
-    if (SvTYPE(tsv) == SVt_PVHV && SvOOK(tsv)) {
-	av = *Perl_hv_backreferences_p(aTHX_ MUTABLE_HV(tsv));
-	/* We mustn't attempt to "fix up" the hash here by moving the
-	   backreference array back to the hv_aux structure, as that is stored
-	   in the main HvARRAY(), and hfreentries assumes that no-one
-	   reallocates HvARRAY() while it is running.  */
-    }
-    if (!av) {
+    if (SvTYPE(tsv) == SVt_PVHV) {
+	if (SvOOK(tsv)) {
+	    /* SvOOK: We must avoid creating the hv_aux structure if its
+	     * not already there, as that is stored in the main HvARRAY(),
+	     * and hfreentries assumes that no-one reallocates HvARRAY()
+	     * while it is running.  */
+	    av = *Perl_hv_backreferences_p(aTHX_ MUTABLE_HV(tsv));
+	}
+    }
+    else {
 	const MAGIC *const mg
 	    = SvMAGICAL(tsv) ? mg_find(tsv, PERL_MAGIC_backref) : NULL;
 	if (mg)