Use ADDREF instead of DUP, it must be enough.

diff --git a/Zend/zend_variables.c b/Zend/zend_variables.c
index 3e68a38487af311683e921cb29aa44b8e92f70ae..41cba30109fd9c5e67a3d098f189f45a88585ae9 100644 (file)
--- a/Zend/zend_variables.c
+++ b/Zend/zend_variables.c
@@ -221,7 +221,7 @@ ZEND_API void zval_add_ref_unref(zval *p)
 {
        if (Z_REFCOUNTED_P(p)) {
                if (Z_ISREF_P(p)) {
-                       ZVAL_DUP(p, Z_REFVAL_P(p));
+                       ZVAL_COPY(p, Z_REFVAL_P(p));
                } else {
                        Z_ADDREF_P(p);
                }