Don't use UNREFs during array operations

Perform DEREFs instead. We were already doing this in some, but not
all places.

While UNREFs are supposed to be transparent, in practice they have
rare observable side effects. Calling array_merge() on an array
should never change how that array behaves.

Author: nikic

ext/standard/array.c

@@ -3612,7 +3612,7 @@ PHP_FUNCTION(array_slice)
 				}
 				if (UNEXPECTED(Z_ISREF_P(entry)) &&
 					UNEXPECTED(Z_REFCOUNT_P(entry) == 1)) {
-					ZVAL_UNREF(entry);
+					entry = Z_REFVAL_P(entry);
 				}
 				Z_TRY_ADDREF_P(entry);
 				ZEND_HASH_FILL_ADD(entry);
@@ -3725,7 +3725,7 @@ PHPAPI int php_array_merge(HashTable *dest, HashTable *src) /* {{{ */
 			ZEND_HASH_FOREACH_VAL(src, src_entry) {
 				if (UNEXPECTED(Z_ISREF_P(src_entry)) &&
 					UNEXPECTED(Z_REFCOUNT_P(src_entry) == 1)) {
-					ZVAL_UNREF(src_entry);
+					src_entry = Z_REFVAL_P(src_entry);
 				}
 				Z_TRY_ADDREF_P(src_entry);
 				ZEND_HASH_FILL_ADD(src_entry);
@@ -3735,7 +3735,7 @@ PHPAPI int php_array_merge(HashTable *dest, HashTable *src) /* {{{ */
 		ZEND_HASH_FOREACH_STR_KEY_VAL(src, string_key, src_entry) {
 			if (UNEXPECTED(Z_ISREF_P(src_entry) &&
 				Z_REFCOUNT_P(src_entry) == 1)) {
-				ZVAL_UNREF(src_entry);
+				src_entry = Z_REFVAL_P(src_entry);
 			}
 			Z_TRY_ADDREF_P(src_entry);
 			if (string_key) {
@@ -3883,7 +3883,7 @@ static inline void php_array_merge_or_replace_wrapper(INTERNAL_FUNCTION_PARAMETE
 				ZEND_HASH_FOREACH_VAL(src, src_entry) {
 					if (UNEXPECTED(Z_ISREF_P(src_entry) &&
 						Z_REFCOUNT_P(src_entry) == 1)) {
-						ZVAL_UNREF(src_entry);
+						src_entry = Z_REFVAL_P(src_entry);
 					}
 					Z_TRY_ADDREF_P(src_entry);
 					ZEND_HASH_FILL_ADD(src_entry);
@@ -3895,7 +3895,7 @@ static inline void php_array_merge_or_replace_wrapper(INTERNAL_FUNCTION_PARAMETE
 			ZEND_HASH_FOREACH_STR_KEY_VAL(src, string_key, src_entry) {
 				if (UNEXPECTED(Z_ISREF_P(src_entry) &&
 					Z_REFCOUNT_P(src_entry) == 1)) {
-					ZVAL_UNREF(src_entry);
+					src_entry = Z_REFVAL_P(src_entry);
 				}
 				Z_TRY_ADDREF_P(src_entry);
 				if (EXPECTED(string_key)) {
@@ -4285,7 +4285,7 @@ PHP_FUNCTION(array_reverse)
 			ZEND_HASH_REVERSE_FOREACH_VAL(Z_ARRVAL_P(input), entry) {
 				if (UNEXPECTED(Z_ISREF_P(entry) &&
 					Z_REFCOUNT_P(entry) == 1)) {
-					ZVAL_UNREF(entry);
+					entry = Z_REFVAL_P(entry);
 				}
 				Z_TRY_ADDREF_P(entry);
 				ZEND_HASH_FILL_ADD(entry);
@@ -4679,7 +4679,7 @@ static void php_array_intersect_key(INTERNAL_FUNCTION_PARAMETERS, int data_compa
 			if (Z_TYPE_P(val) == IS_UNDEF) continue;
 		}
 		if (Z_ISREF_P(val) && Z_REFCOUNT_P(val) == 1) {
-			ZVAL_UNREF(val);
+			val = Z_REFVAL_P(val);
 		}
 		if (p->key == NULL) {
 			ok = 1;
@@ -5090,7 +5090,7 @@ static void php_array_diff_key(INTERNAL_FUNCTION_PARAMETERS, int data_compare_ty
 			if (Z_TYPE_P(val) == IS_UNDEF) continue;
 		}
 		if (Z_ISREF_P(val) && Z_REFCOUNT_P(val) == 1) {
-			ZVAL_UNREF(val);
+			val = Z_REFVAL_P(val);
 		}
 		if (p->key == NULL) {
 			ok = 1;