Restore array_key_exists() compatibility for ArrayObject

Doing this by special-casing array_key_exists() for ArrayObject.

Author: nikic

UPGRADING

@@ -40,7 +40,6 @@ PHP 7.4 UPGRADE NOTES
     flag was specified. Other affected operations are:
 
      * ReflectionObject::getProperties()
-     * array_key_exists(). Use isset() or offsetExists() instead.
      * reset(), current(), etc. Use Iterator methods instead.
      * Potentially others working on object properties as a list.
 

Zend/zend_object_handlers.c

@@ -1754,6 +1754,7 @@ ZEND_API HashTable *zend_std_get_properties_for(zval *obj, zend_prop_purpose pur
 		case ZEND_PROP_PURPOSE_SERIALIZE:
 		case ZEND_PROP_PURPOSE_VAR_EXPORT:
 		case ZEND_PROP_PURPOSE_JSON:
+		case _ZEND_PROP_PURPOSE_ARRAY_KEY_EXISTS:
 			ht = Z_OBJ_HT_P(obj)->get_properties(obj);
 			if (ht && !(GC_FLAGS(ht) & GC_IMMUTABLE)) {
 				GC_ADDREF(ht);

Zend/zend_object_handlers.h

@@ -106,6 +106,8 @@ typedef enum _zend_prop_purpose {
 	ZEND_PROP_PURPOSE_VAR_EXPORT,
 	/* Used for json_encode(). */
 	ZEND_PROP_PURPOSE_JSON,
+	/* array_key_exists(). Not intended for general use! */
+	_ZEND_PROP_PURPOSE_ARRAY_KEY_EXISTS,
 	/* Dummy member to ensure that "default" is specified. */
 	_ZEND_PROP_PURPOSE_NON_EXHAUSTIVE_ENUM
 } zend_prop_purpose;

ext/spl/spl_array.c

@@ -805,6 +805,7 @@ static HashTable *spl_array_get_properties_for(zval *object, zend_prop_purpose p
 			break;
 		case ZEND_PROP_PURPOSE_VAR_EXPORT:
 		case ZEND_PROP_PURPOSE_JSON:
+		case _ZEND_PROP_PURPOSE_ARRAY_KEY_EXISTS:
 			dup = 0;
 			break;
 		default:

ext/spl/tests/bug61347.phpt

@@ -12,7 +12,7 @@ var_dump(isset($b['no_exists'])); //false
 var_dump(empty($b['b'])); //true
 var_dump(empty($b[37])); //true
 
-var_dump(array_key_exists('b', $b)); //false
+var_dump(array_key_exists('b', $b)); //true
 var_dump($b['b']);
 
 $a = array('b' => '', 37 => false);
@@ -31,7 +31,7 @@ bool(false)
 bool(false)
 bool(true)
 bool(true)
-bool(false)
+bool(true)
 NULL
 bool(true)
 bool(true)

ext/standard/array.c

@@ -6247,34 +6247,38 @@ PHP_FUNCTION(array_map)
    Checks if the given key or index exists in the array */
 PHP_FUNCTION(array_key_exists)
 {
-	zval *key;					/* key to check for */
-	HashTable *array;			/* array to check in */
+	zval *key;
+	zval *array;
+	HashTable *ht;
 
 	ZEND_PARSE_PARAMETERS_START(2, 2)
 		Z_PARAM_ZVAL(key)
-		Z_PARAM_ARRAY_OR_OBJECT_HT(array)
+		Z_PARAM_ARRAY_OR_OBJECT(array)
 	ZEND_PARSE_PARAMETERS_END();
 
+	if (EXPECTED(Z_TYPE_P(array) == IS_ARRAY)) {
+		ht = Z_ARRVAL_P(array);
+	} else {
+		ht = zend_get_properties_for(array, ZEND_PROP_PURPOSE_ARRAY_CAST);
+	}
+
 	switch (Z_TYPE_P(key)) {
 		case IS_STRING:
-			if (zend_symtable_exists_ind(array, Z_STR_P(key))) {
-				RETURN_TRUE;
-			}
-			RETURN_FALSE;
+			RETVAL_BOOL(zend_symtable_exists_ind(ht, Z_STR_P(key)));
+			break;
 		case IS_LONG:
-			if (zend_hash_index_exists(array, Z_LVAL_P(key))) {
-				RETURN_TRUE;
-			}
-			RETURN_FALSE;
+			RETVAL_BOOL(zend_hash_index_exists(ht, Z_LVAL_P(key)));
+			break;
 		case IS_NULL:
-			if (zend_hash_exists_ind(array, ZSTR_EMPTY_ALLOC())) {
-				RETURN_TRUE;
-			}
-			RETURN_FALSE;
-
+			RETVAL_BOOL(zend_hash_exists_ind(ht, ZSTR_EMPTY_ALLOC()));
+			break;
 		default:
 			php_error_docref(NULL, E_WARNING, "The first argument should be either a string or an integer");
-			RETURN_FALSE;
+			RETVAL_FALSE;
+	}
+
+	if (Z_TYPE_P(array) != IS_ARRAY) {
+		zend_release_properties(ht);
 	}
 }
 /* }}} */