Make sure array_splice() always returns an array

Return an array even if the return value isn't used. This allows us
to add the arginfo return type.

Author: nikic

ext/standard/array.c

@@ -3382,7 +3382,7 @@ PHP_FUNCTION(array_unshift)
 }
 /* }}} */
 
-/* {{{ proto array|null array_splice(array input, int offset [, int length [, array replacement]])
+/* {{{ proto array array_splice(array input, int offset [, int length [, array replacement]])
    Removes the elements designated by offset and length and replace them with supplied array */
 PHP_FUNCTION(array_splice)
 {
@@ -3434,6 +3434,9 @@ PHP_FUNCTION(array_splice)
 		/* Initialize return value */
 		array_init_size(return_value, size > 0 ? (uint32_t)size : 0);
 		rem_hash = Z_ARRVAL_P(return_value);
+	} else {
+		/* The return value will not be used, but make sure it still has the correct type. */
+		RETVAL_EMPTY_ARRAY();
 	}
 
 	/* Perform splice */

ext/standard/basic_functions.c

@@ -365,7 +365,7 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_array_unshift, 0, 1, IS_LONG, 0)
 	ZEND_ARG_VARIADIC_INFO(0, vars)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_array_splice, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_array_splice, 0, 2, IS_ARRAY, 0)
 	ZEND_ARG_INFO(1, arg) /* ARRAY_INFO(1, arg, 0) */
 	ZEND_ARG_INFO(0, offset)
 	ZEND_ARG_INFO(0, length)