Fix arg count check when a variadic placeholder exists

Author: arnaud-lb

Zend/tests/partial_application/errors_001.phpt

@@ -41,10 +41,18 @@ try {
 } catch (Error $ex) {
     printf("%s: %s\n", $ex::class, $ex->getMessage());
 }
+
+try {
+    foo(?, ?, ?, ?, ...);
+} catch (Error $ex) {
+    printf("%s: %s\n", $ex::class, $ex->getMessage());
+}
+
 ?>
 --EXPECT--
 ArgumentCountError: Partial application of foo() expects exactly 3 arguments, 1 given
 ArgumentCountError: Partial application of foo() expects at most 3 arguments, 4 given
 ArgumentCountError: Partial application of C::f() expects exactly 3 arguments, 1 given
 ArgumentCountError: Partial application of property_exists() expects exactly 2 arguments, 1 given
 ArgumentCountError: Partial application of usleep() expects at most 1 arguments, 2 given
+ArgumentCountError: Partial application of foo() expects at most 3 arguments, 4 given

Zend/zend_partial.c

@@ -94,20 +94,18 @@ static zend_result zp_args_check(const zend_function *function,
 		} ZEND_HASH_FOREACH_END();
 	}
 
-	// TODO: should be just 'argc', since the placeholder param doesn't increase argc?
-	uint32_t num = argc + (uses_variadic_placeholder ? -1 : 0);
-
-	if (num < function->common.required_num_args) {
+	if (argc < function->common.required_num_args) {
 		if (uses_variadic_placeholder) {
+			/* Missing args will be turned into placeholders */
 			return SUCCESS;
 		}
 
 		zend_partial_args_underflow(
-			function, num, function->common.required_num_args);
+			function, argc, function->common.required_num_args);
 		return FAILURE;
-	} else if (num > function->common.num_args &&
+	} else if (argc > function->common.num_args &&
 			!(function->common.fn_flags & ZEND_ACC_VARIADIC)) {
-		zend_partial_args_overflow(function, num, function->common.num_args);
+		zend_partial_args_overflow(function, argc, function->common.num_args);
 		return FAILURE;
 	}