array_change_key_case(): Throw ValueError on invalid argument (php#15883)

Author: Girgias

ext/standard/array.c

@@ -4799,21 +4799,26 @@ PHP_FUNCTION(array_change_key_case)
 	zend_string *string_key;
 	zend_string *new_key;
 	zend_ulong num_key;
-	zend_long change_to_upper=0;
+	zend_long change_to_upper = PHP_CASE_LOWER;
 
 	ZEND_PARSE_PARAMETERS_START(1, 2)
 		Z_PARAM_ARRAY(array)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_LONG(change_to_upper)
 	ZEND_PARSE_PARAMETERS_END();
 
+	if (change_to_upper != PHP_CASE_LOWER && change_to_upper != PHP_CASE_UPPER) {
+		zend_argument_value_error(2, "must be either CASE_LOWER or CASE_UPPER");
+		RETURN_THROWS();
+	}
+
 	array_init_size(return_value, zend_hash_num_elements(Z_ARRVAL_P(array)));
 
 	ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(array), num_key, string_key, entry) {
 		if (!string_key) {
 			entry = zend_hash_index_update(Z_ARRVAL_P(return_value), num_key, entry);
 		} else {
-			if (change_to_upper) {
+			if (change_to_upper == PHP_CASE_UPPER) {
 				new_key = zend_string_toupper(string_key);
 			} else {
 				new_key = zend_string_tolower(string_key);

ext/standard/tests/array/array_change_key_case_flag_error.phpt

@@ -0,0 +1,14 @@
+--TEST--
+array_change_key_case(): invalid $case argument
+--FILE--
+<?php
+
+try {
+    array_change_key_case([], -10);
+} catch (Throwable $e) {
+    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+}
+
+?>
+--EXPECT--
+ValueError: array_change_key_case(): Argument #2 ($case) must be either CASE_LOWER or CASE_UPPER