Fixes #11125: Fixed `JSON_ERROR_SYNTAX` for `json_decode(null)` in PHP 7

framework/CHANGELOG.md

@@ -14,6 +14,7 @@ Yii Framework 2 Change Log
 - Bug #10974: `yii.js` - fixed error in ajaxPrefilter event handler, caused by blocked frame (maximal)
 - Bug #11038: Fixed handling of intervals of 0 seconds in `yii\i18n\Formatter::asDuration()` (VirtualRJ)
 - Bug #11093: Fixed `yii\db\QueryBuilder::buildAndCondition()` to add query params passed directly by `yii\db\Expression` (CedricYii, silverfire)
+- Bug #11125: Fixed `JSON_ERROR_SYNTAX` for `json_decode(null)` in PHP 7 (fps01)
 - Bug: SQlite querybuilder did not create primary key with bigint for `TYPE_BIGPK` (cebe)
 - Enh #5469: Add mimetype validation by mask in FileValidator (kirsenn, samdark, silverfire)
 - Enh #8602: `yii\validators\DateValidator` skip validation for `timestampAttribute`, if it is already in correct format (klimov-paul)

framework/helpers/BaseJson.php

@@ -90,6 +90,8 @@ class BaseJson
     {
         if (is_array($json)) {
             throw new InvalidParamException('Invalid JSON data.');
+        } elseif ($json === null || $json === '') {
+            return null;
         }
         $decode = json_decode((string) $json, $asArray);
         static::handleJsonError(json_last_error());