symfony
diff --git a/‎src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php
Lines changed: 4 additions & 4 deletions b/‎src/Symfony/Component/Serializer/NameConverter/MetadataAwareNameConverter.php
Lines changed: 4 additions & 4 deletions
@@ -47,7 +47,7 @@ public function normalize($propertyName, string $class = null, string $format =
             return $this->normalizeFallback($propertyName, $class, $format, $context);
         }
 
-        if (!isset(self::$normalizeCache[$class][$propertyName])) {
+        if (!\array_key_exists($class, self::$normalizeCache) || !\array_key_exists($propertyName, self::$normalizeCache[$class])) {
             self::$normalizeCache[$class][$propertyName] = $this->getCacheValueForNormalization($propertyName, $class);
         }
 
@@ -64,7 +64,7 @@ public function denormalize($propertyName, string $class = null, string $format
         }
 
         $cacheKey = $this->getCacheKey($class, $context);
-        if (!isset(self::$denormalizeCache[$cacheKey][$propertyName])) {
+        if (!\array_key_exists($cacheKey, self::$denormalizeCache) || !\array_key_exists($propertyName, self::$denormalizeCache[$cacheKey])) {
             self::$denormalizeCache[$cacheKey][$propertyName] = $this->getCacheValueForDenormalization($propertyName, $class, $context);
         }
 
@@ -78,7 +78,7 @@ private function getCacheValueForNormalization(string $propertyName, string $cla
         }
 
         $attributesMetadata = $this->metadataFactory->getMetadataFor($class)->getAttributesMetadata();
-        if (!isset($attributesMetadata[$propertyName])) {
+        if (!\array_key_exists($propertyName, $attributesMetadata)) {
             return null;
         }
 
@@ -93,7 +93,7 @@ private function normalizeFallback(string $propertyName, string $class = null, s
     private function getCacheValueForDenormalization(string $propertyName, string $class, array $context): ?string
     {
         $cacheKey = $this->getCacheKey($class, $context);
-        if (!isset(self::$attributesMetadataCache[$cacheKey])) {
+        if (!\array_key_exists($cacheKey, self::$attributesMetadataCache)) {
             self::$attributesMetadataCache[$cacheKey] = $this->getCacheValueForAttributesMetadata($class, $context);
         }
Original file line number	Diff line number	Diff line change
`@@ -47,7 +47,7 @@ public function normalize($propertyName, string $class = null, string $format =`
`47`	`47`	`return $this->normalizeFallback($propertyName, $class, $format, $context);`
`48`	`48`	`}`
`49`	`49`
`50`		`- if (!isset(self::$normalizeCache[$class][$propertyName])) {`
	`50`	`+ if (!\array_key_exists($class, self::$normalizeCache) \|\| !\array_key_exists($propertyName, self::$normalizeCache[$class])) {`
`51`	`51`	`self::$normalizeCache[$class][$propertyName] = $this->getCacheValueForNormalization($propertyName, $class);`
`52`	`52`	`}`
`53`	`53`
`@@ -64,7 +64,7 @@ public function denormalize($propertyName, string $class = null, string $format`
`64`	`64`	`}`
`65`	`65`
`66`	`66`	`$cacheKey = $this->getCacheKey($class, $context);`
`67`		`- if (!isset(self::$denormalizeCache[$cacheKey][$propertyName])) {`
	`67`	`+ if (!\array_key_exists($cacheKey, self::$denormalizeCache) \|\| !\array_key_exists($propertyName, self::$denormalizeCache[$cacheKey])) {`
`68`	`68`	`self::$denormalizeCache[$cacheKey][$propertyName] = $this->getCacheValueForDenormalization($propertyName, $class, $context);`
`69`	`69`	`}`
`70`	`70`
`@@ -78,7 +78,7 @@ private function getCacheValueForNormalization(string $propertyName, string $cla`
`78`	`78`	`}`
`79`	`79`
`80`	`80`	`$attributesMetadata = $this->metadataFactory->getMetadataFor($class)->getAttributesMetadata();`
`81`		`- if (!isset($attributesMetadata[$propertyName])) {`
	`81`	`+ if (!\array_key_exists($propertyName, $attributesMetadata)) {`
`82`	`82`	`return null;`
`83`	`83`	`}`
`84`	`84`
`@@ -93,7 +93,7 @@ private function normalizeFallback(string $propertyName, string $class = null, s`
`93`	`93`	`private function getCacheValueForDenormalization(string $propertyName, string $class, array $context): ?string`
`94`	`94`	`{`
`95`	`95`	`$cacheKey = $this->getCacheKey($class, $context);`
`96`		`- if (!isset(self::$attributesMetadataCache[$cacheKey])) {`
	`96`	`+ if (!\array_key_exists($cacheKey, self::$attributesMetadataCache)) {`
`97`	`97`	`self::$attributesMetadataCache[$cacheKey] = $this->getCacheValueForAttributesMetadata($class, $context);`
`98`	`98`	`}`
`99`	`99`