Merge pull request #4839 from mhsdesign/bugfix/4595-avoid-parse-parti…

…als-cache-to-crash-in-rare-case

BUGFIX: Fusion avoid error parser cache to crash if cache is broken

Neos.Fusion/Classes/Core/Cache/ParserCache.php

@@ -78,11 +78,16 @@ public function cacheForDsl(string $identifier, string $code, \Closure $generate
 
     private function cacheForIdentifier(string $identifier, \Closure $generateValueToCache): mixed
     {
-        if ($this->parsePartialsCache->has($identifier)) {
-            return $this->parsePartialsCache->get($identifier);
+        $value = $this->parsePartialsCache->get($identifier);
+        if ($value !== false) {
+            return $value;
         }
         $value = $generateValueToCache();
-        $this->parsePartialsCache->set($identifier, $value);
+        if ($value !== false) {
+            // in the rare edge-case of a fusion dsl returning `false` we cannot cache it,
+            // as the above get would be ignored. This is an acceptable compromise.
+            $this->parsePartialsCache->set($identifier, $value);
+        }
         return $value;
     }