[ErrorHandler] ignore @return when there is an @template

Author: nicolas-grekas

DebugClassLoader.php

@@ -371,9 +371,12 @@ public function checkAnnotations(\ReflectionClass $refl, string $class): array
 
         $parent = get_parent_class($class) ?: null;
         self::$returnTypes[$class] = [];
+        $classIsTemplate = false;
 
         // Detect annotations on the class
         if ($doc = $this->parsePhpDoc($refl)) {
+            $classIsTemplate = isset($doc['template']);
+
             foreach (['final', 'deprecated', 'internal'] as $annotation) {
                 if (null !== $description = $doc[$annotation][0] ?? null) {
                     self::${$annotation}[$class] = '' !== $description ? ' '.$description.(preg_match('/[.!]$/', $description) ? '' : '.') : '.';
@@ -517,6 +520,10 @@ public function checkAnnotations(\ReflectionClass $refl, string $class): array
             // To read method annotations
             $doc = $this->parsePhpDoc($method);
 
+            if (($classIsTemplate || isset($doc['template'])) && $method->hasReturnType()) {
+                unset($doc['return']);
+            }
+
             if (isset(self::$annotatedParameters[$class][$method->name])) {
                 $definedParameters = [];
                 foreach ($method->getParameters() as $parameter) {