[FOLLOWUP][BUGFIX] Respect interfaces as well when checking class existence

Add accidentally forgotten guard clause for case insensitivity.

Releases: master, 6.2
Resolves: #65434
Change-Id: I374a7201f3c5ef356883302fc0825f9a02ef0c30
Reviewed-on: http://review.typo3.org/37423


Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>

typo3/contrib/vendor/helhum/class-alias-loader/Classes/Composer/ClassAliasLoader.php

@@ -100,7 +100,10 @@ class ClassAliasLoader {
 	 */
 	public function loadClass($className) {
 		if (!$this->caseSensitiveClassLoading) {
-			$className = strtolower($className);
+			$lowerCasedClassName = strtolower($className);
+			if ($this->composerClassLoader->findFile($lowerCasedClassName)) {
+				return $this->composerClassLoader->loadClass($lowerCasedClassName);
+			}
 		}
 		return $this->composerClassLoader->loadClass($className);
 	}