fix(files): Do not array access null value

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

Author: susnux

lib/private/Files/Storage/Wrapper/Encoding.php

@@ -510,7 +510,9 @@ public function moveFromStorage(IStorage $sourceStorage, $sourceInternalPath, $t
 
 	public function getMetaData($path) {
 		$entry = $this->storage->getMetaData($this->findPathToUse($path));
-		$entry['name'] = trim(Filesystem::normalizePath($entry['name']), '/');
+		if ($entry !== null) {
+			$entry['name'] = trim(Filesystem::normalizePath($entry['name']), '/');
+		}
 		return $entry;
 	}
 

tests/lib/Files/Storage/Wrapper/EncodingTest.php

@@ -240,4 +240,12 @@ public function testNormalizedGetMetaData() {
 		$entry = $this->instance->getMetaData('/test/' . self::NFD_NAME);
 		$this->assertEquals(self::NFC_NAME, $entry['name']);
 	}
+
+	/**
+	 * Regression test of https://github.com/nextcloud/server/issues/50431
+	 */
+	public function testNoMetadata() {
+		$this->assertNull($this->instance->getMetaData('/test/null'));
+	}
+
 }