[master] DAV: Return data-fingerprint always when asked (#25482)

For owncloud/client#5056
Users can configure arbitrary subfolders for syncing, therefore we should
always return it when asked for.
The sync client makes sure to not always ask for it to save bandwidth.

apps/dav/lib/Connector/Sabre/FilesPlugin.php

@@ -324,18 +324,13 @@ class FilesPlugin extends ServerPlugin {
 				return $displayName;
 			});
 
-			$propFind->handle(self::DATA_FINGERPRINT_PROPERTYNAME, function() use ($node) {
-				if ($node->getPath() === '/') {
-					return $this->config->getSystemValue('data-fingerprint', '');
-				}
-			});
-
 			$propFind->handle(self::HAS_PREVIEW_PROPERTYNAME, function () use ($node) {
 				return json_encode($this->previewManager->isAvailable($node->getFileInfo()));
 			});
 		}
 
-		if ($node instanceof \OCA\DAV\Files\FilesHome) {
+		if ($node instanceof \OCA\DAV\Connector\Sabre\Node
+			|| $node instanceof \OCA\DAV\Files\FilesHome) {
 			$propFind->handle(self::DATA_FINGERPRINT_PROPERTYNAME, function() use ($node) {
 				return $this->config->getSystemValue('data-fingerprint', '');
 			});

apps/dav/tests/unit/Connector/Sabre/FilesPluginTest.php

@@ -213,7 +213,8 @@ class FilesPluginTest extends TestCase {
 		$this->assertEquals('http://example.com/', $propFind->get(self::DOWNLOADURL_PROPERTYNAME));
 		$this->assertEquals('foo', $propFind->get(self::OWNER_ID_PROPERTYNAME));
 		$this->assertEquals('M. Foo', $propFind->get(self::OWNER_DISPLAY_NAME_PROPERTYNAME));
-		$this->assertEquals([self::SIZE_PROPERTYNAME, self::DATA_FINGERPRINT_PROPERTYNAME], $propFind->get404Properties());
+		$this->assertEquals('my_fingerprint', $propFind->get(self::DATA_FINGERPRINT_PROPERTYNAME));
+		$this->assertEquals([self::SIZE_PROPERTYNAME], $propFind->get404Properties());
 	}
 
 	public function testGetPropertiesForFileHome() {
@@ -357,7 +358,8 @@ class FilesPluginTest extends TestCase {
 		$this->assertEquals(1025, $propFind->get(self::SIZE_PROPERTYNAME));
 		$this->assertEquals('DWCKMSR', $propFind->get(self::PERMISSIONS_PROPERTYNAME));
 		$this->assertEquals(null, $propFind->get(self::DOWNLOADURL_PROPERTYNAME));
-		$this->assertEquals([self::DOWNLOADURL_PROPERTYNAME, self::DATA_FINGERPRINT_PROPERTYNAME], $propFind->get404Properties());
+		$this->assertEquals('my_fingerprint', $propFind->get(self::DATA_FINGERPRINT_PROPERTYNAME));
+		$this->assertEquals([self::DOWNLOADURL_PROPERTYNAME], $propFind->get404Properties());
 	}
 
 	public function testGetPropertiesForRootDirectory() {