Soft fail in custom properties backend

This makes it possible for clients to still receive a file list (minus
the broken files) instead of getting no list at all

lib/private/connector/sabre/custompropertiesbackend.php

@@ -29,6 +29,7 @@ use Sabre\DAV\PropertyStorage\Backend\BackendInterface;
 use Sabre\DAV\PropFind;
 use Sabre\DAV\PropPatch;
 use Sabre\DAV\Tree;
+use Sabre\DAV\Exception\NotFound;
 
 class CustomPropertiesBackend implements BackendInterface {
 
@@ -94,8 +95,19 @@ class CustomPropertiesBackend implements BackendInterface {
      * @return void
      */
 	public function propFind($path, PropFind $propFind) {
-		$node = $this->tree->getNodeForPath($path);
-		if (!($node instanceof Node)) {
+		try {
+			$node = $this->tree->getNodeForPath($path);
+			if (!($node instanceof Node)) {
+				return;
+			}
+		} catch (NotFound $e) {
+			// in some rare (buggy) cases the node might not be found,
+			// we catch the exception to prevent breaking the whole list with a 404
+			// (soft fail)
+			\OC::$server->getLogger()->warning(
+				'Could not get node for path: \"' . $path . '\" : ' . $e->getMessage(),
+				array('app' => 'files')
+			);
 			return;
 		}
 

tests/lib/connector/sabre/custompropertiesbackend.php

@@ -101,6 +101,34 @@ class CustomPropertiesBackend extends \Test\TestCase {
 		$this->assertEquals(200, $result['customprop2']);
 	}
 
+	/**
+	 * Test that propFind on a missing file soft fails
+	 */
+	public function testPropFindMissingFileSoftFail() {
+		$this->tree->expects($this->any())
+			->method('getNodeForPath')
+			->with('/dummypath')
+			->will($this->throwException(new \Sabre\DAV\Exception\NotFound()));
+
+		$propFind = new \Sabre\DAV\PropFind(
+			'/dummypath',
+			array(
+				'customprop',
+				'customprop2',
+				'unsetprop',
+			),
+			0
+		);
+
+		$this->plugin->propFind(
+			'/dummypath',
+			$propFind
+		);
+
+		// no exception, soft fail
+		$this->assertTrue(true);
+	}
+
 	/**
 	 * Test setting/getting properties
 	 */