All: Fixes #2091: Handle WebDAV servers that do not return a last modified date (fixes mail.ru)

ReactNativeClient/lib/WebDavApi.js

@@ -195,6 +195,8 @@ class WebDavApi {
 		}
 
 		if (outputType === 'string') {
+			if (!output) throw new JoplinError(`String property not found: ${propName}: ${JSON.stringify(resource)}`, 'stringNotFound');
+
 			// If the XML has not attribute the value is directly a string
 			// If the XML node has attributes, the value is under "_".
 			// Eg for this XML, the string will be under {"_":"Thu, 01 Feb 2018 17:24:05 GMT"}:

ReactNativeClient/lib/components/shared/config-shared.js

@@ -55,6 +55,8 @@ shared.checkSyncConfigMessages = function(comp) {
 };
 
 shared.checkNextcloudApp = async function(comp, settings) {
+	if (settings['sync.target'] !== 5) return;
+
 	comp.setState({ checkNextcloudAppResult: 'checking' });
 	let result = null;
 	const appApi = await reg.syncTargetNextcloud().appApi();

ReactNativeClient/lib/file-api-driver-webdav.js

@@ -58,7 +58,17 @@ class FileApiDriverWebDav {
 			}
 		}
 
-		const lastModifiedString = this.api().resourcePropByName(resource, 'string', 'd:getlastmodified');
+		let lastModifiedString = null;
+
+		try {
+			lastModifiedString = this.api().resourcePropByName(resource, 'string', 'd:getlastmodified');
+		} catch (error) {
+			if (error.code === 'stringNotFound') {
+				// OK - the logic to handle this is below
+			} else {
+				throw error;
+			}
+		}
 
 		// Note: Not all WebDAV servers return a getlastmodified date (eg. Seafile, which doesn't return the
 		// property for folders) so we can only throw an error if it's a file.