Merge pull request #907 from SISheogorath/fix/historyLZString

Some minor improvements for LZString handling

lib/history.js

@@ -31,6 +31,15 @@ function getHistory (userid, callback) {
       history = JSON.parse(user.history)
       // migrate LZString encoded note id to base64url encoded note id
       for (let i = 0, l = history.length; i < l; i++) {
+        // Calculate minimal string length for an UUID that is encoded
+        // base64 encoded and optimize comparsion by using -1
+        // this should make a lot of LZ-String parsing errors obsolete
+        // as we can assume that a nodeId that is 48 chars or longer is a
+        // noteID.
+        const base64UuidLength = ((4 * 36) / 3) - 1
+        if (!(history[i].id.length > base64UuidLength)) {
+          continue
+        }
         try {
           let id = LZString.decompressFromBase64(history[i].id)
           if (id && models.Note.checkNoteIdValid(id)) {
@@ -38,9 +47,13 @@ function getHistory (userid, callback) {
           }
         } catch (err) {
           // most error here comes from LZString, ignore
+          if (err.message === 'Cannot read property \'charAt\' of undefined') {
+            logger.warning('Looks like we can not decode "' + history[i].id + '" with LZString. Can be ignored.')
+          } else {
             logger.error(err)
           }
         }
+      }
       history = parseHistoryToObject(history)
     }
     if (config.debug) {

lib/models/note.js

@@ -227,7 +227,11 @@ module.exports = function (sequelize, DataTypes) {
               var id = LZString.decompressFromBase64(noteId)
               if (id && Note.checkNoteIdValid(id)) { return callback(null, id) } else { return _callback(null, null) }
             } catch (err) {
+              if (err.message === 'Cannot read property \'charAt\' of undefined') {
+                logger.warning('Looks like we can not decode "' + noteId + '" with LZString. Can be ignored.')
+              } else {
                 logger.error(err)
+              }
               return _callback(null, null)
             }
           },