Small fixes and improvements

www/common/common-thumbnail.js

@@ -25,6 +25,7 @@ define([
     ];
 
     Thumb.isSupportedType = function (file) {
+        if (!file) { return false; }
         var type = file.type;
         if (Util.isPlainTextFile(file.type, file.name)) {
             type = "text/plain";

www/common/cryptpad-common.js

@@ -9,12 +9,11 @@ define([
     '/common/outer/local-store.js',
     '/common/outer/worker-channel.js',
     '/common/outer/login-block.js',
-    '/file/file-crypto.js',
 
     '/customize/application_config.js',
     '/bower_components/nthen/index.js',
 ], function (Config, Messages, Util, Hash,
-            Messaging, Constants, Feedback, LocalStore, Channel, Block, FileCrypto,
+            Messaging, Constants, Feedback, LocalStore, Channel, Block,
             AppConfig, Nthen) {
 
 /*  This file exposes functionality which is specific to Cryptpad, but not to
@@ -588,9 +587,11 @@ define([
                 u8 = _u8;
             }));
         }).nThen(function (waitFor) {
-            FileCrypto.decrypt(u8, key, waitFor(function (err, _res) {
-                if (err || !_res.content) { return void waitFor.abort(); }
-                res = _res;
+            require(["/file/file-crypto.js"], waitFor(function (FileCrypto) {
+                FileCrypto.decrypt(u8, key, waitFor(function (err, _res) {
+                    if (err || !_res.content) { return void waitFor.abort(); }
+                    res = _res;
+                }));
             }));
         }).nThen(function (waitFor) {
             var ext = Util.parseFilename(data.title).ext;

www/common/sframe-common-outer.js

@@ -814,7 +814,7 @@ define([
             });
 
             sframeChan.on('Q_GET_FILE_THUMBNAIL', function (data, cb) {
-                if (!Cryptpad.fromFileData.href) {
+                if (!Cryptpad.fromFileData || !Cryptpad.fromFileData.href) {
                     return void cb({
                         error: "EINVAL",
                     });