Fix support for upgrading encrypted wikis

Importing an encrypted wiki ordinarily doesn’t place the password in
the password vault on the basis that one ought to be able to import
from a file without automatically inheriting its password.

Now there’s a configuration option that can be used by the upgrade
plugin to cause the password vault to be updated with any password
entered by the user. The end result is that the user only needs to
enter their password once.

plugins/tiddlywiki/upgrade/UpgradeWizard.tid

@@ -37,11 +37,19 @@ The following tiddlers will be included in the upgrade <$button message="tw-perf
 
 Upgrade completed. Click the button below to save your upgraded ~TiddlyWiki file
 
+<$reveal type="match" state="$:/isEncrypted" text="yes">
+
+The file will be encrypted with your existing password
+
+</$reveal>
+
 {{$:/plugins/tiddlywiki/upgrade/save}}
 
----
+Make sure that you keep a safe copy of your previous ~TiddlyWiki file.
 
-{{$:/snippets/encryptionstatus}}
+Close this browser window to prevent others from being able to access your data.
+
+For help and support, visit [[the TiddlyWiki discussion forum|http://groups.google.com/group/TiddlyWiki]].
 
 </$reveal>
 

plugins/tiddlywiki/upgrade/config.js

@@ -0,0 +1,25 @@
+/*\
+title: $:/plugins/tiddlywiki/upgrade/config.js
+type: application/javascript
+module-type: startup
+
+Startup module for configuring the upgrade plugin
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+// Export name and synchronous status
+exports.name = "upgrade-config";
+exports.before = ["startup"];
+exports.synchronous = true;
+
+exports.startup = function() {
+	// See $tw.utils.decryptStoreAreaInteractive() in $:/core/modules/utils/crypto.js
+	$tw.config.usePasswordVault = true;
+};
+
+})();