curScore.version not updated after File > Save

Steps to reproduce bug
1. Open a score created in an old version of MuseScore (or import a MusicXML or MIDI file)
2. File > Save
3. Run a plugin that displays curScore.version
(such as Plugins > Version Numbers, http://musescore.org/en/project/versionnumbers

Expected behavior: curScore.version should update to indicate that it was saved using the current version of MuseScore

Actual behavior: curScore.version is not updated until you close and reopen the score.

MuseScore version: 1.2 stable and r.5478 nightly

(Operating System: Windows 7)