Crash after time signature delete

Steps to reproduce bug
1. Create new score in 4/4
2. Drag-and-drop a different time signature into measure 2 (such as 2/4)
3. Click to select the new time signature in measure 2
4. Press Del to remove the time signature
5. Click on an empty part of measure 2 to select (Notice that selection unexpectedly extends to the end of the piece)
6. Click "N" to begin note entry mode

Expected behavior: After step 4 measure 2 should revert to the time of the measures in front of it.

Actual behavior: Measures become corrupted and MuseScore crashes after step 6.

MuseScore version: r.2592 nightly

(Operating System: Windows XP)