moving bracket causes crash

Steps to reproduce crash:
1. Make a horizontal bracket and then moving it left using ctrl+shift+left arrow
2. Append over a hundred measures.
3. Attempt to move horizontal brace to the right using ctrl+shift+right arrow causes crash.

In the attached Musescore file, steps 1+2 have been completed. Attempting step three causes crash.
This crash doesn't occur with a smaller file - remove the blank measures in the file and the crash will not reproduce.

Using nightly build 1778f37 under Windows 7.