1. Open a .cpp file.
2. Place a breakpoint in the file.
3. Select the code line the breakpoint is at.
4. Press "Delete" key.
   The code line and the breakpoint disappear as expected.
5. Select "Undo" from the menu or press Ctrl+Z.
   The line is being restored but the breakpoint is gone.

Properly undoing would mean to restore the breakpoint, too.