System Information
Win7 x64

Blender Version
Broken: Blender 2.69 r60995
Worked: Blender 2.66.1 r55078

Creating a template_list in COMPACT mode lets users determine the index of the list item they want to see. But the index value is unrestricted, allowing invalid values to be entered which crash Blender (e.g. negative numbers).

Blender 2.66 "works" because it doesn't crash when the user enters an invalid index, not because it correctly restricts the value.

Exact steps for others to reproduce the error

1. Open blend file
   template_list_crash.blend81 KBDownload
2. Run script
3. Enter invalid number into the new UI element