Casestop Extension
This extension is not distributed with Mercurial.
Author: Friedrich Kastner-Masilko
Download site: http://bitbucket.org/face/timestamp/ (Developed with Mercurial 1.1.2 - works with 1.2)
This extension is still in alpha, use it at your own risk.
Overview
This extension stops you from commiting a CaseFolding collision. In the current version of Mercurial, it is possible to introduce case-folding collisions by means of Merge and RebaseExtension while using a repository solely on case-folding file-systems like NTFS. In addition, such a collision can not be detected by the user until he tries to update back to this commit.
Furthermore, on projects using repos shared by users of Windows and POSIX-systems, it is easy for a POSIX user to cause the Windows folks a hard time. With this extension, you'll be stopped before commiting the crime...
Configuration
Configure your .hgrc to enable the precommit hook:
[hooks] precommit.casestop = python:hgext.casestop.hook