purge: abort with missing files avoiding problems with name-mangling fs In a name mangling filesystem (e.g. a case insensitive one) dirstate.walk() can yield filenames different from the ones stored in the dirstate. This already confuses the status and add commands, but with purge this may cause data loss. To prevent this purge refuses to work if there are missing files and has a 'force' option if the user knows it is safe. Even with the force option purge checks if any of the missing files is still available in the working dir: if so there may be some problem with the underlying filesystem, so it unconditionally aborts.