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.

foo renamed from bar:26d3ca0dfd18e44d796b564e38dd173c9668d3a9
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0       6      0       0 26d3ca0dfd18 000000000000 000000000000
     1         6       7      1       1 d267bddd54f7 26d3ca0dfd18 000000000000