tests/test-empty-dir.out

Always show short help when an unknown command is given.

+ hg init
+ hg add a
+ hg commit -m first -d 0 0 a
+ hg add sub/b
+ hg commit -m second -d 0 0 sub/b
321
+ hg co 0
cat: sub/b: No such file or directory
ls: sub: No such file or directory