posix: fix split() for the case where the path is at the root of the filesystem
posixpath.split() strips '/' from the dirname *unless it is the root*. This
patch reproduces this behavior in posix.split(). The old behavior causes a
crash when creating a file at the root of the repo with localrepo.wfile()
when the repo is at the root of the filesystem.
#!/bin/bash
hg init rebase
cd rebase
# @ 7: 'H'
# |
# | o 6: 'G'
# |/|
# o | 5: 'F'
# | |
# | o 4: 'E'
# |/
# | o 3: 'D'
# | |
# | o 2: 'C'
# | |
# | o 1: 'B'
# |/
# o 0: 'A'
echo A > A
hg ci -Am A
echo B > B
hg ci -Am B
echo C > C
hg ci -Am C
echo D > D
hg ci -Am D
hg up -q -C 0
echo E > E
hg ci -Am E
hg up -q -C 0
echo F > F
hg ci -Am F
hg merge -r 4
hg ci -m G
hg up -q -C 5
echo H > H
hg ci -Am H
hg bundle -a ../rebase.hg
cd ..
rm -Rf rebase