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.
Test hangup signal in the middle of transaction
$ "$TESTDIR/hghave" serve fifo || exit 80
$ hg init
$ mkfifo p
$ hg serve --stdio < p 1>out 2>&1 &
$ P=$!
Do test while holding fifo open
$ (
> echo lock
> echo addchangegroup
> while [ ! -s .hg/store/journal ]; do sleep 0; done
> kill -HUP $P
> ) > p
$ wait
$ cat out
0
0
adding changesets
transaction abort!
rollback completed
killed!
$ echo .hg/* .hg/store/*
.hg/00changelog.i .hg/journal.bookmarks .hg/journal.branch .hg/journal.desc .hg/journal.dirstate .hg/requires .hg/store .hg/store/00changelog.i .hg/store/00changelog.i.a .hg/store/journal.phaseroots