checknlink: return False if .hgtmp file preexists (issue2517)
If os_link fails on Windows, errno is always errno.EINVAL,
so we can't really say if the testlink could not be created
because (a) the FS doesn't support hardlinks or (b) there
is a leaked .hgtmp file lying around from a previous crashed
run.
So let's err on the safe side, keep the code simple and assume
we can't detect hardlinks in both cases.
$ hg init a
$ echo a > a/a
$ hg --cwd a ci -Ama
adding a
$ hg clone a c
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b >> b/a
$ hg --cwd b ci -mb
Push should push to 'default' when 'default-push' not set:
$ hg --cwd b push
pushing to $TESTTMP/a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
Push should push to 'default-push' when set:
$ echo 'default-push = ../c' >> b/.hg/hgrc
$ hg --cwd b push
pushing to $TESTTMP/c
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files