tests/test-issue1438.t

run-tests: fix whitelist/blacklist with directories on Windows

The file name is resolved with `os.path.relpath()` in the `Test` constructor,
which yields `\` on Windows.  That doesn't match the `/` separator when using
MSYS tools to build the list, and it isn't obvious that this is the problem
because directory separators can mostly be used interchangeably.  The
`--test-list` argument already seems to be properly handled.

#require symlink

https://bz.mercurial-scm.org/1438

  $ hg init

  $ ln -s foo link
  $ hg add link
  $ hg ci -mbad link
  $ hg rm link
  $ hg ci -mok
  $ hg diff -g -r 0:1 > bad.patch

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg import --no-commit bad.patch
  applying bad.patch

  $ hg status
  R link
  ? bad.patch