Fix the Python path on Windows

On Windows, we want to run with a native Python, i.e. the separator is a
semicolon, and the paths should be Windows paths (although they're
allowed to have forward slashes instead of backslashes).

Since we're most likely running this in an MSYS2 Bash, allow for
`$TEST_DIRECTORY` to pretend to be a Unix path, and translate it via
`cygpath` into a Windows path.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

t/t9391-filter-repo-lib-usage.sh

@@ -4,7 +4,14 @@ test_description='Usage of git-filter-repo as a library'
 . ./test-lib.sh
 
 # for git_filter_repo.py import
-export PYTHONPATH=$(dirname $TEST_DIRECTORY):$PYTHONPATH
+case "$(uname -s)" in
+MINGW*|MSYS)
+	export PYTHONPATH=$(cygpath -am $TEST_DIRECTORY/..)\;$PYTHONPATH
+	;;
+*)
+	export PYTHONPATH=$(dirname $TEST_DIRECTORY):$PYTHONPATH
+	;;
+esac
 # Avoid writing git_filter_repo.pyc file
 export PYTHONDONTWRITEBYTECODE=1
 export CONTRIB_DIR=$TEST_DIRECTORY/../contrib/filter-repo-demos