Re: [PATCH v2/GSoC 4/4] t0301: test credential-cache support of XDG_RUNTIME_DIR

t0301 now tests git-credential-cache support for XDG user-specific
runtime file $XDG_RUNTIME_DIR/git/credential.sock. Specifically:

* if $XDG_RUNTIME_DIR exists, use socket at
  `$XDG_RUNTIME_DIR/git/credential-cache.sock`.

* otherwise, `/tmp/git-$uid/credential-cache.sock` is taken.

Signed-off-by: Hui Yiqun <redacted>
---
 t/t0301-credential-cache.sh | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/t/t0301-credential-cache.sh b/t/t0301-credential-cache.sh
index 82c8411..892d1ba 100755
--- a/t/t0301-credential-cache.sh
+++ b/t/t0301-credential-cache.sh

@@ -12,7 +12,34 @@ test -z "$NO_UNIX_SOCKETS" || {
 # don't leave a stale daemon running
 trap 'code=$?; git credential-cache exit; (exit $code); die' EXIT
 
+test_expect_success 'set $XDG_RUNTIME_DIR' '
+	XDG_RUNTIME_DIR=$HOME/xdg_runtime/
+'
+
+helper_test cache
+
+test_expect_success 'when $XDG_RUNTIME_DIR is set, `$XDG_RUNTIME_DIR/git` are used' '
+	test_path_is_missing "/tmp/git-$(id -u)/git/credential-cache.sock" &&
+	test -S "$HOME/xdg_runtime/git/credential-cache.sock"
+'