credential-cache: add tests for XDG functionality

Signed-off-by: Devin Lehmacher <lehmacdj@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0301-credential-cache.sh

@@ -12,7 +12,100 @@ test -z "$NO_UNIX_SOCKETS" || {
 # don't leave a stale daemon running
 trap 'code=$?; git credential-cache exit; (exit $code); die' EXIT
 
+# test that the daemon works with no special setup
 helper_test cache
+
+test_expect_success 'socket defaults to ~/.cache/git/credential/socket' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir -p .cache/git/credential/
+	" &&
+	test_path_is_missing "$HOME/.git-credential-cache" &&
+	test -S "$HOME/.cache/git/credential/socket"
+'
+
+XDG_CACHE_HOME="$HOME/xdg"
+export XDG_CACHE_HOME
+# test behavior when XDG_CACHE_HOME is set
+helper_test cache
+
+test_expect_success "use custom XDG_CACHE_HOME if set and default sockets are not created" '
+	test_when_finished "git credential-cache exit" &&
+	test -S "$XDG_CACHE_HOME/git/credential/socket" &&
+	test_path_is_missing "$HOME/.git-credential-cache/socket" &&
+	test_path_is_missing "$HOME/.cache/git/credential/socket"
+'
+unset XDG_CACHE_HOME
+
+test_expect_success 'credential-cache --socket option overrides default location' '
+	test_when_finished "
+		git credential-cache exit --socket \"\$HOME/dir/socket\" &&
+		rmdir \"\$HOME/dir\"
+	" &&
+	check approve "cache --socket \"\$HOME/dir/socket\"" <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/dir/socket"
+'
+
+test_expect_success "use custom XDG_CACHE_HOME even if xdg socket exists" '
+	test_when_finished "
+		git credential-cache exit &&
+		sane_unset XDG_CACHE_HOME
+	" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.cache/git/credential/socket" &&
+	XDG_CACHE_HOME="$HOME/xdg" &&
+	export XDG_CACHE_HOME &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$XDG_CACHE_HOME/git/credential/socket"
+'
+
+test_expect_success 'use user socket if user directory exists' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir \"\$HOME/.git-credential-cache/\"
+	" &&
+	mkdir -p -m 700 "$HOME/.git-credential-cache/" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.git-credential-cache/socket"
+'
+
+test_expect_success SYMLINKS 'use user socket if user directory is a symlink to a directory' '
+	test_when_finished "
+		git credential-cache exit &&
+		rmdir \"\$HOME/dir/\" &&
+		rm \"\$HOME/.git-credential-cache\"
+	" &&
+	mkdir -p -m 700 "$HOME/dir/" &&
+	ln -s "$HOME/dir" "$HOME/.git-credential-cache" &&
+	check approve cache <<-\EOF &&
+	protocol=https
+	host=example.com
+	username=store-user
+	password=store-pass
+	EOF
+	test -S "$HOME/.git-credential-cache/socket"
+'
+
 helper_test_timeout cache --timeout=1
 
 # we can't rely on our "trap" above working after test_done,