bash prompt: add a test for symbolic link symbolic refs

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>

t/t9903-bash-prompt.sh

@@ -40,6 +40,15 @@ test_expect_success 'prompt - branch name' '
 	test_cmp expected "$actual"
 '
 
+test_expect_success SYMLINKS 'prompt - branch name - symlink symref' '
+	printf " (master)" >expected &&
+	test_when_finished "git checkout master" &&
+	test_config core.preferSymlinkRefs true &&
+	git checkout master &&
+	__git_ps1 >"$actual" &&
+	test_cmp expected "$actual"
+'
+
 test_expect_success 'prompt - detached head' '
 	printf " ((%s...))" $(git log -1 --format="%h" b1^) >expected &&
 	git checkout b1^ &&