Add another quoted string test case.
diff --git a/shell_test.go b/shell_test.go
index 3d4b55b..c729410 100644
--- a/shell_test.go
+++ b/shell_test.go
@@ -68,6 +68,7 @@
 		{"''", []string{""}, true},
 		{"a ''", []string{"a", ""}, true},
 		{" a \"\" b ", []string{"a", "", "b"}, true},
+		{"'' a", []string{"", "a"}, true},
 
 		// Unbalanced quotation marks and escapes are detected.
 		{"\\", []string{""}, false},