Add extra test cases

cpp/ql/test/library-tests/dataflow/fields/constructors.cpp

@@ -0,0 +1,51 @@
+namespace Constructors
+{
+int user_input()
+{
+    return 42;
+}
+
+void sink(int x)
+{
+}
+
+class Foo
+{
+    int a_;
+    int b_;
+
+public:
+    int a() { return a_; }
+    int b() { return b_; }
+    void setA(int a) { a_ = a; }
+    void setB(int b) { b_ = b; }
+
+    Foo(int a, int b) : a_(a), b_(b){};
+};
+
+void bar(Foo &f)
+{
+    sink(f.a());
+    sink(f.b());
+}
+
+void foo()
+{
+    Foo f(user_input(), 0);
+    Foo g(0, user_input());
+    Foo h(user_input(), user_input());
+    Foo i(0, 0);
+
+    // Only a() should alert
+    bar(f);
+
+    // Only b() should alert
+    bar(g);
+
+    // Both a() and b() should alert
+    bar(h);
+
+    // Nothing should alert
+    bar(i);
+}
+}; // namespace Constructors