Add test for overloading and NULL

Examples/test-suite/common.mk

@@ -340,6 +340,7 @@ CPP_TEST_CASES += \
 	overload_extend \
 	overload_method \
 	overload_numeric \
+	overload_null \
 	overload_polymorphic \
 	overload_rename \
 	overload_return_type \

Examples/test-suite/overload_null.i

@@ -0,0 +1,52 @@
+%module overload_null
+
+%{
+struct F {};
+%}
+
+%inline %{
+struct X {};
+struct Y {};
+struct F;
+
+struct Overload {
+  int byval1(X x) { return 1; }
+  int byval1(Y* y) { return 2; }
+
+  int byval2(Y* y) { return 3; }
+  int byval2(X x) { return 4; }
+
+  int byref1(X& x) { return 5; }
+  int byref1(Y* y) { return 6; }
+
+  int byref2(Y* y) { return 7; }
+  int byref2(X& x) { return 8; }
+
+  int byconstref1(const X& x) { return 9; }
+  int byconstref1(Y* y) { return 10; }
+
+  int byconstref2(Y* y) { return 11; }
+  int byconstref2(const X& x) { return 12; }
+
+  // const pointer references
+  int byval1cpr(X x) { return 13; }
+  int byval1cpr(Y*const& y) { return 14; }
+
+  int byval2cpr(Y*const& y) { return 15; }
+  int byval2cpr(X x) { return 16; }
+
+  // forward class declaration
+  int byval1forwardptr(X x) { return 17; }
+  int byval1forwardptr(F* f) { return 18; }
+
+  int byval2forwardptr(F* f) { return 19; }
+  int byval2forwardptr(X x) { return 20; }
+
+  int byval1forwardref(X x) { return 21; }
+  int byval1forwardref(F& f) { return -21; }
+
+  int byval2forwardref(F& f) { return -22; }
+  int byval2forwardref(X x) { return 22; }
+
+};
+%}

Examples/test-suite/python/overload_null_runme.py

@@ -0,0 +1,44 @@
+from overload_null import *
+
+def check(a, b):
+    if a != b:
+        raise RuntimeError(str(a) + " does not equal " + str(b))
+
+o = Overload()
+x = X()
+
+check(1, o.byval1(x))
+check(2, o.byval1(None))
+
+check(3, o.byval2(None))
+check(4, o.byval2(x))
+
+check(5, o.byref1(x))
+check(6, o.byref1(None))
+
+check(7, o.byref2(None))
+check(8, o.byref2(x))
+
+check(9, o.byconstref1(x))
+check(10, o.byconstref1(None))
+
+check(11, o.byconstref2(None))
+check(12, o.byconstref2(x))
+
+# const pointer references
+check(13, o.byval1cpr(x))
+check(14, o.byval1cpr(None))
+
+check(15, o.byval2cpr(None))
+check(16, o.byval2cpr(x))
+
+# forward class declaration
+check(17, o.byval1forwardptr(x))
+check(18, o.byval1forwardptr(None))
+
+check(19, o.byval2forwardptr(None))
+check(20, o.byval2forwardptr(x))
+
+check(21, o.byval1forwardref(x))
+
+check(22, o.byval2forwardref(x))