Merge pull request #3666 from trustable-code/PR10

Fix multimethods issue #3550

compiler/cgmeth.nim

@@ -19,10 +19,7 @@ proc genConv(n: PNode, d: PType, downcast: bool): PNode =
   if (source.kind == tyObject) and (dest.kind == tyObject):
     var diff = inheritanceDiff(dest, source)
     if diff == high(int):
-      # see bug #3550 which triggers it. XXX This is a hack but I don't know yet
-      # how the real fix looks like:
-      localError(n.info, "there is no subtype relation between " &
-                 typeToString(d) & " and " & typeToString(n.typ))
+      # no subtype relation, nothing to do
       result = n
     elif diff < 0:
       result = newNodeIT(nkObjUpConv, n.info, d)

tests/method/tmultim8.nim

@@ -0,0 +1,19 @@
+
+# bug #3550
+
+type 
+  BaseClass = ref object of RootObj
+  Class1 = ref object of BaseClass
+  Class2 = ref object of BaseClass
+
+method test(obj: Class1, obj2: BaseClass) =
+  discard
+
+method test(obj: Class2, obj2: BaseClass) =
+  discard
+
+var obj1 = Class1()
+var obj2 = Class2()
+
+obj1.test(obj2) 
+obj2.test(obj1)