fixes #6393

compiler/procfind.nim

@@ -66,12 +66,10 @@ proc searchForProcOld*(c: PContext, scope: PScope, fn: PSym): PSym =
 proc searchForProcNew(c: PContext, scope: PScope, fn: PSym): PSym =
   const flags = {ExactGenericParams, ExactTypeDescValues,
                  ExactConstraints, IgnoreCC}
-
   var it: TIdentIter
-
   result = initIdentIter(it, scope.symbols, fn.name)
   while result != nil:
-    if result.kind == fn.kind and sameType(result.typ, fn.typ, flags):
+    if result.kind == fn.kind: #and sameType(result.typ, fn.typ, flags):
       case equalParams(result.typ.n, fn.typ.n)
       of paramsEqual:
         if (sfExported notin result.flags) and (sfExported in fn.flags):
@@ -85,11 +83,8 @@ proc searchForProcNew(c: PContext, scope: PScope, fn: PSym): PSym =
         return
       of paramsNotEqual:
         discard
-
     result = nextIdentIter(it, scope.symbols)
 
-  return nil
-
 proc searchForProc*(c: PContext, scope: PScope, fn: PSym): PSym =
   result = searchForProcNew(c, scope, fn)
   when false:

compiler/types.nim

@@ -777,8 +777,8 @@ proc equalParams(a, b: PNode): TParamsEquality =
         return paramsNotEqual # paramsIncompatible;
       # continue traversal! If not equal, we can return immediately; else
       # it stays incompatible
-    if not sameTypeOrNil(a.sons[0].typ, b.sons[0].typ, {ExactTypeDescValues}):
-      if (a.sons[0].typ == nil) or (b.sons[0].typ == nil):
+    if not sameTypeOrNil(a.typ, b.typ, {ExactTypeDescValues}):
+      if (a.typ == nil) or (b.typ == nil):
         result = paramsNotEqual # one proc has a result, the other not is OK
       else:
         result = paramsIncompatible # overloading by different

tests/errmsgs/tcant_overload_by_return_type.nim

@@ -0,0 +1,9 @@
+discard """
+errormsg: "overloaded 'x' leads to ambiguous calls"
+line: 9
+"""
+
+# bug #6393
+
+proc x(): int = 7
+proc x(): string = "strange"