fixes #2594

compiler/semtypes.nim

@@ -986,8 +986,11 @@ proc semProcTypeNode(c: PContext, n, genericParams: PNode,
         if r.sym == nil or sfAnon notin r.sym.flags:
           let lifted = liftParamType(c, kind, genericParams, r, "result",
                                      n.sons[0].info)
-          if lifted != nil: r = lifted
-          r.flags.incl tfRetType
+          if lifted != nil:
+            r = lifted
+            #if r.kind != tyGenericParam:
+            #echo "came here for ", typeToString(r)
+            r.flags.incl tfRetType
         r = skipIntLit(r)
         if kind == skIterator:
           # see tchainediterators

tests/metatype/tprocbothmeta.nim

@@ -1,5 +1,5 @@
 
-proc myFun[A,B](x: A): B =
+proc myFun[A](x: A): auto =
   result = float(x+10)
 
 proc myMap[T,S](sIn: seq[T], f: proc (q: T): S): seq[S] =

tests/metatype/tunresolved_return_type.nim

@@ -0,0 +1,20 @@
+discard """
+  errormsg: "cannot instantiate: 'T'"
+  line: 12
+"""
+
+# bug #2594
+
+
+type
+  ResultValue* = int64
+
+proc toNumber[T: int|uint|int64|uint64](v: ResultValue): T =
+  if v < low(T) or v > high(T):
+    raise newException(RangeError, "protocol error")
+  return T(v)
+
+#proc toNumber[T](v: int32): T =
+#  return (v)
+
+echo toNumber(23)