(1, x => 2): (Int, Int => Int) fails type checking the _2

[nicolasstucki]

dotty> (1, x => 2): (Int, Int => Int) 
    ^
(1, x => 2): (Int, Int => Int)
<console>:5: error: missing parameter type for parameter x, expected = T2

scala> (1, x => 2): (Int, Int => Int)
res0: (Int, Int => Int) = (1,<function1>)

This issue is related to #1366 and is probably a further refinement of fix #1371.

This code was executed with #1371.

[smarter]

I noticed that #1371 does not recursively call classBound in some cases, that might help (untested):

      def classBound(pt: Type): Type = pt.dealias.stripTypeVar match {
        case tref: TypeRef if !tref.symbol.isClass => classBound(tref.info.bounds.lo)
        case param: PolyParam =>
          ctx.typerState.constraint.entry(param) match {
            case TypeBounds(lo, hi) =>
              if (hi.classSymbol.isPrimitiveValueClass) hi //constrain further with high bound
-              else lo
+              else classBound(lo)
-           case NoType => param.binder.paramBounds(param.paramNum).lo
+           case NoType => classBound(param.binder.paramBounds(param.paramNum).lo)
            case inst => classBound(inst)
          }
        case pt => pt
}

[odersky]

@smarter I agree that classBound should be called recursively. But that did not fix the problem. In fact I don't think it's related to #1366, ad there are no constants coming in the picture.