Mapping over a SelectionProto should give a SelectionProto, not a RefinedType.

2 files changed, 9 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/core/Definitions.scala b/src/dotty/tools/dotc/core/Definitions.scala
index 6f6442208..64441486d 100644
--- a/src/dotty/tools/dotc/core/Definitions.scala
+++ b/src/dotty/tools/dotc/core/Definitions.scala
@@ -284,7 +284,7 @@ class Definitions(implicit ctx: Context) {
       lazy val targs = ft.typeArgs
       if ((FunctionClasses contains tsym) &&
           (targs.length - 1 <= MaxFunctionArity) &&
-          (FunctionClass(targs.length - 1) == tsym)) Some(targs.init, targs.last)
+          (FunctionClass(targs.length - 1) == tsym)) Some((targs.init, targs.last)) // Dotty deviation: no auto-tupling
       else None
     }
   }
diff --git a/src/dotty/tools/dotc/typer/Inferencing.scala b/src/dotty/tools/dotc/typer/Inferencing.scala
index fbc604db9..cbfe12abb 100644
--- a/src/dotty/tools/dotc/typer/Inferencing.scala
+++ b/src/dotty/tools/dotc/typer/Inferencing.scala
@@ -76,6 +76,14 @@ object Inferencing {
         mbr.exists && mbr.hasAltWith(m => normalizedCompatible(m.info, proto))
       }
     override def toString = "Proto" + super.toString
+    override def derivedRefinedType(parent: Type, refinedName: Name, refinedInfo: Type)(implicit ctx: Context): RefinedType = {
+      val tp1 @ RefinedType(parent1, refinedName1) = super.derivedRefinedType(parent, refinedName, refinedInfo)
+      if (tp1 eq this) this
+      else {
+        assert(parent == WildcardType)
+        new SelectionProto(refinedName1, tp1.refinedInfo)
+      }
+    }
   }
 
   /** Create a selection proto-type, but only one level deep;