Merge pull request #12135 from dotty-staging/fix-12127

Normalize before querying for tuple component types

Author: odersky

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -118,7 +118,7 @@ object Applications {
   }
 
   def tupleComponentTypes(tp: Type)(using Context): List[Type] =
-    tp.widenExpr.dealias match
+    tp.widenExpr.dealias.normalized match
     case tp: AppliedType =>
       if defn.isTupleClass(tp.tycon.typeSymbol) then
         tp.args

compiler/test/dotc/pos-test-pickling.blacklist

@@ -36,6 +36,7 @@ i11236.scala
 i11247.scala
 i11250
 i9999.scala
+i12127.scala
 
 # Opaque type
 i5720.scala

tests/pos/i12127.scala

@@ -0,0 +1,5 @@
+val x = Option((1, 2, 3)).map(_ + _ + _)
+def foo[T <: Tuple : Tuple.IsMappedBy[Option]](t: T)(f: Tuple.InverseMap[T, Option] => Int) = null
+val y = foo(Option(1), Option(2), Option(3))(_ + _ + _)
+
+//val x: (Tuple3[Int, Int, Int] => Int) = _ + _ + _