Adapt type arguments in typedAppliedTypeTree

Previously, only pattern bound arguments were adapated. This was an oversight.
Also, change logix so that we survive empty type parameter lists. This was
also an oversight before.

1 files changed, 13 insertions, 11 deletions

diff --git a/src/dotty/tools/dotc/typer/Typer.scala b/src/dotty/tools/dotc/typer/Typer.scala
index 337737437..7caec5135 100644
--- a/src/dotty/tools/dotc/typer/Typer.scala
+++ b/src/dotty/tools/dotc/typer/Typer.scala
@@ -825,7 +825,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
     res
   }
 
-  def typedAppliedTypeTree(tree: untpd.AppliedTypeTree)(implicit ctx: Context): AppliedTypeTree = track("typedAppliedTypeTree") {
+  def typedAppliedTypeTree(tree: untpd.AppliedTypeTree)(implicit ctx: Context): Tree = track("typedAppliedTypeTree") {
     val tpt1 = typed(tree.tpt)
     val tparams = tpt1.tpe.typeParams
     var args = tree.args
@@ -833,17 +833,19 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
       ctx.error(d"${tpt1.tpe} does not take type parameters")
       tpt1
     }
-    else if (args.length != tparams.length) {
-      ctx.error(d"wrong number of type arguments for ${tpt1.tpe}, should be ${tparams.length}", tree.pos)
-      args = args.take(tparams.length)
+    else {
+      if (args.length != tparams.length) {
+        ctx.error(d"wrong number of type arguments for ${tpt1.tpe}, should be ${tparams.length}", tree.pos)
+        args = args.take(tparams.length)
+      }
+      def typedArg(arg: untpd.Tree, tparam: Symbol) = {
+        val arg1 = typed(arg, if (ctx.mode is Mode.Pattern) tparam.info else WildcardType)
+        adaptTypeArg(arg1, if (tparam.isCompleted) tparam.info else WildcardType)
+      }
+      val args1 = args.zipWithConserve(tparams)(typedArg(_, _)).asInstanceOf[List[Tree]]
+      // check that arguments conform to bounds is done in phase PostTyper
+      assignType(cpy.AppliedTypeTree(tree)(tpt1, args1), tpt1, args1)
     }
-    val argPts =
-      if (ctx.mode is Mode.Pattern) tpt1.tpe.typeParams.map(_.info)
-      else tree.args.map(_ => WildcardType)
-    def typedArg(arg: untpd.Tree, pt: Type) = adaptTypeArg(typed(arg, pt), pt)
-    val args1 = args.zipWithConserve(argPts)(typedArg(_, _)).asInstanceOf[List[Tree]]
-    // check that arguments conform to bounds is done in phase PostTyper
-    assignType(cpy.AppliedTypeTree(tree)(tpt1, args1), tpt1, args1)
   }
 
   def typedByNameTypeTree(tree: untpd.ByNameTypeTree)(implicit ctx: Context): ByNameTypeTree = track("typedByNameTypeTree") {