Merge pull request #15417 from dotty-staging/fix-15414

Allow for unqualified `apply` as context functions

Author: smarter

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

@@ -3982,22 +3982,26 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
 
     /** Convert constructor proxy reference to a new expression */
     def newExpr =
-      val Select(qual, nme.apply) = tree: @unchecked
-      val tycon = tree.tpe.widen.finalResultType.underlyingClassRef(refinementOK = false)
+      val qual = qualifier(tree)
       val tpt = qual match
         case Ident(name) =>
           cpy.Ident(qual)(name.toTypeName)
         case Select(pre, name) =>
           cpy.Select(qual)(pre, name.toTypeName)
         case qual: This if qual.symbol.is(ModuleClass) =>
           cpy.Ident(qual)(qual.symbol.name.sourceModuleName.toTypeName)
+      val tycon = tree.tpe.widen.finalResultType.underlyingClassRef(refinementOK = false)
       typed(
         untpd.Select(
           untpd.New(untpd.TypedSplice(tpt.withType(tycon))),
           nme.CONSTRUCTOR),
         pt)
         .showing(i"convert creator $tree -> $result", typr)
 
+    def isApplyProxy(tree: Tree) = tree match
+      case Select(_, nme.apply) => tree.symbol.isAllOf(ApplyProxyFlags)
+      case _ => false
+
     tree match {
       case _: MemberDef | _: PackageDef | _: Import | _: WithoutTypeOrPos[?] | _: Closure => tree
       case _ => tree.tpe.widen match {
@@ -4013,7 +4017,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
               adaptOverloaded(ref)
           }
         case poly: PolyType if !(ctx.mode is Mode.Type) =>
-          if tree.symbol.isAllOf(ApplyProxyFlags) then newExpr
+          if isApplyProxy(tree) then newExpr
           else if pt.isInstanceOf[PolyProto] then tree
           else
             var typeArgs = tree match
@@ -4027,7 +4031,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
             readaptSimplified(handleStructural(tree))
           else pt match {
             case pt: FunProto =>
-              if tree.symbol.isAllOf(ApplyProxyFlags) then newExpr
+              if isApplyProxy(tree) then newExpr
               else adaptToArgs(wtp, pt)
             case pt: PolyProto if !wtp.isImplicitMethod =>
               tryInsertApplyOrImplicit(tree, pt, locked)(tree) // error will be reported in typedTypeApply

tests/neg/i15414.scala

@@ -0,0 +1,4 @@
+class C()
+object C {
+  val c = apply() // error
+}