Merge pull request #4286 from retronym/ticket/9131

SI-9131 Fix use of apply syntactic sugar with by-name param

3 files changed, 14 insertions, 18 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 2dd79075ee..e883bacc88 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -918,24 +918,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
       def insertApply(): Tree = {
         assert(!context.inTypeConstructorAllowed, mode) //@M
         val adapted = adaptToName(tree, nme.apply)
-        def stabilize0(pre: Type): Tree = stabilize(adapted, pre, MonoQualifierModes, WildcardType)
-
-        // TODO reconcile the overlap between Typers#stablize and TreeGen.stabilize
-        val qual = adapted match {
-          case This(_) =>
-            gen.stabilize(adapted)
-          case Ident(_) =>
-            val owner = adapted.symbol.owner
-            val pre =
-              if (owner.isPackageClass) owner.thisType
-              else if (owner.isClass) context.enclosingSubClassContext(owner).prefix
-              else NoPrefix
-            stabilize0(pre)
-          case Select(qualqual, _) =>
-            stabilize0(qualqual.tpe)
-          case other =>
-            other
-        }
+        val qual = gen.stabilize(adapted)
         typedPos(tree.pos, mode, pt) {
           Select(qual setPos tree.pos.makeTransparent, nme.apply)
         }
diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 4657fa0000..7ad5fdf096 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -128,6 +128,7 @@ abstract class TreeInfo {
        symOk(tree.symbol)
     && tree.symbol.isStable
     && !definitions.isByNameParamType(tree.tpe)
+    && !definitions.isByName(tree.symbol)
     && (allowVolatile || !tree.symbol.hasVolatileType) // TODO SPEC: not required by spec
   )
 
diff --git a/test/files/pos/t9131.scala b/test/files/pos/t9131.scala
new file mode 100644
index 0000000000..1a186a0a24
--- /dev/null
+++ b/test/files/pos/t9131.scala
@@ -0,0 +1,12 @@
+class Test {
+
+  def byNameFunc(f: (=> (() => Any)) => Any): Unit = ()
+
+  def test = {
+    // "value apply is not a member of => () => Any"
+    byNameFunc(z => z())
+    // okay
+    byNameFunc(z => z.apply())
+    byNameFunc(z => {val f = z; f()})
+  }
+}