SI-5390 Detect forward reference of case class apply

Refchecks performs (among others) two tasks at once:

  - detecting forward references
  - translating `qual.Case(...)` to `new qual.Case(...)`

As is often the case with such multi-tasking tree traversals,
completion of one task precluded the other.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 78ec6508ed..15ac3d134f 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1534,8 +1534,14 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
         sym.name == nme.apply &&
         isClassTypeAccessible(tree)
 
-      if (doTransform)
+      if (doTransform) {
+        tree foreach {
+          case i@Ident(_) =>
+            enterReference(i.pos, i.symbol) // SI-5390 need to `enterReference` for `a` in `a.B()`
+          case _ =>
+        }
         toConstructor(tree.pos, tree.tpe)
+      }
       else {
         ifNot
         tree