SI-9097 Remove spurious warning about conflicting filenames

When using delambdafy:method, closure classes are generated late.
The class is added to a map and integrated into the PackageDef in
transformStats.

When declaring a package object, there are potentially multiple
PackageDefs for the same package. In this case, the closure class
was added to all of them. As a result, GenASM / GenBCode would run
multiple times on the closure class. In GenBCode this would trigger
a warning about conflicting filenames.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
index d2c511a2d1..1f832ba81e 100644
--- a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
+++ b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala
@@ -113,7 +113,9 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre
     // after working on the entire compilation until we'll have a set of
     // new class definitions to add to the top level
     override def transformStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = {
-      super.transformStats(stats, exprOwner) ++ lambdaClassDefs(exprOwner)
+      // Need to remove from the lambdaClassDefs map: there may be multiple PackageDef for the same
+      // package when defining a package object. We only add the lambda class to one. See SI-9097.
+      super.transformStats(stats, exprOwner) ++ lambdaClassDefs.remove(exprOwner).getOrElse(Nil)
     }
 
     private def optionSymbol(sym: Symbol): Option[Symbol] = if (sym.exists) Some(sym) else None