[backport] SI-9375 add synthetic readResolve only for static modules

For inner modules, the synthetic readResolve method would cause the
module constructor to be invoked on de-serialization in certain
situations. See the discussion in the ticket.

Adds a comprehensive test around serializing and de-serializing
modules.

1 files changed, 18 insertions, 0 deletions

diff --git a/test/files/pos/t6666d.scala b/test/files/pos/t6666d.scala
new file mode 100644
index 0000000000..49a688f91b
--- /dev/null
+++ b/test/files/pos/t6666d.scala
@@ -0,0 +1,18 @@
+
+import scala.collection.immutable.TreeMap
+import scala.math.Ordering
+
+class Test[K](param:TreeMap[K,Int]){
+  def this() = this({
+    implicit object TreeOrd extends Ordering[K](){
+      def compare(a: K, b: K) = {
+        -1
+      }
+    }
+    new TreeMap[K, Int]()
+  })
+}
+
+object Test extends App {
+  new Test()
+}