I'm going to assume the patch I dropped off fiv...

I'm going to assume the patch I dropped off five months ago for #3938
was merely overlooked. Fixes an issue with java types which extend inner
classes. Closes #3938, review by odersky.

3 files changed, 17 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 7ba561136d..fb8b0058eb 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -4267,7 +4267,7 @@ trait Typers extends Modes {
       val result = typed(tree, forTypeMode(mode) | FUNmode, WildcardType)
 
       val restpe = result.tpe.normalize // normalize to get rid of type aliases for the following check (#1241)
-      if (!phase.erasedTypes && restpe.isInstanceOf[TypeRef] && !restpe.prefix.isStable) {
+      if (!phase.erasedTypes && restpe.isInstanceOf[TypeRef] && !restpe.prefix.isStable && !context.unit.isJava) {
         error(tree.pos, restpe.prefix+" is not a legal prefix for a constructor")
       }
 
diff --git a/test/files/bug3938/Parent.java b/test/files/bug3938/Parent.java
new file mode 100644
index 0000000000..08fae330bb
--- /dev/null
+++ b/test/files/bug3938/Parent.java
@@ -0,0 +1,9 @@
+public class Parent<A>{
+    class I1 {}
+    class I2 extends Parent.I1 {}
+
+    // OKAY:
+    class I3 extends I1 {}
+    static class I4 {}
+    static class I5 extends Parent.I4 {}
+}
diff --git a/test/files/bug3938/UseParent.scala b/test/files/bug3938/UseParent.scala
new file mode 100644
index 0000000000..685d1a03a8
--- /dev/null
+++ b/test/files/bug3938/UseParent.scala
@@ -0,0 +1,7 @@
+object UseParent {
+  classOf[Parent[AnyRef]#I2]
+
+  // OKAY
+  classOf[Parent[AnyRef]#I3]
+  classOf[Parent.I5]
+}