SI-6548 reflection now correctly enters jinners

When completing Java classes, runtime reflection enumerates their
fields, methods, constructors and inner classes, loads them and
enters them into either the instance part (ClassSymbol) or the
static part (ModuleSymbol).

However unlike fields, methods and constructors, inner classes don't
need to be entered explicitly - they are entered implicitly when
being loaded.

This patch fixes the double-enter problem, make sure that enter-on-load
uses the correct owner, and also hardens jclassAsScala against double
enters that can occur in a different scenario.

Since the fix is about Java-compiled classes, the test needs *.class
artifacts produced by javac. Therefore I updated javac-artifacts.jar to
include the new artifacts along with their source code.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
index ab93d7033a..9f29d9a230 100644
--- a/src/reflect/scala/reflect/runtime/JavaMirrors.scala
+++ b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
@@ -676,9 +676,9 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
         def enter(sym: Symbol, mods: Int) =
           (if (jModifier.isStatic(mods)) module.moduleClass else clazz).info.decls enter sym
 
-        for (jinner <- jclazz.getDeclaredClasses) {
-          enter(jclassAsScala(jinner, clazz), jinner.getModifiers)
-        }
+        for (jinner <- jclazz.getDeclaredClasses)
+          jclassAsScala(jinner) // inner class is entered as a side-effect
+                                // no need to call enter explicitly
 
         pendingLoadActions = { () =>
 
@@ -1036,14 +1036,14 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
      *  @param jclazz  The Java class
      *  @return A Scala class symbol that wraps all reflection info of `jclazz`
      */
-    private def jclassAsScala(jclazz: jClass[_]): Symbol = jclassAsScala(jclazz, sOwner(jclazz))
+    private def jclassAsScala(jclazz: jClass[_]): ClassSymbol =
+      toScala(classCache, jclazz)(_ jclassAsScala1 _)
 
-    private def jclassAsScala(jclazz: jClass[_], owner: Symbol): ClassSymbol = {
+    private def jclassAsScala1(jclazz: jClass[_]): ClassSymbol = {
+      val owner = sOwner(jclazz)
       val name = scalaSimpleName(jclazz)
       val completer = (clazz: Symbol, module: Symbol) => new FromJavaClassCompleter(clazz, module, jclazz)
-      val (clazz, module) = createClassModule(owner, name, completer)
-      classCache enter (jclazz, clazz)
-      clazz
+      createClassModule(owner, name, completer) match { case (clazz, module) => clazz }
     }
 
     /**