SI-5789 Removes assertion about implclass flag in Mixin.scala

The assertion that the class being mixed from should be an implclass
seems reasonable, but the flag isn't always set. In order to stop the
bleeding this fix turns the assertion into a debug warning. Issue SI-6782
will track figuring out the root cause of the missing flag.

3 files changed, 31 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/Mixin.scala b/src/compiler/scala/tools/nsc/transform/Mixin.scala
index 64bb98e2c5..e59a70869f 100644
--- a/src/compiler/scala/tools/nsc/transform/Mixin.scala
+++ b/src/compiler/scala/tools/nsc/transform/Mixin.scala
@@ -269,7 +269,7 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL {
 
     /** Mix in members of implementation class mixinClass into class clazz */
     def mixinImplClassMembers(mixinClass: Symbol, mixinInterface: Symbol) {
-      assert(mixinClass.isImplClass, "Not an impl class:" +
+      if (!mixinClass.isImplClass) debugwarn ("Impl class flag is not set " +
         ((mixinClass.debugLocationString, mixinInterface.debugLocationString)))
 
       for (member <- mixinClass.info.decls ; if isForwarded(member)) {
@@ -360,7 +360,6 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL {
     // first complete the superclass with mixed in members
     addMixedinMembers(clazz.superClass, unit)
 
-    //Console.println("adding members of " + clazz.info.baseClasses.tail.takeWhile(superclazz !=) + " to " + clazz);//DEBUG
     for (mc <- clazz.mixinClasses ; if mc hasFlag lateINTERFACE) {
       // @SEAN: adding trait tracking so we don't have to recompile transitive closures
       unit.depends += mc
diff --git a/test/files/run/t5789.check b/test/files/run/t5789.check
new file mode 100644
index 0000000000..3c459e9a54
--- /dev/null
+++ b/test/files/run/t5789.check
@@ -0,0 +1 @@
+completed successfully
diff --git a/test/files/run/t5789.scala b/test/files/run/t5789.scala
new file mode 100644
index 0000000000..4169e34959
--- /dev/null
+++ b/test/files/run/t5789.scala
@@ -0,0 +1,29 @@
+
+import scala.tools.nsc._
+import interpreter.ILoop
+
+object Test {
+
+  def main(args : Array[String]) {
+
+    val code = """
+  val n = 2
+  () => n
+    """
+
+    val s = new Settings()
+    s.optimise.value = false
+    s.debug.value  = true
+    s.log.value = List("all")
+    val lines = ILoop.runForTranscript(code + "\n" + code, s).lines.toList
+
+
+    if (lines exists (_ contains "Abandoning crashed session")) {
+     lines foreach println
+    	println("crashed!")
+    } else {
+      println("completed successfully")
+    }
+  }
+}
+