SI-6666 Account for nesting in setting INCONSTRUCTOR

This flag is calcualed in Namers, and assigned to class
and module class symbols that are defined in self/super-calls,
and in early definitions.

For example, class D is INCONSTRUCTOR in each case below:

    class C extends Super({class D; ()})
    class C(a: Any) {
      def this(a: Any) = this({class D; ()})
    }
    new { val x = { class D; () } with Super(())

But, the calculation of this flag failed to account for
nesting, so it was not set in cases like:

    class C(a: Any) {
      def this(a: Any) = this({val x = {class D; ()}; x})
    }

This patch searches the enclosing context chain, rather than
just the immediate context. The search is terminated at the
first non term-owned context. In the following example, this
avoids marking `E` as INCONSTRUCTOR; only `D` should be.

    class C extends Super({class D { class E }; ()})

This closes SI-6259 and SI-6506, and fixes one problem
in the recently reopened SI-6957.

5 files changed, 39 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index 98b6264051..967a3214f2 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -123,9 +123,12 @@ trait Namers extends MethodSynthesis {
     def setPrivateWithin(tree: MemberDef, sym: Symbol): Symbol =
       setPrivateWithin(tree, sym, tree.mods)
 
-    def inConstructorFlag: Long =
-      if (owner.isConstructor && !context.inConstructorSuffix || owner.isEarlyInitialized) INCONSTRUCTOR
-      else 0l
+    def inConstructorFlag: Long = {
+      val termOwnedContexts: List[Context] = context.enclosingContextChain.takeWhile(_.owner.isTerm)
+      val constructorNonSuffix = termOwnedContexts exists (c => c.owner.isConstructor && !c.inConstructorSuffix)
+      val earlyInit            = termOwnedContexts exists (_.owner.isEarlyInitialized)
+      if (constructorNonSuffix || earlyInit) INCONSTRUCTOR else 0L
+    }
 
     def moduleClassFlags(moduleFlags: Long) =
       (moduleFlags & ModuleToClassFlags) | inConstructorFlag
diff --git a/test/files/run/t6259.scala b/test/files/run/t6259.scala
index a5a7bf9043..294c95e96b 100644
--- a/test/files/run/t6259.scala
+++ b/test/files/run/t6259.scala
@@ -48,7 +48,7 @@ object Test extends App {
   val e = new E {}; e.F
   val g = new G; g.H
 
-  //locally(HasX.x)   TODO sort out VerifyError in HasX$InVal$2$.<init> by accounting for nesting in Namer#inConstructorFlag
+  locally(HasX.x)
   // locally(Early.x) TODO sort out VerifyError in Early$.<init>
   // DoubleOk         TODO sort out VerifyError in DoubleOk$.<init>
 }
diff --git a/test/files/run/t6506.scala b/test/files/run/t6506.scala
new file mode 100644
index 0000000000..04d77c3c16
--- /dev/null
+++ b/test/files/run/t6506.scala
@@ -0,0 +1,8 @@
+object Test {
+  def main(args: Array[String]) {
+    new WL(new {} #:: S) with T
+  }
+  object S { def #::(a: Any): Any = () }
+  trait T
+  class WL(a: Any)
+}
diff --git a/test/files/run/t6666a.scala b/test/files/run/t6666a.scala
new file mode 100644
index 0000000000..1d208a32e7
--- /dev/null
+++ b/test/files/run/t6666a.scala
@@ -0,0 +1,16 @@
+class A(a: Any)
+
+object Test {
+  def main(args: Array[String]): Unit = {
+  }
+
+  val x: Unit = {
+    object InVal extends A({
+      new {}           // okay
+      val o = {new {}} // nesting triggers a VerifyError.
+      null
+    });
+    InVal;
+    ()
+  };
+}
diff --git a/test/files/run/t6957.scala b/test/files/run/t6957.scala
new file mode 100644
index 0000000000..d0bf8e7b5e
--- /dev/null
+++ b/test/files/run/t6957.scala
@@ -0,0 +1,8 @@
+object Test {
+  def main(args: Array[String]) {
+    class Foo
+    class Parent(f:Foo)
+    class Child extends Parent({val x=new Foo{}; x})
+    new Child
+  }
+}