Merge commit '36967321c7' into merge-2.11.x-to-2.12.x-20170214

4 files changed, 12 insertions, 16 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index 1a4671e15f..9129478b41 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -663,10 +663,9 @@ abstract class ClassfileParser {
               // so have to check unsafeTypeParams.isEmpty before worrying about raw type case below,
               // or we'll create a boatload of needless existentials.
               else if (classSym.isMonomorphicType || classSym.unsafeTypeParams.isEmpty) tp
-              else debuglogResult(s"raw type from $classSym"){
+              else debuglogResult(s"raw type from $classSym") {
                 // raw type - existentially quantify all type parameters
-                val eparams = typeParamsToExistentials(classSym, classSym.unsafeTypeParams)
-                newExistentialType(eparams, typeRef(pre, classSym, eparams.map(_.tpeHK)))
+                classExistentialType(pre, classSym)
               }
             case tp =>
               assert(sig.charAt(index) != '<', s"sig=$sig, index=$index, tp=$tp")
diff --git a/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala b/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
index 6d883aee3d..7943187f35 100644
--- a/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
@@ -130,8 +130,9 @@ trait SyntheticMethods extends ast.TreeDSL {
      */
     def canEqualMethod: Tree = {
       syntheticCanEqual = true
-      createMethod(nme.canEqual_, List(AnyTpe), BooleanTpe)(m =>
-        Ident(m.firstParam) IS_OBJ classExistentialType(clazz))
+      createMethod(nme.canEqual_, List(AnyTpe), BooleanTpe) { m =>
+        Ident(m.firstParam) IS_OBJ classExistentialType(context.prefix, clazz)
+      }
     }
 
     /* that match { case _: this.C => true ; case _ => false }
diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala
index 19460af27f..9515309802 100644
--- a/src/reflect/scala/reflect/internal/Definitions.scala
+++ b/src/reflect/scala/reflect/internal/Definitions.scala
@@ -667,8 +667,8 @@ trait Definitions extends api.StandardDefinitions {
       isBundle && isBlackbox
     }
 
-    def isListType(tp: Type)     = tp <:< classExistentialType(ListClass)
-    def isIterableType(tp: Type) = tp <:< classExistentialType(IterableClass)
+    def isListType(tp: Type)     = tp.typeSymbol.isNonBottomSubClass(ListClass)
+    def isIterableType(tp: Type) = tp.typeSymbol.isNonBottomSubClass(IterableClass)
 
     // These "direct" calls perform no dealiasing. They are most needed when
     // printing types when one wants to preserve the true nature of the type.
@@ -980,14 +980,10 @@ trait Definitions extends api.StandardDefinitions {
      *
      *    C[E1, ..., En] forSome { E1 >: LB1 <: UB1 ... en >: LBn <: UBn }.
      */
-    // TODO Review the way this is used. I see two potential problems:
-    //  1. `existentialAbstraction` here doesn't create fresh existential type symbols, it just
-    //     uses the class type parameter symbols directly as the list of quantified symbols.
-    //     See SI-8244 for the trouble that this can cause.
-    //     Compare with callers of `typeParamsToExistentials` (used in Java raw type handling)
-    //  2. Why don't we require a prefix? Could its omission lead to wrong results in CheckabilityChecker?
-    def classExistentialType(clazz: Symbol): Type =
-      existentialAbstraction(clazz.typeParams, clazz.tpe_*)
+    def classExistentialType(prefix: Type, clazz: Symbol): Type = {
+      val eparams = typeParamsToExistentials(clazz, clazz.unsafeTypeParams)
+      newExistentialType(eparams, typeRef(prefix, clazz, eparams.map(_.tpeHK)))
+    }
 
     // members of class scala.Any
 
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index ad7e3ffe8f..a6b6b1356c 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -3944,7 +3944,7 @@ trait Types
    *        any corresponding non-variant type arguments of bt1 and bt2 are the same
    */
   def isPopulated(tp1: Type, tp2: Type): Boolean = {
-    def isConsistent(tp1: Type, tp2: Type): Boolean = (tp1, tp2) match {
+    def isConsistent(tp1: Type, tp2: Type): Boolean = (tp1.dealias, tp2.dealias) match {
       case (TypeRef(pre1, sym1, args1), TypeRef(pre2, sym2, args2)) =>
         assert(sym1 == sym2, (sym1, sym2))
         (    pre1 =:= pre2