Following up on things that -Xlint told me, som...

Following up on things that -Xlint told me, sometimes because Mr. Linty
was being sensible and other times just to shut him up so we can hear
better in the future.

- made xml.Equality public because it occurs in public method signatures
- made some actor classes with inaccessible-unoverridable methods final
- eliminated a bunch of "dead code follows" warnings by deleting the
dead code which really did follow - improved the reliability of warnings
about inaccessible types

For the changes in actors, review by phaller.

4 files changed, 18 insertions, 10 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Adaptations.scala b/src/compiler/scala/tools/nsc/typechecker/Adaptations.scala
index 3dee4650de..99d5363d5e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Adaptations.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Adaptations.scala
@@ -59,6 +59,7 @@ trait Adaptations {
         // an opt-in compiler option is given.
         oneArgObject && !(
              isStringAddition(t.symbol)
+          || isArrowAssoc(t.symbol)
           || t.symbol.name == nme.equals_
           || t.symbol.name == nme.EQ
           || t.symbol.name == nme.NE
diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 765881ac81..097bbf5915 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -219,7 +219,7 @@ trait Implicits {
   object Function1 {
     val Sym = FunctionClass(1)
     def unapply(tp: Type) = tp match {
-      case TypeRef(_, Sym, arg1 :: arg2 :: _) => Some(arg1, arg2)
+      case TypeRef(_, Sym, arg1 :: arg2 :: _) => Some((arg1, arg2))
       case _                                  => None
     }
   }
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 8e1ee97387..37b5870ac5 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1221,22 +1221,27 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R
           otherSym.decodedName, cannot, memberSym.decodedName)
       )
     }
+
     /** Warn about situations where a method signature will include a type which
      *  has more restrictive access than the method itself.
      */
     private def checkAccessibilityOfReferencedTypes(tree: Tree) {
       val member = tree.symbol
 
-      // types of the value parameters
-      member.paramss.flatten foreach { p =>
-        val normalized = p.tpe.normalize
-        if ((normalized ne p.tpe) && lessAccessibleSymsInType(normalized, member).isEmpty) ()
-        else lessAccessibleSymsInType(p.tpe, member) foreach (sym => warnLessAccessible(sym, member))
+      def checkAccessibilityOfType(tpe: Type) {
+        val inaccessible = lessAccessibleSymsInType(tpe, member)
+        // if the unnormalized type is accessible, that's good enough
+        if (inaccessible.isEmpty) ()
+        // or if the normalized type is, that's good too
+        else if ((tpe ne tpe.normalize) && lessAccessibleSymsInType(tpe.normalize, member).isEmpty) ()
+        // otherwise warn about the inaccessible syms in the unnormalized type
+        else inaccessible foreach (sym => warnLessAccessible(sym, member))
       }
+
+      // types of the value parameters
+      member.paramss.flatten foreach (p => checkAccessibilityOfType(p.tpe))
       // upper bounds of type parameters
-      member.typeParams.map(_.info.bounds.hi.widen) foreach { tp =>
-        lessAccessibleSymsInType(tp, member) foreach (sym => warnLessAccessible(sym, member))
-      }
+      member.typeParams.map(_.info.bounds.hi.widen) foreach checkAccessibilityOfType
     }
 
     /** Check that a deprecated val or def does not override a
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 4125ab0285..23482eb609 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2118,6 +2118,8 @@ trait Typers extends Modes with Adaptations {
               } else {
                 val localTyper = if (inBlock || (stat.isDef && !stat.isInstanceOf[LabelDef])) this
                                  else newTyper(context.make(stat, exprOwner))
+                // XXX this creates a spurious dead code warning if an exception is thrown
+                // in a constructor, even if it is the only thing in the constructor.
                 val result = checkDead(localTyper.typed(stat, EXPRmode | BYVALmode, WildcardType))
                 if (treeInfo.isSelfOrSuperConstrCall(result)) {
                   context.inConstructorSuffix = true
@@ -2202,7 +2204,7 @@ trait Typers extends Modes with Adaptations {
           }) ::: newStats.toList
         }
       }
-      val result = stats mapConserve (typedStat)
+      val result = stats mapConserve typedStat
       if (phase.erasedTypes) result
       else checkNoDoubleDefsAndAddSynthetics(result)
     }