8 files changed, 41 insertions, 12 deletions
diff --git a/src/actors/scala/actors/remote/Proxy.scala b/src/actors/scala/actors/remote/Proxy.scala
index 73af1edeec..43a43ac99c 100644
--- a/src/actors/scala/actors/remote/Proxy.scala
+++ b/src/actors/scala/actors/remote/Proxy.scala
@@ -118,7 +118,7 @@ private[remote] case class Apply0(rfun: Function2[AbstractActor, Proxy, Unit])
  */
 private[remote] class DelegateActor(creator: Proxy, node: Node, name: Symbol, kernel: NetKernel) extends Actor {
   var channelMap = new mutable.HashMap[Symbol, OutputChannel[Any]]
-  var sessionMap = new mutable.HashMap[OutputChannel[Any], Symbol]
+  var sessionMap = new mutable.HashMap[OutputChannel[_], Symbol]
 
   def act() {
     Actor.loop {
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
index ab19660da5..2be031a66f 100644
--- a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
+++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
@@ -500,11 +500,6 @@ trait MatchTranslation {
     // U must have N members _1,..., _N -- the _i are type checked, call their type Ti,
     // for now only used for case classes -- pretending there's an unapplyProd that's the identity (and don't call it)
     class ExtractorCallProd(val fun: Tree, val args: List[Tree]) extends ExtractorCall {
-      // TODO: fix the illegal type bound in pos/t602 -- type inference messes up before we get here:
-      /*override def equals(x$1: Any): Boolean = ...
-             val o5: Option[com.mosol.sl.Span[Any]] =  // Span[Any] --> Any is not a legal type argument for Span!
-      */
-
       private def constructorTp = fun.tpe
 
       def isTyped    = fun.isTyped
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
index 38a3f18bf8..df4dd3d777 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
@@ -322,7 +322,13 @@ trait PatternTypers {
      *
      * see test/files/../t5189*.scala
      */
-    private def convertToCaseConstructor(tree: Tree, caseClass: Symbol, pt: Type): Tree = {
+    private def convertToCaseConstructor(tree: Tree, caseClass: Symbol, ptIn: Type): Tree = {
+      // Unsoundness looms for those who infer type parameters with pt=Any. See SI-7886.
+      val pt = (
+        if (ptIn =:= AnyTpe && caseClass.typeParams.nonEmpty)
+          devWarningResult(s"Evading kind-polymorphic expected type for case constructor of $caseClass")(caseClass.tpe_*)
+        else ptIn
+      )
       val variantToSkolem     = new VariantToSkolemMap
       val caseConstructorType = tree.tpe.prefix memberType caseClass memberType caseClass.primaryConstructor
       val tree1               = TypeTree(caseConstructorType) setOriginal tree
diff --git a/test/files/neg/t4818.check b/test/files/neg/t4818.check
index a5e15e456b..8a2c024b30 100644
--- a/test/files/neg/t4818.check
+++ b/test/files/neg/t4818.check
@@ -1,6 +1,6 @@
 t4818.scala:4: error: type mismatch;
  found   : Int(5)
- required: Nothing
+ required: A
 	def f(x: Any) = x match { case Fn(f) => f(5) }
                                                   ^
 one error found
diff --git a/test/files/neg/t5189.check b/test/files/neg/t5189.check
index 7762f465dc..aecc1d11c4 100644
--- a/test/files/neg/t5189.check
+++ b/test/files/neg/t5189.check
@@ -1,6 +1,6 @@
 t5189.scala:3: error: type mismatch;
- found   : Nothing => Any
+ found   : T => U
  required: Any => Any
   def f(x: Any): Any => Any = x match { case Foo(bar) => bar }
                                                          ^
-one error found
-\ No newline at end of file
+one error found
diff --git a/test/files/neg/t6829.check b/test/files/neg/t6829.check
index 7c3c66e0f2..c7c641844e 100644
--- a/test/files/neg/t6829.check
+++ b/test/files/neg/t6829.check
@@ -16,12 +16,12 @@ t6829.scala:49: error: not found: value nextState
         val (s,a,s2) = (state,actions(agent),nextState)
                                              ^
 t6829.scala:50: error: type mismatch;
- found   : s.type (with underlying type Any)
+ found   : s.type (with underlying type T1)
  required: _53.State where val _53: G
         val r = rewards(agent).r(s,a,s2)
                                  ^
 t6829.scala:51: error: type mismatch;
- found   : s.type (with underlying type Any)
+ found   : s.type (with underlying type T1)
  required: _50.State
         agent.learn(s,a,s2,r): G#Agent
                     ^
diff --git a/test/files/neg/t7886.check b/test/files/neg/t7886.check
new file mode 100644
index 0000000000..338eee9708
--- /dev/null
+++ b/test/files/neg/t7886.check
@@ -0,0 +1,6 @@
+t7886.scala:10: error: type mismatch;
+ found   : Contra[A]
+ required: Contra[Any]
+    case Unravel(m, msg) => g(m)
+                              ^
+one error found
diff --git a/test/files/neg/t7886.scala b/test/files/neg/t7886.scala
new file mode 100644
index 0000000000..55d80a0a43
--- /dev/null
+++ b/test/files/neg/t7886.scala
@@ -0,0 +1,22 @@
+trait Covariant[+A]
+trait Contra[-A] { def accept(p: A): Unit }
+trait Invariant[A] extends Covariant[A] with Contra[A]
+
+case class Unravel[A](m: Contra[A], msg: A)
+
+object Test extends Covariant[Any] {
+  def g(m: Contra[Any]): Unit = m accept 5
+  def f(x: Any): Unit = x match {
+    case Unravel(m, msg) => g(m)
+    case _               =>
+  }
+  def main(args: Array[String]) {
+    f(Unravel[String](new Contra[String] { def accept(x: String) = x.length }, ""))
+  }
+}
+// java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
+//   at Test$$anon$1.accept(a.scala:18)
+//   at Test$.g(a.scala:13)
+//   at Test$.f(a.scala:15)
+//   at Test$.main(a.scala:18)
+//   at Test.main(a.scala)