7 files changed, 59 insertions, 6 deletions
diff --git a/src/library/scala/StringContext.scala b/src/library/scala/StringContext.scala
index f72547724d..8be0cb1619 100644
--- a/src/library/scala/StringContext.scala
+++ b/src/library/scala/StringContext.scala
@@ -120,7 +120,7 @@ case class StringContext(parts: String*) {
     val bldr = new java.lang.StringBuilder(process(pi.next()))
     while (ai.hasNext) {
       bldr append ai.next
-      bldr append treatEscapes(pi.next())
+      bldr append process(pi.next())
     }
     bldr.toString
   }
diff --git a/src/library/scala/concurrent/package.scala b/src/library/scala/concurrent/package.scala
index f7c732b851..3e849f1722 100644
--- a/src/library/scala/concurrent/package.scala
+++ b/src/library/scala/concurrent/package.scala
@@ -29,13 +29,12 @@ package object concurrent {
    */
   def future[T](body: =>T)(implicit execctx: ExecutionContext): Future[T] = Future[T](body)
 
-  /** Creates a promise object which can be completed with a value.
+  /** Creates a promise object which can be completed with a value or an exception.
    *  
    *  @tparam T       the type of the value in the promise
-   *  @param execctx  the execution context on which the promise is created on
    *  @return         the newly created `Promise` object
    */
-  def promise[T]()(implicit execctx: ExecutionContext): Promise[T] = Promise[T]()
+  def promise[T](): Promise[T] = Promise[T]()
 
   /** Used to designate a piece of code which potentially blocks, allowing the current [[BlockContext]] to adjust
    *  the runtime's behavior.
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala
index 53b40da8f6..b8f5e73acb 100644
--- a/src/reflect/scala/reflect/internal/Trees.scala
+++ b/src/reflect/scala/reflect/internal/Trees.scala
@@ -482,6 +482,10 @@ trait Trees extends api.Trees { self: SymbolTable =>
 
   case class TypeTree() extends TypTree with TypeTreeContextApi {
     private var orig: Tree = null
+    /** Was this type tree originally empty? That is, does it now contain
+      * an inferred type that must be forgotten in `resetAttrs` to
+      * enable retyping.
+      */
     private[scala] var wasEmpty: Boolean = false
 
     override def symbol = typeTreeSymbol(this) // if (tpe == null) null else tpe.typeSymbol
@@ -502,6 +506,15 @@ trait Trees extends api.Trees { self: SymbolTable =>
       wasEmpty = isEmpty
       setType(tp)
     }
+
+    override private[scala] def copyAttrs(tree: Tree) = {
+      super.copyAttrs(tree)
+      tree match {
+        case other: TypeTree => wasEmpty = other.wasEmpty // SI-6648 Critical for correct operation of `resetAttrs`.
+        case _ =>
+      }
+      this
+    }
   }
   object TypeTree extends TypeTreeExtractor
 
diff --git a/test/files/pos/t6648.scala b/test/files/pos/t6648.scala
new file mode 100644
index 0000000000..9593ebfee9
--- /dev/null
+++ b/test/files/pos/t6648.scala
@@ -0,0 +1,24 @@
+abstract class Node extends NodeSeq
+trait NodeSeq extends Seq[Node]
+object NodeSeq {
+  implicit def seqToNodeSeq(ns: Seq[Node]): NodeSeq = ???
+   def foo[B, That](f: Seq[B])(implicit bf: scala.collection.generic.CanBuildFrom[Seq[Int], B, That]): That = ???
+}
+
+class Transformer {
+  def apply(nodes: Any): Any = ???
+}
+
+object transformer1 extends Transformer {
+  // Adding explicit type arguments, or making the impilcit view
+  // seqToNodeSeq explicit avoids the crash
+  NodeSeq.foo {
+    // These both avoid the crash:
+    // val t = new Transformer {}; t.apply(null)
+    // new Transformer().apply(null)
+    new Transformer {}.apply(null)
+
+    null: NodeSeq
+  }: NodeSeq
+}
+
diff --git a/test/files/run/rawstrings.check b/test/files/run/rawstrings.check
index 36e63594df..2b6c40725a 100644
--- a/test/files/run/rawstrings.check
+++ b/test/files/run/rawstrings.check
@@ -1 +1 @@
-[\n\t'"$]
+[\n\t'"$\n]
diff --git a/test/files/run/rawstrings.scala b/test/files/run/rawstrings.scala
index 9df64f6625..b4d6e0c40a 100644
--- a/test/files/run/rawstrings.scala
+++ b/test/files/run/rawstrings.scala
@@ -1,3 +1,3 @@
 object Test extends App {
-  println(raw"[\n\t'${'"'}$$]")
+  println(raw"[\n\t'${'"'}$$\n]")
 }
diff --git a/test/files/run/t6559.scala b/test/files/run/t6559.scala
new file mode 100644
index 0000000000..5c671f7275
--- /dev/null
+++ b/test/files/run/t6559.scala
@@ -0,0 +1,17 @@
+
+object Test {
+
+  def main(args: Array[String]) = {
+     val one = "1"
+     val two = "2"
+
+     val raw = raw"\n$one\n$two\n"
+     val escaped = s"\n$one\n$two\n"
+     val buggy = "\\n1\n2\n"
+     val correct = "\\n1\\n2\\n"
+
+     assert(raw != escaped, "Raw strings should not be escaped.")
+     assert(raw != buggy, "Raw strings after variables should not be escaped.")
+     assert(raw == correct, "Raw strings should stay raw.")
+  }
+}