3 files changed, 21 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/Settings.scala b/src/compiler/scala/tools/nsc/Settings.scala
index 8db03da28c..fe031ce15d 100644
--- a/src/compiler/scala/tools/nsc/Settings.scala
+++ b/src/compiler/scala/tools/nsc/Settings.scala
@@ -120,6 +120,7 @@ class Settings(error: String => unit) {
   val Xgadt         = BooleanSetting("-Xgadt", "enable gadt for classes")
   val Xlinearizer   = ChoiceSetting ("-Xlinearizer", "Linearizer to use", List("normal", "dfs", "rpo", "dump"), "rpo")
   val Xgenerics     = BooleanSetting("-Xgenerics", "Use generic Java types");
+  val Xprintpos     = BooleanSetting("-Xprintpos", "Print tree positions (as offsets)");
 
   /** A list of all settings */
   def allSettings: List[Setting] = allsettings.reverse
diff --git a/src/compiler/scala/tools/nsc/ast/TreePrinters.scala b/src/compiler/scala/tools/nsc/ast/TreePrinters.scala
index 137de920b9..cada6bdbc5 100644
--- a/src/compiler/scala/tools/nsc/ast/TreePrinters.scala
+++ b/src/compiler/scala/tools/nsc/ast/TreePrinters.scala
@@ -308,7 +308,8 @@ abstract class TreePrinters {
       }
     }
 
-    def print(tree: Tree): unit =
+    def print(tree: Tree): unit = {
+      if (settings.Xprintpos.value) print("["+tree.pos+"]")
       printRaw(
         if (tree.isDef && tree.symbol != NoSymbol) {
           tree match {
@@ -320,7 +321,8 @@ abstract class TreePrinters {
             case AliasTypeDef(_, _, _, rhs) => AliasTypeDef(tree.symbol, rhs)
             case _ => tree
           }
-        } else tree);
+        } else tree)
+    }
 
     def print(unit: CompilationUnit): unit = {
       print("// Scala source: " + unit.source + "\n")
diff --git a/test/files/pos/bug646.scala b/test/files/pos/bug646.scala
new file mode 100644
index 0000000000..d5d3471731
--- /dev/null
+++ b/test/files/pos/bug646.scala
@@ -0,0 +1,16 @@
+object xfor {
+
+  import scala.xml.NodeSeq
+
+    val books =
+    <bks>
+      <title>Blabla</title>
+      <title>Blubabla</title>
+      <title>Baaaaaaalabla</title>
+    </bks>;
+
+  new NodeSeq { val theSeq = books.child } match {
+    case t @ <title>Blabla</title> => t
+  }
+
+}