4 files changed, 92 insertions, 67 deletions
diff --git a/src/dotty/tools/dotc/typer/Checking.scala b/src/dotty/tools/dotc/typer/Checking.scala
index 287e93c7a..ae325af2a 100644
--- a/src/dotty/tools/dotc/typer/Checking.scala
+++ b/src/dotty/tools/dotc/typer/Checking.scala
@@ -102,13 +102,14 @@ trait Checking {
       tp
   }
 
-  /** Check that class does not define */
+  /** Check that class does not define same symbol twice */
   def checkNoDoubleDefs(cls: Symbol)(implicit ctx: Context): Unit = {
     val seen = new mutable.HashMap[Name, List[Symbol]] {
       override def default(key: Name) = Nil
     }
     typr.println(i"check no double defs $cls")
-    for (decl <- cls.info.decls) {
+
+    def checkDecl(decl: Symbol): Unit = {
       for (other <- seen(decl.name)) {
         typr.println(i"conflict? $decl $other")
         if (decl.signature matches other.signature) {
@@ -129,6 +130,12 @@ trait Checking {
       }
       seen(decl.name) = decl :: seen(decl.name)
     }
+
+    cls.info.decls.foreach(checkDecl)
+    cls.info match {
+      case ClassInfo(_, _, _, _, selfSym: Symbol) => checkDecl(selfSym)
+      case _ =>
+    }
   }
 
   def checkInstantiatable(cls: ClassSymbol, pos: Position): Unit = {
diff --git a/src/dotty/tools/dotc/typer/Namer.scala b/src/dotty/tools/dotc/typer/Namer.scala
index 2425bea50..cce2f7318 100644
--- a/src/dotty/tools/dotc/typer/Namer.scala
+++ b/src/dotty/tools/dotc/typer/Namer.scala
@@ -209,7 +209,7 @@ class Namer { typer: Typer =>
           ctx.error(s"${preExisting.showLocated} is compiled twice, runid = ${ctx.runId}", tree.pos)
         }
       else if ((!ctx.owner.isClass || name.isTypeName) && preExisting.exists) {
-        ctx.error(d"$name is already defined as $preExisting")
+        ctx.error(i"$name is already defined as $preExisting", tree.pos)
       }
     }
 
diff --git a/tests/neg/typers.scala b/tests/neg/typers.scala
index d25a8911e..2f1cf40c4 100644
--- a/tests/neg/typers.scala
+++ b/tests/neg/typers.scala
@@ -1,40 +1,56 @@
 object typers {
-  
+
+  class A(x: Int) {
+    val x: String = "a"  // error: double def
+
+    { val y: String = ""
+      val y: Int = 0     // error: double def
+      y
+    }
+  }
+
+  class B { self =>      // error: double def
+    def self: Int = 0
+    def self(x: Int): Int = x
+  }
+
   class C {
     val x: Int
-    val x: String
+    val x: String        // error: double def
     val y: Int
-    def y: String
+    def y: String        // error: double def
     val z: Int
-    def z(): String
-    
-    def f(x: Any) = ()
+    def z(): String      // error: double def
+
+    def f(x: Any) = ()   // error: double def
     def f(x: AnyRef): AnyRef
-    
+
     def g(x: Object): Unit
-    def g[T](x: T): T = x
+    def g[T](x: T): T = x  // error: double def
   }
-  
-  
+
+
+
+
   object returns {
-    
-    def foo(x: Int) = {
+
+    def foo(x: Int) = {   // error: has return; needs result type
       return 3
     }
-    
-    return 4
+
+    return 4            // error: return outside method definition
   }
-  
+
   object cyclic {
-    def factorial(acc: Int, n: Int) = 
+    def factorial(acc: Int, n: Int) =
       if (n == 0) acc
-      else factorial(acc * n, n - 1)
-      
-    def foo(x: Int) = x
+      else factorial(acc * n, n - 1)    // error: cyclic reference
+
+    def foo(x: Int) = x                 // error: cyclic reference
     def foo() = foo(1)
-      
+
   }
-  
+
   object tries {
 
     val x = try {
@@ -46,6 +62,6 @@ object typers {
   }
 
   class Refinements {
-    val y: C { val x: T; type T }
+    val y: C { val x: T; type T }  // error: illegal forward reference in refinement
   }
-}
-\ No newline at end of file
+}
diff --git a/tests/pos/typers.scala b/tests/pos/typers.scala
index cb3bbc590..4f012e7bf 100644
--- a/tests/pos/typers.scala
+++ b/tests/pos/typers.scala
@@ -1,61 +1,61 @@
-package test 
+package test
 
 import annotation.{tailrec, switch}
 import collection.mutable._
 
 object typers {
-  
+
   val names = List("a", "b", "c")
   val ints = List(1, 2, 3)
-  
+
   object Inference {
 
     for ((name, n) <- (names, ints).zipped)
       println(name.length + n)
-      
+
     def double(x: Char): String = s"$x$x"
-    
+
     "abc" flatMap double
-  
+
   }
   object Eta {
-    
+
     def fun(x: Int): Int = x + 1
     val foo = fun(_)
   }
-  
+
   case class DefaultParams(init: String => String = identity)
   object DefaultParams {
     def foo(x: String => String = identity) = x("abc")
-    
+
     foo()
   }
-  
+
   class List[+T] {
     def :: (x: T) = new :: (x, this)
-    
+
     def len: Int = this match {
       case x :: xs1 => 1 + xs1.len
       case Nil => 0
     }
   }
-  
+
   object Nil extends List[Nothing]
-  
+
   case class :: [+T] (hd: T, tl: List[T]) extends List[T]
-  
+
   def len[U](xs: List[U]): Int = xs match {
     case x :: xs1 => 1 + len(xs1)
     case Nil => 0
   }
-  
+
   object returns {
-    
+
     def foo(x: Int): Int = {
       return 3
     }
   }
-  
+
   object tries {
 
     val x = try {
@@ -70,69 +70,71 @@ object typers {
     val y = try 2 catch Predef.identity
 
     val z = try 3 finally "abc"
-    
+
     println("abc".toString)
 
   }
 
   class C {
-    
+
     @tailrec def factorial(acc: Int, n: Int): Int = (n: @switch) match {
       case 0 => acc
       case _ => factorial(acc * n, n - 1)
     }
-      
+
     println(factorial(1, 10))
-    
-    
+
+
   }
-  
+
   class Refinements {
     val y: C { type T; val key: T; def process(x: T): Int }
   }
-  
+
   object Accessibility {
-    
+
     class A {
       val x: String = "abc"
     }
-    
+
     class B extends A {
       private def x: Int = 1
     }
-    
+
     val b: B = new B
     val y = b.x
     val z: String = y
-    
+
   }
-  
+
   object Self {
-    
-    class A(self: Int) { self =>
-      
+
+    class A(self1: Int) { self =>
+
+      def self1(x: Int) = x
+
       class B {
         val b = self
         val c: A = b
       }
-      
+
       val a = self
       val c: A = a
     }
-    
-    
+
+
   }
-  
+
   object Arrays {
-    
+
     val arr = List("a", "b", "c").toArray
     val i = 2
     arr(i).charAt(0)
-    
+
     val x = new ArrayBuffer[String] // testing overloaded polymorphic constructors
 
     val entries = Array("abc", "def")
-    
+
     for ((x, i) <- entries.zipWithIndex)
       println(x)
   }
@@ -145,6 +147,6 @@ object typers {
     }
     val yy: String = y
   }
-  
 
-}
-\ No newline at end of file
+
+}