6 files changed, 53 insertions, 4 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index c527bb981b..29af968d2a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -335,6 +335,7 @@ trait Namers requires Analyzer {
         if (settings.debug.value) log("defining " + sym);
         val tp = typeSig(tree)
         sym.setInfo(tp)
+        if (sym.isType) typer.checkNonCyclic(sym)
         if (settings.debug.value) log("defined " + sym);
         validate(sym)
       }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 1b1b1823a3..ff4c5f75d4 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -845,6 +845,8 @@ trait Typers requires Analyzer {
         val value = vdef.symbol
         val getter = if (mods hasFlag DEFERRED) value else value.getter(value.owner)
         assert(getter != NoSymbol, stat)
+        if (getter hasFlag OVERLOADED)
+          error(getter.pos, ""+getter+" is defined twice")
         val getterDef: DefDef = {
           val result = DefDef(getter, vparamss =>
               if (mods hasFlag DEFERRED) EmptyTree
@@ -855,11 +857,14 @@ trait Typers requires Analyzer {
           result
         }
         def setterDef: DefDef = {
+          val setr = getter.setter(value.owner)
           val result = atPos(vdef.pos)(
-            DefDef(getter.setter(value.owner), vparamss =>
-              if (mods hasFlag DEFERRED) EmptyTree
-              else typed(Assign(Select(This(value.owner), value),
-                                Ident(vparamss.head.head)))))
+            DefDef(setr, vparamss =>
+              if ((mods hasFlag DEFERRED) || (setr hasFlag OVERLOADED))
+                EmptyTree
+              else
+                typed(Assign(Select(This(value.owner), value),
+                             Ident(vparamss.head.head)))))
           result.mods setAttr vdef.mods.attributes
           result
         }
diff --git a/test/files/neg/bug798.check b/test/files/neg/bug798.check
new file mode 100644
index 0000000000..6fd80bcba5
--- /dev/null
+++ b/test/files/neg/bug798.check
@@ -0,0 +1,4 @@
+bug798.scala:5 error: cyclic aliasing or subtyping involving type Bracks
+  type Bracks <: Bracks
+       ^
+one error found
diff --git a/test/files/neg/bug798.scala b/test/files/neg/bug798.scala
new file mode 100644
index 0000000000..9d95ae2ddb
--- /dev/null
+++ b/test/files/neg/bug798.scala
@@ -0,0 +1,9 @@
+package test;
+trait Test {
+  def f(list : Any) = null;
+  class C[T]
+  type Bracks <: Bracks
+  val bracks : Bracks;
+  val singletons = f(bracks);
+
+}
diff --git a/test/files/neg/bug800.check b/test/files/neg/bug800.check
new file mode 100644
index 0000000000..eae84677c9
--- /dev/null
+++ b/test/files/neg/bug800.check
@@ -0,0 +1,13 @@
+bug800.scala:4 error: qualification is already defined as value qualification
+  val qualification = false;
+      ^
+bug800.scala:8 error: method qualification is defined twice
+  val qualification = false;
+      ^
+bug800.scala:12 error: value qualification is defined twice
+  var qualification = false;
+  ^
+bug800.scala:16 error: method qualification is defined twice
+  var qualification = false;
+  ^
+four errors found
diff --git a/test/files/neg/bug800.scala b/test/files/neg/bug800.scala
new file mode 100644
index 0000000000..388574d42d
--- /dev/null
+++ b/test/files/neg/bug800.scala
@@ -0,0 +1,17 @@
+package test;
+trait Test1 {
+  val qualification : String;
+  val qualification = false;
+}
+trait Test2 {
+  var qualification : String;
+  val qualification = false;
+}
+trait Test3 {
+  val qualification : String;
+  var qualification = false;
+}
+trait Test4 {
+  var qualification : String;
+  var qualification = false;
+}