diff --git a/test/files/neg/bug500.check b/test/files/neg/bug500.check
new file mode 100644
index 000000000..245945fbc
--- /dev/null
+++ b/test/files/neg/bug500.check
@@ -0,0 +1,4 @@
+bug500.scala:3 error: lower bound X does not conform to upper bound Y
+    type T >: X <: Y;
+         ^
+one error found
diff --git a/test/files/neg/bug500.scala b/test/files/neg/bug500.scala
new file mode 100644
index 000000000..d572cd8b8
--- /dev/null
+++ b/test/files/neg/bug500.scala
@@ -0,0 +1,22 @@
+object Magic {
+  abstract class O[X,Y] {
+    type T >: X <: Y;
+    class I { def magic(v: T): T = v; }
+  }
+  def magic[X,Y](v: X): Y = {
+    val o: O[X,Y] = null;
+    val i: o.I = new o.I();
+    i.magic(v);
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    try {
+      val i: Int = Magic.magic("42");
+      System.out.println(i);
+    } catch {
+      case ex: Throwable => ex.printStackTrace()
+    }
+  }
+}
diff --git a/test/files/neg/bug501.check b/test/files/neg/bug501.check
new file mode 100644
index 000000000..7b00a3903
--- /dev/null
+++ b/test/files/neg/bug501.check
@@ -0,0 +1,4 @@
+bug501.scala:3 error: lower bound X does not conform to upper bound Y
+    abstract class I { type T >: X <: Y; }
+                            ^
+one error found
diff --git a/test/files/neg/bug501.scala b/test/files/neg/bug501.scala
new file mode 100644
index 000000000..454344974
--- /dev/null
+++ b/test/files/neg/bug501.scala
@@ -0,0 +1,18 @@
+object Magic {
+  class O[X,Y] {
+    abstract class I { type T >: X <: Y; }
+    val i: I = null;
+    def magic(v: i.T): i.T = v;
+  }
+  def magic[X,Y](v: X): Y = {
+    val o: O[X,Y] = new O();
+    o.magic(v);
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val i: Int = Magic.magic("42");
+    System.out.println(i);
+  }
+}
diff --git a/test/files/neg/bug520.check b/test/files/neg/bug520.check
new file mode 100644
index 000000000..4fb56d90f
--- /dev/null
+++ b/test/files/neg/bug520.check
@@ -0,0 +1,4 @@
+bug520.scala:8 error: overloaded method verifyKeyword needs result type
+      verifyKeyword("", source, pos);
+      ^
+one error found
diff --git a/test/files/neg/bug520.scala b/test/files/neg/bug520.scala
new file mode 100644
index 000000000..949a50951
--- /dev/null
+++ b/test/files/neg/bug520.scala
@@ -0,0 +1,9 @@
+object test {
+
+   def verifyKeyword(keyword : String, source : java.io.File, pos : Int) = {
+      assert(keyword != null);
+    }
+
+    def verifyKeyword(source : java.io.File, pos : Int) = 
+      verifyKeyword("", source, pos);
+}
diff --git a/test/files/neg/bug521.check b/test/files/neg/bug521.check
new file mode 100644
index 000000000..818f80052
--- /dev/null
+++ b/test/files/neg/bug521.check
@@ -0,0 +1,15 @@
+bug521.scala:12 error: class PlainFile needs to be abstract, since method path in class AbstractFile of type => java.lang.String is not defined
+class PlainFile(val file : File) extends AbstractFile {}
+^
+bug521.scala:21 error: error overriding value file in class PlainFile of type => java.io.File;
+ value file needs `override' modifier
+final class ZipArchive(val file : File, archive : ZipFile) extends PlainFile(file) {
+                       ^
+bug521.scala:21 error: class ZipArchive needs to be abstract, since method path in class AbstractFile of type => java.lang.String is not defined
+final class ZipArchive(val file : File, archive : ZipFile) extends PlainFile(file) {
+      ^
+bug521.scala:23 error: error overriding value path in class VirtualFile of type => java.lang.String;
+ method path needs to be an immutable value
+    override def path = "";
+             ^
+four errors found
diff --git a/test/files/neg/bug521.scala b/test/files/neg/bug521.scala
new file mode 100755
index 000000000..065f65557
--- /dev/null
+++ b/test/files/neg/bug521.scala
@@ -0,0 +1,25 @@
+
+// AbstractFile.scala
+package test;
+import java.io._;
+abstract class AbstractFile {
+  def path : String;
+}
+
+// PlainFile.scala
+//package scala.tools.nsc.io;
+//import java.io._;
+class PlainFile(val file : File) extends AbstractFile {}
+// VirtualFile.scala
+//package scala.tools.nsc.io;
+class VirtualFile(val name : String, val path : String) extends AbstractFile {
+}
+// ZipArchive.scala
+//package scala.tools.nsc.io;
+//import java.io._;
+import java.util.zip._;
+final class ZipArchive(val file : File, archive : ZipFile) extends PlainFile(file) {
+  class Entry(name : String, path : String) extends VirtualFile(name, path) {
+    override def path = "";
+  }
+}
diff --git a/test/files/neg/mixins.check b/test/files/neg/mixins.check
new file mode 100644
index 000000000..805f9c424
--- /dev/null
+++ b/test/files/neg/mixins.check
@@ -0,0 +1,6 @@
+mixins.scala:9 error: illegal inheritance; superclass C
+ is not a subclass of the superclass B
+ of the mixin class M
+class D extends C with M
+                       ^
+one error found
diff --git a/test/files/neg/mixins.scala b/test/files/neg/mixins.scala
new file mode 100644
index 000000000..dd0ec2332
--- /dev/null
+++ b/test/files/neg/mixins.scala
@@ -0,0 +1,9 @@
+class A;
+
+class B extends A
+
+class C extends A
+
+mixin class M extends B
+
+class D extends C with M
diff --git a/test/files/run/bridges.scala b/test/files/run/bridges.scala
index bf3781fde..65ba2f13c 100644
--- a/test/files/run/bridges.scala
+++ b/test/files/run/bridges.scala
@@ -39,21 +39,21 @@ import Help.bar;
 import Help.mix;
 import Help.sub;
 
-abstract class Foo___    { type  I<:AnyRef; def f: I              ; f; }
-abstract class Foo__f    { type  I<:AnyRef; def f: I = {foo; null}; f; }
+abstract class Foo___    { type  I>:AllRef<:AnyRef; def f: I              ; f; }
+abstract class Foo__f    { type  I>:AllRef<:AnyRef; def f: I = {foo; null}; f; }
 abstract class Foo_I_    { class I        ; def f: I              ; f; }
 abstract class Foo_If    { class I        ; def f: I = {foo; null}; f; }
-abstract class FooX__[X] { type  I<:AnyRef; def f: I              ; f; }
-abstract class FooX_f[X] { type  I<:AnyRef; def f: I = {foo; null}; f; }
+abstract class FooX__[X] { type  I>:AllRef<:AnyRef; def f: I              ; f; }
+abstract class FooX_f[X] { type  I>:AllRef<:AnyRef; def f: I = {foo; null}; f; }
 abstract class FooXI_[X] { class I        ; def f: I              ; f; }
 abstract class FooXIf[X] { class I        ; def f: I = {foo; null}; f; }
 
-trait Bar___    { type  I<:AnyRef; def f: I              ; f; }
-trait Bar__f    { type  I<:AnyRef; def f: I = {bar; null}; f; }
+trait Bar___    { type  I>:AllRef<:AnyRef; def f: I              ; f; }
+trait Bar__f    { type  I>:AllRef<:AnyRef; def f: I = {bar; null}; f; }
 trait Bar_I_    { class I        ; def f: I              ; f; }
 trait Bar_If    { class I        ; def f: I = {bar; null}; f; }
-trait BarY__[Y] { type  I<:AnyRef; def f: I              ; f; }
-trait BarY_f[Y] { type  I<:AnyRef; def f: I = {bar; null}; f; }
+trait BarY__[Y] { type  I>:AllRef<:AnyRef; def f: I              ; f; }
+trait BarY_f[Y] { type  I>:AllRef<:AnyRef; def f: I = {bar; null}; f; }
 trait BarYI_[Y] { class I        ; def f: I              ; f; }
 trait BarYIf[Y] { class I        ; def f: I = {bar; null}; f; }
 
diff --git a/test/files/run/bugs.scala b/test/files/run/bugs.scala
index 4cb8dbeb3..2c940834e 100644
--- a/test/files/run/bugs.scala
+++ b/test/files/run/bugs.scala
@@ -335,7 +335,7 @@ object Bug257Test {
 // version - A
 
 abstract class Bug266AFoo {
-  type T <: AnyRef;
+  type T >: AllRef <: AnyRef;
   abstract class I0 { def f(x: T): Unit; f(null); }
 }