Transcendent rewrite of isSameType.

A highly satisfying rewrite of isSameType. It's faster, clearer,
shorter, better commented, and closer to correct. I am especially
pleased that t5580b stopped compiling, given that nobody seemed to
have much idea why it compiled in the first place.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/files/neg/t5580b.scala b/test/files/neg/t5580b.scala
new file mode 100644
index 0000000000..2161da4584
--- /dev/null
+++ b/test/files/neg/t5580b.scala
@@ -0,0 +1,13 @@
+import scala.collection.mutable.WeakHashMap
+import scala.collection.JavaConversions._
+
+class bar { }
+
+class foo {
+  val map = WeakHashMap[AnyRef, collection.mutable.Map[bar, collection.mutable.Set[bar]]]()
+
+  def test={
+    val tmp:bar=null
+    if (map.get(tmp).isEmpty) map.put(tmp,collection.mutable.Set())
+  }
+}