1 files changed, 23 insertions, 0 deletions
diff --git a/test/files/neg/t6902.scala b/test/files/neg/t6902.scala
new file mode 100644
index 0000000000..ce5ff8b6fb
--- /dev/null
+++ b/test/files/neg/t6902.scala
@@ -0,0 +1,23 @@
+object Test {
+  Some(Some(1)) collect {
+    case Some(a) => 2
+    case Some(b) => 3 // no warning was emitted
+  }
+
+  (Some(1): @ unchecked) match {
+    case Some(a) => 2
+    case Some(b) => 3 // no warning was emitted
+  }
+
+  // A variation of SI-6011, which eluded the fix
+  // in 2.10.0.
+  //
+  // duplicate keys in SWITCH, can't pick arbitrarily one of them to evict, see SI-6011.
+  // at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:50)
+  // at scala.tools.nsc.Global.abort(Global.scala:249)
+  // at scala.tools.nsc.backend.jvm.GenASM$JPlainBuilder$jcode$.emitSWITCH(GenASM.scala:1850)
+  ((1: Byte): @unchecked @annotation.switch) match {
+    case 1 => 2
+    case 1 => 3 // crash
+  }
+}