Closes #3816. Review by moors.

3 files changed, 52 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 58f0532e39..e0e8efb007 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -3623,10 +3623,11 @@ trait Typers { self: Analyzer =>
         // are made to disappear here. In addition,
         // if we are in a constructor of a pattern, we ignore all definitions
         // which are methods (note: if we don't do that
-        // case x :: xs in class List would return the :: method).
+        // case x :: xs in class List would return the :: method)
+        // unless they are stable or are accessors (the latter exception is for better error messages).
         def qualifies(sym: Symbol): Boolean = {
           reallyExists(sym) &&
-          ((mode & PATTERNmode | FUNmode) != (PATTERNmode | FUNmode) || !sym.isSourceMethod)
+          ((mode & PATTERNmode | FUNmode) != (PATTERNmode | FUNmode) || !sym.isSourceMethod || sym.hasFlag(ACCESSOR))
         }
 
         if (defSym == NoSymbol) {
diff --git a/test/files/neg/t3816.check b/test/files/neg/t3816.check
new file mode 100644
index 0000000000..3658e76b64
--- /dev/null
+++ b/test/files/neg/t3816.check
@@ -0,0 +1,7 @@
+t3816.scala:30: error: stable identifier required, but syncID found.
+      case Some( `syncID` ) =>
+                 ^
+t3816.scala:38: error: stable identifier required, but Test.this.foo found.
+      case Some( `foo` ) =>
+                 ^
+two errors found
diff --git a/test/files/neg/t3816.scala b/test/files/neg/t3816.scala
new file mode 100644
index 0000000000..31b0825f1d
--- /dev/null
+++ b/test/files/neg/t3816.scala
@@ -0,0 +1,42 @@
+class B {
+    def ::(a: List[Int]) {
+        a match {
+            case x::xs =>
+            case _ =>
+        }
+    }
+}
+
+object Test {
+  def testSuccess1( x: Any ) = {
+    val stable = 2
+    x match {
+      case Some( `stable` ) =>
+      case _ =>
+    }
+  }
+
+  val bar = 3
+  def testSuccess2( x: Any ) = {
+    x match {
+      case Some( `bar` ) =>
+      case _ =>
+    }
+  }
+
+  def testFail1( x: Any ) = {
+    var syncID = 0
+    x match {
+      case Some( `syncID` ) =>
+      case _ =>
+    }
+  }
+
+  var foo = 0
+  def testFail2( x: Any ) = {
+    x match {
+      case Some( `foo` ) =>
+      case _ =>
+    }
+  }
+}