7 files changed, 78 insertions, 9 deletions
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 636f1e2f01..7e6de14295 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -191,7 +191,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
 
         } else None
       }
-      
+
       // Begin Reflection Helpers
 
       // Replaces a repeated parameter type at the end of the parameter list
@@ -354,7 +354,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       val selection = select(alts, defaultFilteringOps)
 
       val knownApplicable = applicable(selection)
-      
+
       if (knownApplicable.size == 1) knownApplicable.head
       else NoSymbol
     }
@@ -1016,6 +1016,14 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
 
     def isTopLevelModule = hasFlag(MODULE) && owner.isPackageClass
 
+    /** A helper function for isEffectivelyFinal. */
+    private def isNotOverridden = (
+      owner.isClass && (
+           owner.isEffectivelyFinal
+        || owner.isSealed && owner.children.forall(c => c.isEffectivelyFinal && (overridingSymbol(c) == NoSymbol))
+      )
+    )
+
     /** Is this symbol effectively final? I.e, it cannot be overridden */
     final def isEffectivelyFinal: Boolean = (
          (this hasFlag FINAL | PACKAGE)
@@ -1023,8 +1031,8 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       || isTerm && (
              isPrivate
           || isLocal
-          || owner.isClass && owner.isEffectivelyFinal
-      )
+          || isNotOverridden
+         )
     )
 
     /** Is this symbol locally defined? I.e. not accessed from outside `this` instance */
diff --git a/test/files/neg/sealed-final-neg.check b/test/files/neg/sealed-final-neg.check
new file mode 100644
index 0000000000..500d23f49a
--- /dev/null
+++ b/test/files/neg/sealed-final-neg.check
@@ -0,0 +1,4 @@
+sealed-final-neg.scala:41: error: expected class or object definition
+"Due to SI-6142 this emits no warnings, so we'll just break it until that's fixed."
+^
+one error found
diff --git a/test/files/neg/sealed-final-neg.flags b/test/files/neg/sealed-final-neg.flags
new file mode 100644
index 0000000000..cfabf7a5b4
--- /dev/null
+++ b/test/files/neg/sealed-final-neg.flags
@@ -0,0 +1 @@
+-Xfatal-warnings -Yinline-warnings -optimise
+\ No newline at end of file
diff --git a/test/files/neg/sealed-final-neg.scala b/test/files/neg/sealed-final-neg.scala
new file mode 100644
index 0000000000..bc25330e13
--- /dev/null
+++ b/test/files/neg/sealed-final-neg.scala
@@ -0,0 +1,41 @@
+package neg1 {
+  sealed abstract class Foo {
+    @inline def bar(x: Int) = x + 1
+  }
+  object Foo {
+    def mkFoo(): Foo = new Baz2
+  }
+
+  object Baz1 extends Foo
+  final class Baz2 extends Foo
+  final class Baz3 extends Foo {
+    override def bar(x: Int) = x - 1
+  }
+
+  object Test {
+    // bar can't be inlined - it is overridden in Baz3
+    def f = Foo.mkFoo() bar 10
+  }
+}
+
+package neg2 {
+  sealed abstract class Foo {
+    @inline def bar(x: Int) = x + 1
+  }
+  object Foo {
+    def mkFoo(): Foo = new Baz2
+  }
+
+  object Baz1 extends Foo
+  final class Baz2 extends Foo
+  class Baz3 extends Foo {
+    override def bar(x: Int) = x - 1
+  }
+
+  object Test {
+    // bar can't be inlined - Baz3 is not final
+    def f = Foo.mkFoo() bar 10
+  }
+}
+
+"Due to SI-6142 this emits no warnings, so we'll just break it until that's fixed."
diff --git a/test/files/pos/sealed-final.flags b/test/files/pos/sealed-final.flags
new file mode 100644
index 0000000000..cfabf7a5b4
--- /dev/null
+++ b/test/files/pos/sealed-final.flags
@@ -0,0 +1 @@
+-Xfatal-warnings -Yinline-warnings -optimise
+\ No newline at end of file
diff --git a/test/files/pos/sealed-final.scala b/test/files/pos/sealed-final.scala
new file mode 100644
index 0000000000..bdedb5c1f6
--- /dev/null
+++ b/test/files/pos/sealed-final.scala
@@ -0,0 +1,14 @@
+sealed abstract class Foo {
+  @inline def bar(x: Int) = x + 1
+}
+object Foo {
+  def mkFoo(): Foo = new Baz2
+}
+
+object Baz1 extends Foo
+final class Baz2 extends Foo
+
+object Test {
+  // bar should be inlined now
+  def f = Foo.mkFoo() bar 10
+}
diff --git a/test/files/run/t2886.check b/test/files/run/t2886.check
index 8d97a82799..b093815562 100644
--- a/test/files/run/t2886.check
+++ b/test/files/run/t2886.check
@@ -1,5 +1,5 @@
-((x: String) => {
-  val x$1 = x;
-  val x$2 = x;
-  Test.this.test(x$2, x$1)
-})
+((x: String) => {
+  <hidden> val x$1 = x;
+  <hidden> val x$2 = x;
+  Test.this.test(x$2, x$1)
+})