clear all flags when resetting a symbol

this change is a bit scary because it changes code that's not been
changed in 11 years
https://github.com/scala/scala/commit/7fa7c93#diff-d5789e5ae5061197d782d08324b260dbL214

1 files changed, 11 insertions, 0 deletions

diff --git a/test/junit/scala/tools/nsc/backend/jvm/DirectCompileTest.scala b/test/junit/scala/tools/nsc/backend/jvm/DirectCompileTest.scala
index f835e9b140..36bdb759a6 100644
--- a/test/junit/scala/tools/nsc/backend/jvm/DirectCompileTest.scala
+++ b/test/junit/scala/tools/nsc/backend/jvm/DirectCompileTest.scala
@@ -88,4 +88,15 @@ class DirectCompileTest extends BytecodeTesting {
   def compileErroneous(): Unit = {
     compileToBytes("class C { def f: String = 1 }", allowMessage = _.msg contains "type mismatch")
   }
+
+  @Test
+  def residentRedefineFinalFlag(): Unit = {
+    val compiler = newCompiler()
+    val a = "final class C { def c1 = 0 }"
+    // for re-defined class symbols (C), the compiler did not clear the `final` flag.
+    // so compiling `D` would give an error `illegal inheritance from final class C`.
+    val b = "class C; class D extends C"
+    compiler.compileToBytes(a)
+    compiler.compileToBytes(b)
+  }
 }