Fix for regression in overriding with defaults.

I should know better than to behave as if usable inferences can be drawn
from a comment like "SYNTHETIC because of DEVIRTUALIZE". Maybe it was
even true when it was written, but no more. Closes SI-5178, no review.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index c3c353385c..1c4355b3bd 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -364,7 +364,8 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R
             overrideError("cannot be used here - classes can only override abstract types");
           } else if (other.isFinal) { // (1.2)
             overrideError("cannot override final member");
-          } else if (!other.isDeferred && !member.isAnyOverride) {
+            // synthetic exclusion needed for (at least) default getters.
+          } else if (!other.isDeferred && !member.isAnyOverride && !member.isSynthetic) {
             overrideError("needs `override' modifier");
           } else if (other.isAbstractOverride && other.isIncompleteIn(clazz) && !member.isAbstractOverride) {
             overrideError("needs `abstract override' modifiers")