Merge pull request #3073 from retronym/ticket/7928

 Favour module accessors symbols in rebind

2 files changed, 21 insertions, 1 deletions

diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index 204a2e7088..59d1e13142 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -3385,7 +3385,11 @@ trait Types
   /** Rebind symbol `sym` to an overriding member in type `pre`. */
   private def rebind(pre: Type, sym: Symbol): Symbol = {
     if (!sym.isOverridableMember || sym.owner == pre.typeSymbol) sym
-    else pre.nonPrivateMember(sym.name).suchThat(sym => sym.isType || (sym.isStable && !sym.hasVolatileType)) orElse sym
+    else pre.nonPrivateMember(sym.name).suchThat(sym =>
+      // SI-7928 `isModuleNotMethod` is here to avoid crashing with overloaded module accessor and module symbols
+      //         after refchecks eliminates a ModuleDef that implements and interface.
+      sym.isType || (!sym.isModuleNotMethod && sym.isStable && !sym.hasVolatileType)
+    ) orElse sym
   }
 
   /** Convert a `super` prefix to a this-type if `sym` is abstract or final. */
diff --git a/test/files/pos/t7928.scala b/test/files/pos/t7928.scala
new file mode 100644
index 0000000000..d9e29935b3
--- /dev/null
+++ b/test/files/pos/t7928.scala
@@ -0,0 +1,16 @@
+trait OuterTrait {
+  trait InnerTrait {
+    type Element
+    type Collection <: Iterable[Inner.Element]
+  }
+
+  val Inner: InnerTrait
+
+}
+
+object OuterObject extends OuterTrait {
+  object Inner extends InnerTrait {
+    type Element = String
+    override type Collection = Seq[Inner.Element]
+  }
+}