1 files changed, 38 insertions, 0 deletions
diff --git a/test/files/pos/t1957.scala b/test/files/pos/t1957.scala
new file mode 100644
index 0000000000..f80cf730ed
--- /dev/null
+++ b/test/files/pos/t1957.scala
@@ -0,0 +1,38 @@
+object Test {
+    abstract class Settings {}
+
+    abstract class Grist
+    { self =>
+        type settingsType <: Settings
+        type moduleType <: Module {type settingsType = self.settingsType}
+        val module: moduleType
+    }
+
+    abstract class Tool
+    { self =>
+        type settingsType <: Settings
+        type moduleType = Module { type settingsType = self.settingsType }
+        type gristType = Grist { type moduleType <: self.moduleType; type settingsType <: self.settingsType }
+
+        def inputGrist: List[gristType]
+    }
+
+    abstract class Module
+    { self =>
+        type settingsType <: Settings
+        final type commonModuleType = Module {type settingsType = self.settingsType}
+        type selfType >: self.type <: commonModuleType
+
+        // BTW: if we use the commented out type declarations, the code compiles successfully
+        // type gristType = Grist {type settingsType <: self.settingsType; type moduleType <: commonModuleType }
+
+        val tools: List[Tool {type settingsType = self.settingsType}]
+
+        protected def f: List[commonModuleType] =
+        {
+            val inputGrists = tools.flatMap(_.inputGrist) // val inputGrists: List[gristType] =
+            inputGrists.map(_.module)
+        }
+
+    }
+}