Merge pull request #6857 from dotty-staging/fix-#6822

Fix #6822: Fix self type handling for opaque types in classes

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -443,7 +443,8 @@ object SymDenotations {
             val enclClassInfo = owner.asClass.classInfo
             enclClassInfo.selfInfo match {
               case self: Type =>
-                owner.info = enclClassInfo.derivedClassInfo(selfInfo = refineSelfType(self))
+                owner.info = enclClassInfo.derivedClassInfo(
+                  selfInfo = refineSelfType(self.orElse(defn.AnyType)))
               case self: Symbol =>
                 self.info = refineSelfType(self.info)
             }
@@ -1177,7 +1178,7 @@ object SymDenotations {
         case _ =>
           NoType
       }
-      recur(owner.asClass.classInfo.selfType)
+      recur(owner.asClass.givenSelfType)
     }
 
     /** The non-private symbol whose name and type matches the type of this symbol

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -511,7 +511,7 @@ class TreePickler(pickler: TastyPickler) {
             pickleParams(params)
             tree.parents.foreach(pickleTree)
             val cinfo @ ClassInfo(_, _, _, _, selfInfo) = tree.symbol.owner.info
-            if ((selfInfo ne NoType) || !tree.self.isEmpty) {
+            if (!tree.self.isEmpty) {
               writeByte(SELFDEF)
               pickleName(tree.self.name)
 

tests/pos/i6822.scala

@@ -0,0 +1,3 @@
+class C {
+  opaque type T = Int
+}