Fix crash error

Author: noti0na1

compiler/src/dotty/tools/dotc/cc/CaptureRef.scala

@@ -146,9 +146,8 @@ trait CaptureRef extends TypeProxy, ValueType:
           y.info match
             case TypeBounds(_, hi: CaptureRef) => this.subsumes(hi)
             case _ => y.captureSetOfInfo.elems.forall(this.subsumes)
-        case AnnotatedType(parent, ann)
-        if ann.symbol.isRetains && parent.derivesFrom(defn.Caps_CapSet) =>
-          ann.tree.toCaptureSet.elems.forall(this.subsumes)
+        case CapturingType(parent, refs) if parent.derivesFrom(defn.Caps_CapSet) =>
+          refs.elems.forall(this.subsumes)
         case _ => false
     || this.match
         case ReachCapability(x1) => x1.subsumes(y.stripReach)
@@ -161,9 +160,8 @@ trait CaptureRef extends TypeProxy, ValueType:
               lo.subsumes(y)
             case _ =>
               x.captureSetOfInfo.elems.exists(_.subsumes(y))
-        case AnnotatedType(parent, ann)
-        if ann.symbol.isRetains && parent.derivesFrom(defn.Caps_CapSet) =>
-          ann.tree.toCaptureSet.elems.exists(_.subsumes(y))
+        case CapturingType(parent, refs) if parent.derivesFrom(defn.Caps_CapSet) =>
+          refs.elems.exists(_.subsumes(y))
         case _ => false
   end subsumes
 

tests/neg-custom-args/captures/capset-members.scala

@@ -22,6 +22,9 @@ class Concrete4(a: AnyRef^) extends Abstract[CapSet^{a}]:
   def boom(): AnyRef^{a} = a // error
 
 class Concrete5(a: AnyRef^, b: AnyRef^) extends Abstract[CapSet^{a}]:
-  // TODO: Crash with the type member
-  // type C = CapSet^{a}
+  type C = CapSet^{a}
   def boom(): AnyRef^{b} = b // error
+
+class Concrete6(a: AnyRef^, b: AnyRef^) extends Abstract[CapSet^{a}]:
+  def boom(): AnyRef^{b} = b // error
+  

tests/neg-custom-args/captures/i21868b.scala

@@ -30,9 +30,15 @@ class Concrete4(io: IO^) extends Abstract2(io):
   def f(file: File) = ()
 
 // TODO: Should be an error
-// class Concrete5(io1: IO^, io2: IO^) extends Abstract2(io1):
-//   type C = CapSet^{io2}
-//   def f(file: File^{io2}) = ()
+class Concrete5(io1: IO^, io2: IO^) extends Abstract2(io1):
+  // Similar to Concrete8, this type member should have overriding error.
+  // Parent class is Abstract2 { val io = Concrete5.this.io1 }
+  // Abstract2.this.C >: CapSet <: CapSet^{Concrete5.this.io1}
+  // Concrete5.this.C = CapSet^{Concrete5.this.io2}
+  // CapSet^{Concrete5.this.io2} !<:< CapSet^{Concrete5.this.io1}
+  // Hence, Concrete5.this.C !<:< Abstract2.this.C
+  type C = CapSet^{io2}
+  def f(file: File^{io2}) = ()
 
 trait Abstract3[X^]:
   type C >: CapSet <: X