Change owner of computed capture set for constructor applications

Author: odersky

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

@@ -274,6 +274,11 @@ sealed abstract class CaptureSet extends Showable:
       else Const(elems.filter(p))
     else Filtered(asVar, p)
 
+  /** This set with a new owner and therefore also a new levelLimit */
+  def changeOwner(newOwner: Symbol)(using Context): CaptureSet =
+    if this.isConst then this
+    else ChangedOwner(asVar, newOwner)
+
   /** Capture set obtained by applying `tm` to all elements of the current capture set
    *  and joining the results. If the current capture set is a variable, the same
    *  transformation is applied to all future additions of new elements.
@@ -752,6 +757,10 @@ object CaptureSet:
     override def toString = s"BiMapped$id($source, elems = $elems)"
   end BiMapped
 
+  /** Same as `source` but with a new directOwner */
+  class ChangedOwner private[CaptureSet](val source: Var, newOwner: Symbol)(using @constructorOnly ctx: Context)
+  extends DerivedVar(newOwner, source.elems)
+
   /** A variable with elements given at any time as { x <- source.elems | p(x) } */
   class Filtered private[CaptureSet]
     (val source: Var, p: Context ?=> CaptureRef => Boolean)(using @constructorOnly ctx: Context)

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

@@ -509,7 +509,7 @@ class CheckCaptures extends Recheck, SymTransformer:
             augmentConstructorType(parent, initCs ++ refs)
           case _ =>
             val (refined, cs) = addParamArgRefinements(core, initCs)
-            refined.capturing(cs)
+            refined.capturing(cs.changeOwner(ctx.owner))
 
         augmentConstructorType(ownType, capturedVars(cls) ++ capturedVars(sym))
           .showing(i"constr type $mt with $argTypes%, % in $cls = $result", capt)