From 07622a14108f77cbdf4356a9edfb1ec666392045 Mon Sep 17 00:00:00 2001
From: Eugene Flesselle <eugene@flesselle.net>
Date: Fri, 12 Apr 2024 11:12:58 +0200
Subject: [PATCH] Allow SAM types to contain multiple refinements

---
 compiler/src/dotty/tools/dotc/core/Types.scala | 2 +-
 tests/run/i18315.scala                         | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
index ba48b6a0f2e6..47ba9833fc2f 100644
--- a/compiler/src/dotty/tools/dotc/core/Types.scala
+++ b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -5965,7 +5965,7 @@ object Types extends TypeUtils {
       def withRefinements(toType: Type, fromTp: Type): Type = fromTp.dealias match
         case RefinedType(fromParent, name, info: AliasingBounds) if tp0.member(name).exists =>
           val parent1 = withRefinements(toType, fromParent)
-          RefinedType(toType, name, info)
+          RefinedType(parent1, name, info)
         case _ => toType
       val tp = withRefinements(tp0, origTp)
 
diff --git a/tests/run/i18315.scala b/tests/run/i18315.scala
index 85824920efbd..51a80420632d 100644
--- a/tests/run/i18315.scala
+++ b/tests/run/i18315.scala
@@ -7,9 +7,16 @@ trait Sam2:
   type T
   def apply(x: T): T
 
+trait Sam3:
+  type T
+  type U
+  def apply(x: T): U
+
 object Test:
   def main(args: Array[String]): Unit =
     val s1: Sam1 { type T = String } = x => x.trim
     s1.apply("foo")
     val s2: Sam2 { type T = Int } = x => x + 1
     s2.apply(1)
+    val s3: Sam3 { type T = Int; type U = String } = x => x.toString
+    s3.apply(2)