From c9c4281159225c6a55bac7990a98c2805de6ef47 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=8BAndrzej=20Ressel?= <andrzej.ressel@gmail.com>
Date: Thu, 11 May 2023 23:37:05 +0200
Subject: [PATCH 1/3] Fix aliased type support in ImplicitRunInfo

---
 compiler/src/dotty/tools/dotc/typer/Implicits.scala | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/src/dotty/tools/dotc/typer/Implicits.scala b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
index f303bfbc5e19..f48963ea04e3 100644
--- a/compiler/src/dotty/tools/dotc/typer/Implicits.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
@@ -610,6 +610,8 @@ trait ImplicitRunInfo:
         else
           partSeen += t
           t.dealias match
+            case dealias if t ne dealias =>
+              traverse(wildApprox(dealias))
             case t: TypeRef =>
               if isAnchor(t.symbol) then
                 parts += t

From 027981ea658b8a9781a813a97d904db1bb83a9bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=8BAndrzej=20Ressel?= <andrzej.ressel@gmail.com>
Date: Thu, 11 May 2023 23:39:44 +0200
Subject: [PATCH 2/3] Add test

---
 tests/neg/i17305.scala | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 tests/neg/i17305.scala

diff --git a/tests/neg/i17305.scala b/tests/neg/i17305.scala
new file mode 100644
index 000000000000..8cee6d8cc97d
--- /dev/null
+++ b/tests/neg/i17305.scala
@@ -0,0 +1,37 @@
+trait Wrapper[A1] {
+  def use(a: A1 => Unit): Unit
+}
+
+trait Assertion[A2] {}
+
+def hideTypeInOut[A3](
+    c1: A3
+)(using
+    hider: HideAInOut[A3]
+): Wrapper[hider.Out] = ???
+
+def entryPoint(): Unit = {
+  hideTypeInOut(1L)
+    .use((pair) => myAssert(pair)(someAssertion(2))) // error Assertion[Int] instead of Assertion[Long]
+}
+
+private def myAssert[A4](a: A4)(assertion: Assertion[A4]): Unit = ()
+
+// This should be Unit or generic, but let compiler figure it out
+private def someAssertion(i: Int): Assertion[Int] = ???
+
+trait HideAInOut[-A] {
+  type Out
+  def get(left: A): Out
+}
+
+object HideAInOut {
+
+  type Out[HideA, HideB] = HideAInOut[HideA] { type Out = HideB }
+
+  given [GivenA]: HideAInOut.Out[GivenA, GivenA] =
+    new HideAInOut[GivenA] {
+      type Out = GivenA
+      def get(left: GivenA): Out = left
+    }
+}
\ No newline at end of file

From ae4007e6a41800c55665b0826a218e07c40f79ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=8BAndrzej=20Ressel?= <github@andrzejressel.pl>
Date: Thu, 11 May 2023 23:46:28 +0200
Subject: [PATCH 3/3] Fix comment

---
 tests/neg/i17305.scala | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/neg/i17305.scala b/tests/neg/i17305.scala
index 8cee6d8cc97d..f233abf9362e 100644
--- a/tests/neg/i17305.scala
+++ b/tests/neg/i17305.scala
@@ -17,7 +17,6 @@ def entryPoint(): Unit = {
 
 private def myAssert[A4](a: A4)(assertion: Assertion[A4]): Unit = ()
 
-// This should be Unit or generic, but let compiler figure it out
 private def someAssertion(i: Int): Assertion[Int] = ???
 
 trait HideAInOut[-A] {
@@ -34,4 +33,4 @@ object HideAInOut {
       type Out = GivenA
       def get(left: GivenA): Out = left
     }
-}
\ No newline at end of file
+}