From b1f070e51379c2d967262e083a352ec1548429ee Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Sun, 13 Jun 2021 18:03:10 +0200
Subject: [PATCH] Plug loophole for "no inlines with opaques" rule

Fixes #12814
---
 .../src/dotty/tools/dotc/core/SymDenotations.scala |  3 +--
 tests/neg/opaque-inline.scala                      | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 tests/neg/opaque-inline.scala

diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index ba094c587038..7f81fcf72597 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -651,8 +651,7 @@ object SymDenotations {
     def containsOpaques(using Context): Boolean = is(Opaque) && isClass
 
     def seesOpaques(using Context): Boolean =
-      containsOpaques ||
-      is(Module, butNot = Package) && owner.seesOpaques
+      containsOpaques || isClass && !is(Package) && owner.seesOpaques
 
     /** Is this the denotation of a self symbol of some class?
      *  This is the case if one of two conditions holds:
diff --git a/tests/neg/opaque-inline.scala b/tests/neg/opaque-inline.scala
new file mode 100644
index 000000000000..5507484231dd
--- /dev/null
+++ b/tests/neg/opaque-inline.scala
@@ -0,0 +1,14 @@
+
+object refined:
+  opaque type Positive = Int
+
+  object Positive extends PositiveFactory
+
+  trait PositiveFactory:
+    inline def apply(value: Int): Positive = f(value) // error: implementation restriction
+    def f(x: Positive): Positive = x
+
+@main def run: Unit =
+  import refined.*
+  val x = 9
+  val nine = Positive.apply(x)