From eb38e1f0fc38313ab17969a74664618900ace2e9 Mon Sep 17 00:00:00 2001
From: Julien Richard-Foy <julien@richard-foy.fr>
Date: Tue, 6 Jun 2023 15:53:42 +0200
Subject: [PATCH] Take into account the result type of inline implicit
 conversions unless they are transparent

Fixes #9685
---
 community-build/community-projects/munit      |  2 +-
 community-build/community-projects/specs2     |  2 +-
 .../dotty/tools/dotc/typer/ProtoTypes.scala   |  5 ++--
 tests/neg-macros/i9685bis.check               |  9 ++++++++
 tests/neg-macros/i9685bis.scala               | 23 +++++++++++++++++++
 5 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 tests/neg-macros/i9685bis.check
 create mode 100644 tests/neg-macros/i9685bis.scala

diff --git a/community-build/community-projects/munit b/community-build/community-projects/munit
index 92f3ad9e8261..55ae3caecf69 160000
--- a/community-build/community-projects/munit
+++ b/community-build/community-projects/munit
@@ -1 +1 @@
-Subproject commit 92f3ad9e8261b4c142a551baaf61ef5fed84d36a
+Subproject commit 55ae3caecf690c8f1a785d78798955c6042344ca
diff --git a/community-build/community-projects/specs2 b/community-build/community-projects/specs2
index 789f23b75db1..71d2510c3d7f 160000
--- a/community-build/community-projects/specs2
+++ b/community-build/community-projects/specs2
@@ -1 +1 @@
-Subproject commit 789f23b75db1cf7961d04468b21a2cc0d7ba32d8
+Subproject commit 71d2510c3d7f90773df3f4d1bd12374a40e50c20
diff --git a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
index bde279c582e6..8b04ca8dd75b 100644
--- a/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
+++ b/compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala
@@ -17,6 +17,7 @@ import Inferencing.*
 import ErrorReporting.*
 import util.SourceFile
 import TypeComparer.necessarySubType
+import dotty.tools.dotc.core.Flags.Transparent
 
 import scala.annotation.internal.sharable
 
@@ -105,14 +106,14 @@ object ProtoTypes {
       if !res then ctx.typerState.constraint = savedConstraint
       res
 
-    /** Constrain result with special case if `meth` is an inlineable method in an inlineable context.
+    /** Constrain result with special case if `meth` is a transparent inlineable method in an inlineable context.
      *  In that case, we should always succeed and not constrain type parameters in the expected type,
      *  because the actual return type can be a subtype of the currently known return type.
      *  However, we should constrain parameters of the declared return type. This distinction is
      *  achieved by replacing expected type parameters with wildcards.
      */
     def constrainResult(meth: Symbol, mt: Type, pt: Type)(using Context): Boolean =
-      if (Inlines.isInlineable(meth)) {
+      if (Inlines.isInlineable(meth) && meth.is(Transparent)) {
         constrainResult(mt, wildApprox(pt))
         true
       }
diff --git a/tests/neg-macros/i9685bis.check b/tests/neg-macros/i9685bis.check
new file mode 100644
index 000000000000..45e7f85aa30d
--- /dev/null
+++ b/tests/neg-macros/i9685bis.check
@@ -0,0 +1,9 @@
+-- [E008] Not Found Error: tests/neg-macros/i9685bis.scala:23:4 --------------------------------------------------------
+23 |  1.asdf // error
+   |  ^^^^^^
+   |  value asdf is not a member of Int, but could be made available as an extension method.
+   |
+   |  The following import might make progress towards fixing the problem:
+   |
+   |    import foo.Baz.toBaz
+   |
diff --git a/tests/neg-macros/i9685bis.scala b/tests/neg-macros/i9685bis.scala
new file mode 100644
index 000000000000..0023d4d719b4
--- /dev/null
+++ b/tests/neg-macros/i9685bis.scala
@@ -0,0 +1,23 @@
+package foo
+
+import scala.language.implicitConversions
+
+class Foo
+
+object Foo:
+
+  inline implicit def toFoo(x: Int): Foo = Foo()
+
+class Bar
+
+object Bar:
+  inline given Conversion[Int, Bar] with
+    def apply(x: Int): Bar = Bar()
+
+class Baz
+
+object Baz:
+  transparent inline implicit def toBaz(x: Int): Baz = Baz()
+
+object Usage:
+  1.asdf // error