From cb764b04c640d7a8e592876956c0a454567c3281 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Fri, 11 Mar 2022 14:22:19 +0100
Subject: [PATCH] Generate opaque proxies also for base classes

Fixes #14656
---
 compiler/src/dotty/tools/dotc/typer/Inliner.scala |  2 +-
 tests/pos/i14656.scala                            | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 tests/pos/i14656.scala

diff --git a/compiler/src/dotty/tools/dotc/typer/Inliner.scala b/compiler/src/dotty/tools/dotc/typer/Inliner.scala
index 0a762356869f..b4dda58e6a17 100644
--- a/compiler/src/dotty/tools/dotc/typer/Inliner.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Inliner.scala
@@ -597,7 +597,7 @@ class Inliner(call: tpd.Tree, rhsToInline: tpd.Tree)(using Context) {
   def addOpaqueProxies(tp: Type, span: Span, forThisProxy: Boolean)(using Context): Unit =
     tp.foreachPart {
       case ref: TermRef =>
-        for cls <- ref.widen.classSymbols do
+        for cls <- ref.widen.baseClasses do
           if cls.containsOpaques
              && (forThisProxy || inlinedMethod.isContainedIn(cls))
              && mapRef(ref).isEmpty
diff --git a/tests/pos/i14656.scala b/tests/pos/i14656.scala
new file mode 100644
index 000000000000..9f5e11a71116
--- /dev/null
+++ b/tests/pos/i14656.scala
@@ -0,0 +1,12 @@
+
+trait BigDecimalNewType:
+  opaque type Type = BigDecimal
+  def apply(value: BigDecimal): Type = value
+  extension (self: Type)
+    def value: BigDecimal = self
+    inline def +(y: Type): Type = apply(self.value + y.value)
+
+object Amount extends BigDecimalNewType {
+  val x = Amount(0)
+  val y = (x + x) + x
+}
\ No newline at end of file