From 61e7be109f07d208be05b0567c78427bb80f7686 Mon Sep 17 00:00:00 2001
From: Tom Grigg <tomegrigg@gmail.com>
Date: Sat, 30 Jan 2021 16:28:46 -0800
Subject: [PATCH] Add regression test for #2941

---
 tests/pos/i2941.scala | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 tests/pos/i2941.scala

diff --git a/tests/pos/i2941.scala b/tests/pos/i2941.scala
new file mode 100644
index 000000000000..83d58d2c35f2
--- /dev/null
+++ b/tests/pos/i2941.scala
@@ -0,0 +1,17 @@
+trait FooBase {
+  type Bar >: Null <: BarBase { type This <: FooBase.this.Bar }
+  type This >: this.type <: FooBase { type This <: FooBase.this.This }
+
+  def derived(bar: Bar): This = ???
+}
+
+trait BarBase {
+  type This >: Null <: BarBase { type This <: BarBase.this.This }
+}
+
+object Test {
+  def bad(foo: FooBase): FooBase = foo match {
+    case foo: FooBase =>
+      foo.derived(???)  // Triggers infinite loop in TypeAssigner.avoid()
+  }
+}