From 6ce4fd08ed507d1229d9ecf186e1e28aebe9376d Mon Sep 17 00:00:00 2001
From: Matthias Wahl <matthiaswahl@m7w3.de>
Date: Sat, 5 Mar 2022 20:19:16 +0100
Subject: [PATCH] Add regression test for issue 2408.

Fixes #2408.
---
 test/libponyc-run/regression-2408/main.pony | 24 +++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 test/libponyc-run/regression-2408/main.pony

diff --git a/test/libponyc-run/regression-2408/main.pony b/test/libponyc-run/regression-2408/main.pony
new file mode 100644
index 0000000000..1e50aa95dc
--- /dev/null
+++ b/test/libponyc-run/regression-2408/main.pony
@@ -0,0 +1,24 @@
+interface SafeOps[T]
+  fun addc(t: T): (T, Bool)
+  fun subc(t: T): (T, Bool)
+
+class GenericSum[T: (Int & Integer[T] val & SafeOps[T])]
+  fun _plus_safe(x: T, y: T): (T, Bool) =>
+    x.addc(y)
+
+  fun sum(x: T, y: T): T ? =>
+    match _plus_safe(x, y)
+    // In the issue 2408 ponyc < 0.26 was reporting this pattern to never match
+    | (let res: T, false) => res
+    | (_, true) => error
+    else
+      // this else is only needed because ponyc does not recognize
+      // the match above as exhaustive
+      error
+    end
+
+actor Main
+  new create(env: Env) =>
+    try
+      GenericSum[U8].sum(1, 2)?
+    end