[commit: ghc] master: Test Trac #10423 (b1b2b44)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/b1b2b44a86a34dae9eadd27af507c8b2c847ae2d/ghc

>---------------------------------------------------------------

commit b1b2b44a86a34dae9eadd27af507c8b2c847ae2d
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Tue Jun 2 11:38:28 2015 +0100

    Test Trac #10423


>---------------------------------------------------------------

b1b2b44a86a34dae9eadd27af507c8b2c847ae2d
 testsuite/tests/typecheck/should_compile/T10423.hs | 9 +++++++++
 testsuite/tests/typecheck/should_compile/all.T     | 1 +
 2 files changed, 10 insertions(+)

diff --git a/testsuite/tests/typecheck/should_compile/T10423.hs b/testsuite/tests/typecheck/should_compile/T10423.hs
new file mode 100644
index 0000000..5a8ff02
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T10423.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE FlexibleInstances, TypeFamilies, MultiParamTypeClasses #-}
+
+module T10423 where
+
+class Monad m => Testable m a
+
+newtype Prop m = MkProp (m Int)
+
+instance (Monad m, m ~ n) => Testable n (Prop m)
diff --git a/testsuite/tests/typecheck/should_compile/all.T b/testsuite/tests/typecheck/should_compile/all.T
index 2f257ea..12e2612 100644
--- a/testsuite/tests/typecheck/should_compile/all.T
+++ b/testsuite/tests/typecheck/should_compile/all.T
@@ -456,3 +456,4 @@ test('T10009', normal, compile, [''])
 test('T10390', normal, compile, [''])
 test('T8555', normal, compile, [''])
 test('T8799', normal, compile, [''])
+test('T10423', normal, compile, [''])