3 files changed, 58 insertions, 0 deletions
diff --git a/testsuite/tests/simplCore/should_compile/T23083.hs b/testsuite/tests/simplCore/should_compile/T23083.hs
new file mode 100644
index 0000000000..1f181217a4
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T23083.hs
@@ -0,0 +1,10 @@
+module T23083 where
+
+-- Just ($), but NOINLINE so that we don't inline it eagerly, subverting the
+-- test case
+($$) :: (a -> b) -> a -> b
+($$) f x = f x
+{-# NOINLINE ($$) #-}
+
+g :: ((Integer -> Integer) -> Integer) -> (Integer -> Integer) -> Integer
+g f h = f (h `seq` (h $$))
diff --git a/testsuite/tests/simplCore/should_compile/T23083.stderr b/testsuite/tests/simplCore/should_compile/T23083.stderr
new file mode 100644
index 0000000000..61151890e5
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T23083.stderr
@@ -0,0 +1,47 @@
+
+==================== CorePrep ====================
+Result size of CorePrep = {terms: 34, types: 34, coercions: 0, joins: 0/1}
+
+-- RHS size: {terms: 6, types: 5, coercions: 0, joins: 0/0}
+(T23083.$$) [InlPrag=NOINLINE] :: forall a b. (a -> b) -> a -> b
+[GblId, Arity=2, Str=<1C(1,L)><L>, Unf=OtherCon []]
+(T23083.$$) = \ (@a) (@b) (f [Occ=Once1!] :: a -> b) (x [Occ=Once1] :: a) -> f x
+
+-- RHS size: {terms: 12, types: 12, coercions: 0, joins: 0/1}
+T23083.g :: ((GHC.Num.Integer.Integer -> GHC.Num.Integer.Integer) -> GHC.Num.Integer.Integer) -> (GHC.Num.Integer.Integer -> GHC.Num.Integer.Integer) -> GHC.Num.Integer.Integer
+[GblId, Arity=2, Str=<1C(1,L)><ML>, Unf=OtherCon []]
+T23083.g
+  = \ (f [Occ=Once1!] :: (GHC.Num.Integer.Integer -> GHC.Num.Integer.Integer) -> GHC.Num.Integer.Integer) (h [Occ=OnceL1] :: GHC.Num.Integer.Integer -> GHC.Num.Integer.Integer) ->
+      let {
+        sat [Occ=Once1] :: GHC.Num.Integer.Integer -> GHC.Num.Integer.Integer
+        [LclId]
+        sat = \ (eta [Occ=Once1] :: GHC.Num.Integer.Integer) -> case h of h1 [Occ=Once1] { __DEFAULT -> T23083.$$ @GHC.Num.Integer.Integer @GHC.Num.Integer.Integer h1 eta } } in
+      f sat
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+T23083.$trModule4 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+T23083.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+T23083.$trModule3 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+T23083.$trModule3 = GHC.Types.TrNameS T23083.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+T23083.$trModule2 :: GHC.Prim.Addr#
+[GblId, Unf=OtherCon []]
+T23083.$trModule2 = "T23083"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+T23083.$trModule1 :: GHC.Types.TrName
+[GblId, Unf=OtherCon []]
+T23083.$trModule1 = GHC.Types.TrNameS T23083.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+T23083.$trModule :: GHC.Types.Module
+[GblId, Unf=OtherCon []]
+T23083.$trModule = GHC.Types.Module T23083.$trModule3 T23083.$trModule1
+
+
+
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index b1ec7473ff..bd6a862ba9 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -477,6 +477,7 @@ test('T23012', normal, compile, ['-O'])
 test('RewriteHigherOrderPatterns', normal, compile, ['-O -ddump-rule-rewrites -dsuppress-all -dsuppress-uniques'])
 test('T23024', normal, multimod_compile, ['T23024', '-O -v0'])
 test('T23026', normal, compile, ['-O'])
+test('T23083', [ grep_errmsg(r'eta.+::.+Integer') ], compile, ['-O -ddump-prep -dsuppress-uniques -dppr-cols=99999'])
 test('T23267', [expect_broken(23267), only_ways(['ghci']), extra_hc_opts('-fno-unoptimized-core-for-interpreter -fspec-constr')], ghci_script, ['T23267.script'])
 test('T23362', normal, compile, ['-O'])
 test('T23307', normal, compile, ['-O -ddump-simpl -dno-typeable-binds -dsuppress-uniques'])