diff options
Diffstat (limited to 'compiler/GHC/Core/Coercion.hs')
| -rw-r--r-- | compiler/GHC/Core/Coercion.hs | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Coercion.hs b/compiler/GHC/Core/Coercion.hs index 8a13ecb51b..06bc235913 100644 --- a/compiler/GHC/Core/Coercion.hs +++ b/compiler/GHC/Core/Coercion.hs @@ -2234,13 +2234,18 @@ liftEnvSubstRight = liftEnvSubst pSnd liftEnvSubst :: (forall a. Pair a -> a) -> Subst -> LiftCoEnv -> Subst liftEnvSubst selector subst lc_env - = composeTCvSubst (Subst emptyInScopeSet emptyIdSubstEnv tenv cenv) subst + = composeTCvSubst (Subst in_scope emptyIdSubstEnv tenv cenv) subst where pairs = nonDetUFMToList lc_env -- It's OK to use nonDetUFMToList here because we -- immediately forget the ordering by creating -- a VarEnv (tpairs, cpairs) = partitionWith ty_or_co pairs + -- Make sure the in-scope set is wide enough to cover the range of the + -- substitution (#22235). + in_scope = mkInScopeSet $ + tyCoVarsOfTypes (map snd tpairs) `unionVarSet` + tyCoVarsOfCos (map snd cpairs) tenv = mkVarEnv_Directly tpairs cenv = mkVarEnv_Directly cpairs |