From 19a211e2d54d4f07419ef92b0e5000883aa64215 Mon Sep 17 00:00:00 2001
From: Tommy Hofmann <thofma@gmail.com>
Date: Fri, 14 Jul 2023 19:04:32 +0200
Subject: [PATCH] Wrap saturation2 and use it for Laurent polynomials (#2562)

---
 experimental/Laurent/src/Laurent.jl |  2 +-
 src/Rings/mpoly-ideals.jl           | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/experimental/Laurent/src/Laurent.jl b/experimental/Laurent/src/Laurent.jl
index c94e4a350aad..3fbb71e50cd4 100644
--- a/experimental/Laurent/src/Laurent.jl
+++ b/experimental/Laurent/src/Laurent.jl
@@ -160,7 +160,7 @@ function preimage(f::MPolyAnyMap{X, <: LaurentMPolyRing, Y, Z}, I::LaurentMPolyI
                          # the Laurent polynomial ring R
     _R = base_ring(II)
     for g in gens(_R)
-      II = saturation(II, g*_R)
+      II = Oscar._saturation2(II, g*_R)
     end
     # We need to translate to an ideal of R
     return ideal(R, map(x -> map_coefficients(identity, x, parent = R), gens(II)))
diff --git a/src/Rings/mpoly-ideals.jl b/src/Rings/mpoly-ideals.jl
index 9618230a4c4a..e0485d88fe85 100644
--- a/src/Rings/mpoly-ideals.jl
+++ b/src/Rings/mpoly-ideals.jl
@@ -276,6 +276,16 @@ function saturation(I::MPolyIdeal{T}, J::MPolyIdeal{T}) where T
   K, _ = Singular.saturation(I.gens.S, J.gens.S)
   return MPolyIdeal(base_ring(I), K)
 end
+
+# the following is corresponding to saturation2 from Singular
+# TODO: think about how to use use this properly/automatically
+function _saturation2(I::MPolyIdeal{T}, J::MPolyIdeal{T}) where T
+  singular_assure(I)
+  singular_assure(J)
+  K, _ = Singular.saturation2(I.gens.S, J.gens.S)
+  return MPolyIdeal(base_ring(I), K)
+end
+
 #######################################################
 @doc raw"""
     saturation_with_index(I::MPolyIdeal{T}, J::MPolyIdeal{T}) where T