Fix bug in Gröbner basis caching

Author: wegank

src/algorithms/groebner-bases.jl

@@ -128,7 +128,12 @@ function groebner_basis(
         worker_pool::Union{Nothing,AbstractWorkerPool}=nothing,
         info_level::Int=0
         )
-    return get!(I.gb, eliminate) do
+    key = if intersect && complete_reduction && !normalize && truncate_lifting == 0
+        eliminate
+    else
+        reinterpret(Int64, hash((eliminate, intersect, complete_reduction, normalize, truncate_lifting)) | 0x8000000000000000)
+    end
+    return get!(I.gb, key) do
         _core_groebner_basis(I, initial_hts = initial_hts, nr_thrds = nr_thrds,
                              max_nr_pairs = max_nr_pairs, la_option = la_option,
                              eliminate = eliminate, intersect = intersect,

test/algorithms/groebner-bases.jl

@@ -4,7 +4,7 @@ using Distributed
     R, (x,y,z) = polynomial_ring(GF(101),["x","y","z"], internal_ordering=:degrevlex)
     I = Ideal([x+2*y+2*z-1, x^2+2*y^2+2*z^2-x, 2*x*y+2*y*z-y])
     G = groebner_basis(I)
-    H = MPolyRingElem[
+    H = FqMPolyRingElem[
          x + 2*y + 2*z + 100
          y*z + 82*z^2 + 10*y + 40*z
          y^2 + 60*z^2 + 20*y + 81*z
@@ -14,14 +14,14 @@ using Distributed
     @test I.gb[0] == H
 
     G = groebner_basis(I, eliminate=2)
-    H = MPolyRingElem[
+    H = FqMPolyRingElem[
          z^4 + 38*z^3 + 95*z^2 + 95*z
         ]
     @test G == H
 
     I = Ideal([x+2*y+2*z-1, x^2+2*y^2+2*z^2-x, 2*x*y+2*y*z-y])
     G = groebner_basis(I, eliminate=2, intersect=false)
-    H = MPolyRingElem[
+    H = FqMPolyRingElem[
         z^4 + 38*z^3 + 95*z^2 + 95*z
         30*z^3 + 32*z^2 + y + 87*z
         41*z^3 + 37*z^2 + x + 30*z + 100
@@ -30,6 +30,9 @@ using Distributed
 
     @test_throws ErrorException eliminate(I,0)
     L = eliminate(I,2)
+    H = FqMPolyRingElem[
+        z^4 + 38*z^3 + 95*z^2 + 95*z
+    ]
     @test L == H
     @test I.gb[2] == H