--- title: "Magma V2.19-10 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.19-10.html" source: "https://docs.magma-maths.org/patchnotes/2.19-10.md" --- # Magma V2.19-10 Patch Notes ## Algebraic Curves - Added proper error messaging for some cases in the suite of gonal maps functionality - in particular, in [`Genus6GonalMap`](../AlgebraicGeometry/AlgebraicCurves/arith-2.md#function-genus6gonalmap-crv) - where there is a failure in small characteristics because of implementational problems in explicitly splitting a Lie Algebra. Reported by S. Kochinke for an example in characteristic 3. ## Algebraic Function Fields - Elements are now constructed with respect to an equation order basis, as this is considerably more efficient for arithmetic. - A crash has been fixed in forming the sum of two orders (in the case where one summand is an equation order). - A fix has been made in `GaloisGroup` for polynomials over function fields. - `LPolynomial` and `ZetaFunction` are now available for function fields with larger genus or constant fields than before. Reported by Liu Xiaogang. ## Algebraic Number Fields - A problem has been fixed which caused [`AbsoluteAlgebra`](../ArithmeticGeometry/EllipticCurvesOverQAndNumberFields/over_anf.md#function-absolutealgebra-rngupolres) to fail to terminate. Reported by N. Freitas. - A problem in `ClassGroup` has been fixed; it failed to terminate for a certain (easy) example. Reported by D. Smertnig. - A fix has been made in `GaloisGroup`, in the case of non-monic reducible polynomials. - A crash has been fixed in forming the sum of two orders (in the case where one summand is an equation order). - A crash in some [`SolveByRadicals`](../GlobalFields/AlgebraicFunctionFields/galois.md#function-solvebyradicals-rngupolelt) computations has been fixed. - A crash has been fixed in `AbsoluteField` in the case of a linear extension by a non-integral polynomial. - A memory leak has been fixed in `IsSquare` for elements of number fields. Reported by L. Dembélé. ## Basic Algebras - Some bugs have been fixed and some methods have been improved. Code supplied by J.F. Carlson. ## Commutative Algebra - A simple problem with `meet` for affine algebras has been fixed. Reported by C. Quitte. - Rational function fields over fields of fractions of affine algebras are now supported properly. ## Elliptic Curves - A bug has been fixed in the elliptic curve `Chabauty` routine, where it returned with too small a set of points. Reported by N. Freitas and M. Stoll. ## Groups - A crash when constructing subgroups of a finitely presented group has been fixed. This crash was found by an unknown user of the online calculator. - A memory leak in the `Subgroups` class of functions for matrix and permutation groups has been fixed. ## Lattices - A crash when computing the automorphism group of a lattice has been fixed. The bug was due to the [`ShortestVectorsMatrix`](../LatticesQuadraticForms/Lattices/enumeration.md#function-shortestvectorsmatrix-lat) of the lattice being possibly incorrect when it is very large. This problem has been fixed. Bug reported by G. Nebe. ## Modular Curves - The [`CuspPlaces`](../ModularArithmeticGeometry/SmallModularCurves/cusps_small_mod_crv.md#function-cuspplaces-crv-rngintelt-rngintelt) intrinsic in the small modular curves package now returns a sequence in all cases. Reported by S. Siksek. ## Modules over Dedekind Domains - A fix has been made to the construction of a module from a sequence of `ModRng` elements. ## Polynomial Rings - Coercion into a quotient polynomial ring has been fixed so that elements from recursive base rings are handled properly. Reported by N. Bruin. ## Series Rings - The handling of zero roots of polynomials over series rings has been improved, sometimes zero roots were listed twice. - A crash has been fixed in `HasRoot` for polynomials over series rings when a root could not be computed.