--- title: "Magma V2.19-3 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.19-3.html" source: "https://docs.magma-maths.org/patchnotes/2.19-3.md" --- # Magma V2.19-3 Patch Notes ## Aggregates - Fixed a bug in multiset constructors that could cause a later item in the constructor to replace an earlier one rather than augment it. This would only apply when the later item caused the multiset universe to enlarge and both items have the same value in this larger universe. - Fixed a potential memory leak when using associative arrays and indexed assignments in such a way that the associative array’s universe needs to change. ## Algebraic Number Fields - A bug in the computation of `Subfields` of a number field defined by a non-monic polynomial has been fixed. ## Clifford Algebras - A crash in [`CliffordAlgebra`](../Algebras/CliffordAlgebras/creation.md#function-cliffordalgebra-algmatelt) due to a missing universe for a null sequence has been fixed. Bug reported by Markus Kirschmer. ## Coding Theory - Fixed occasional excessive memory use when constructing large linear codes. This could also show up when making subspaces of vector spaces. - Improved internal memory handling used by [`Words`](../CodingTheory/AdditiveCodes/structural.md#function-words-code-rngintelt) for codes of large dimension. - A bug in [`Words`](../CodingTheory/AdditiveCodes/structural.md#function-words-code-rngintelt) which occasionally included the zero vector has been fixed. Reported by P. Lisonek. - Fixed the name of the vararg `NumWords` in the descriptions of some intrinsics (was erroneously given as `Cutoff`). - Fixed a very minor memory leak in [`NumberOfWords`](../CodingTheory/AdditiveCodes/structural.md#function-numberofwords-code-rngintelt). ## Commutative Algebra - A bug in `Radical` has been fixed. Reported by E. Rains. ## Cyclotomic Fields - A crash in `RootOfUnity` when the degree of the field is less than half the order of the field has been fixed. - An error in the `MultiplicativeGroup` map has been fixed. This has fixed a crash in computing `AbsolutelyIrreducibleModules` of a pc-group which was reported by Eamonn O’Brien. ## Forms - Code to construct the Wall form of a unitary matrix, which was missing from the main release, is now included. ## Graphs - A crash in [`EquitablePartition`](../Combinatorics/Graphs/path-circuit-graph.md#function-equitablepartition-grphvert-grphund) has been fixed. ## Groups - A crash computing normal subgroups of a permutation group has been fixed. Bug reported by Peter Mueller. - An error in the stored order of a `NormalClosure` within permutation groups has been fixed. Bug reported by Peter Mueller. - An crash when computing the `Core` of a subgroup of a permutation group has been fixed. Bug reported by Peter Mueller. - A crash when computing `IrreducibleModules` of pc-group has been fixed. Bug reported by Primoz Potocnik. - A crash when computing [`DistinctExtensions`](../FiniteGroups/CohomologyAndExtensions/extensions-2.md#function-grpcoh-distinctextensions) of pc-group has been fixed. Bug reported by Primoz Potocnik. - A problem when computing normalizers of matrix subgroups has been fixed. This has improved computing subgroups of a matrix group in some cases - A crash in `Descedants` of a p-group has been fixed. Bug reported by Michael Bush. - A new parameter `MaxAuts` ahs been added to [`GeneratepGroups`](../FiniteGroups/FiniteSolubleGroups/p-groups.md#function-generatepgroups-rngintelt-rngintelt-rngintelt) and [`Descendants`](../FiniteGroups/FiniteSolubleGroups/p-groups.md#function-descendants-grppc) to compute maximally automorphic descendants. Code supplied by Eamonn O’Brien. - An error/crash when computing conjugacy classes of a general linear group has been fixed. This bug was reported, as a crash in `PermutationCharacter`, by Alex Bartel. - A crash computing `MaximalSubgroups` has been fixed. Bug reported by Andreas-Stephan Elsenhans. ## Lattices and Quadratic Forms - A bug with [`WittInvariants`](../LatticesQuadraticForms/QuadraticForms/local-invariants.md#function-wittinvariants-rngmpolelt) and allied intrinsics was fixed, where the bad primes were computed from the determinant, and when the matrix was over the rationals, this need not be correct. Reported by Stefan Hoeppner. ## Lie Theory - A crash when computing [`WeightsAndMultiplicities`](../LieTheory/RepresentationsOfLieGroupsAndAlgebras/representation-properties.md#function-weightsandmultiplicities-lierepdec) of a root datum has been fixed. Bug reported by Emmanuel Kowalski. - A crash in the [`Plethysm`](../LieTheory/RepresentationsOfLieGroupsAndAlgebras/representation-properties.md#function-plethysm-rootdtm-seqenum-modtuprngelt) function has been fixed. Bug reported by Robert Zeier. ## Modules - A bug in `hom` for non-free modules has been fixed. Reported by M. Bright. ## Quaternion Algebras - A bug in the computation of normalizers of definite quaternion orders over number rings has been fixed.