bug in TorsionQuadraticForm.normal_form()

[simonbrandhorst]

sage: L1=IntegralLattice(matrix([[-4,0,0],[0,4,0],[0,0,-2]]))
sage: AL1=L1.discriminant_group()
sage: L2=IntegralLattice(matrix([[-4,0,0],[0,-4,0],[0,0,2]]))
sage: AL2=L2.discriminant_group()
sage: AL1.normal_form()
Finite quadratic module over Integer Ring with invariants (2, 4, 4)
Gram matrix of the quadratic form with values in Q/2Z:
[1/4   0   0]
[  0 5/4   0]
[  0   0 1/2]
sage: AL2.normal_form()
Finite quadratic module over Integer Ring with invariants (2, 4, 4)
Gram matrix of the quadratic form with values in Q/2Z:
[7/4   0   0]
[  0 7/4   0]
[  0   0 1/2]

but:

sage: [x,y,z]=AL2.smith_form_gens()
sage: AL2.submodule_with_gens([x+z,y+x-2*z,x-2*z-2*y])
Finite quadratic module over Integer Ring with invariants (2, 4, 4)
Gram matrix of the quadratic form with values in Q/2Z:
[1/4   0   0]
[  0 5/4   0]
[  0   0 1/2]

Component: quadratic forms

Author: Simon Brandhorst

Branch/Commit: 2babaae

Reviewer: Paolo Menegatti

Issue created by migration from https://trac.sagemath.org/ticket/24864

[simonbrandhorst]

Author: Simon Brandhorst

[simonbrandhorst]

Branch: u/sbrandhorst/bug_in_torsionquadraticform_normal_form__

[simonbrandhorst]

Commit: 4825174

[simonbrandhorst]

New commits:

4825174

Fixed a bug in normal_form of a torsion_quadratic_module

[sagetrac-git]

Changed commit from 4825174 to 893ba1c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

893ba1c

trivial doc change

[sagetrac-pmenegat]

comment:5

I've done some tests and it seems ok to me

[simonbrandhorst]

Reviewer: Paolo Menegatti

[simonbrandhorst]

comment:7

Thank you for the review. If you review something, please remember to put your name in the reviewers field. :)

[sagetrac-pmenegat]

comment:8

I will remember for the next time

[vbraun]

comment:9

Merge conflict

[simonbrandhorst]

comment:10

I will merge in the next beta as soon as it is available.

[sagetrac-git]

Changed commit from 893ba1c to 2babaae

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

2babaae

Merge branch 'develop' into t/24864/bug_in_torsionquadraticform_normal_form__

[vbraun]

Changed branch from u/sbrandhorst/bug_in_torsionquadraticform_normal_form__ to 2babaae