The attribute _vector of H and V representation is exposed

[jplab]

Following the sage devel thread:

https://groups.google.com/forum/#!topic/sage-devel/iHvm9wfvr5g

The following code changes the internal attributes of V and H representations:

sage: C = polytopes.cube()
sage: C.vertices()[0].vector()[0] = 3
sage: C.vertices()[0]
A vertex at (3, -1, -1)

and:

sage: C.inequalities()[0].A()[2] = 5
sage: C.inequalities()[0]
An inequality (0, 0, 5) x + 1 >= 0

As mentioned in the __hash__ function of the file representation.py inside of the folder src/sage/geometry/polyhedron/, the attribute _vector is not immutable, due to the way it is constructed and its requirement to change in the current setup.

This ticket provides a small fix that creates a copy of the vectors.

CC: @videlec @jhpalmieri

Component: geometry

Keywords: polytopes

Author: Jean-Philippe Labbé

Branch/Commit: d969c02

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/27709

[jplab]

Commit: d969c02

[jplab]

Branch: u/jipilab/repr_exposed

[jplab]

New commits:

d969c02

Fixed the exposed _vector

[sagetrac-git]

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

8768f2e

Removed old deprecation warnings

[sagetrac-git]

Changed commit from d969c02 to 8768f2e

[videlec]

comment:3

Please remove the deprecation in a distinct ticket.

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

comment:4

LGTM.

[vbraun]

comment:5

See patchbot

[tscrim]

comment:6

Whoops, we both missed a line.

[sagetrac-git]

Changed commit from 8768f2e to d969c02

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

[jplab]

comment:8

As suggested, I removed the deprecation warning removal from the branch.

The failing doctest is related to that.

[vbraun]

Changed branch from u/jipilab/repr_exposed to d969c02