mod 2, product of nx0 matrix and 0-dimensional vector: segfault

[jhpalmieri]

sage: matrix(GF(2), 11, 0) * vector(GF(2), 0)
------------------------------------------------------------------------
Unhandled SIGSEGV: A segmentation fault occurred in Sage.
This probably occurred because a *compiled* component of Sage has a bug
in it and is not properly wrapped with sig_on(), sig_off().
Sage will now terminate.
------------------------------------------------------------------------
Segmentation fault: 11

Component: linear algebra

Author: Travis Scrimshaw

Branch/Commit: ccfd5f8

Reviewer: John Palmieri

Issue created by migration from https://trac.sagemath.org/ticket/19378

[tscrim]

comment:1

This has to do with the dense GF(2) matrices:

sage: matrix(GF(2), 11, 0, sparse=True) * vector(GF(2), 0)
(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)

Here is a fix which just skips the multiplication of a vector times matrix since the result will be 0.

---

New commits:

ccfd5f8

Don't need to multiply if the vector is 0-dimensional.

[tscrim]

Branch: public/modules/gf2_matrix_times_0dim_vector-19378

[tscrim]

Author: Travis Scrimshaw

[tscrim]

Commit: ccfd5f8

[jhpalmieri]

comment:2

Looks good to me.

[jhpalmieri]

Reviewer: John Palmieri

[vbraun]

Changed branch from public/modules/gf2_matrix_times_0dim_vector-19378 to ccfd5f8