random doctest failure in sage.plot.matrix_plot

[tornaria]

sage -t --long --random-seed=77574003112252338109572980105396911878 src/sage/plot/matrix_plot.py
**********************************************************************
File "src/sage/plot/matrix_plot.py", line 518, in sage.plot.matrix_plot.matrix_plot
Failed example:
    matrix_plot(random_matrix(P, 3, 3))
Expected:
    Traceback (most recent call last):
    ...
    TypeError: cannot convert nonconstant polynomial
Got:
    Graphics object consisting of 1 graphics primitive
**********************************************************************
1 item had failures:
   1 of  50 in sage.plot.matrix_plot.matrix_plot
    [71 tests, 1 failure, 11.28 s]
----------------------------------------------------------------------

I guess if one is really (un)lucky, the polynomial matrix is really constant. Indeed changing matrix_plot() for print() I get:

sage -t --random-seed=77574003112252338109572980105396911878 src/sage/plot/matrix_plot.py
**********************************************************************
File "src/sage/plot/matrix_plot.py", line 518, in sage.plot.matrix_plot.matrix_plot
Failed example:
    print(random_matrix(P, 3, 3))
Expected:
    Traceback (most recent call last):
    ...
    TypeError: cannot convert nonconstant polynomial
Got:
    [                 0  0.782649657440611                  0]
    [ 0.963470417368214 -0.498443274186489                  0]
    [                 0  0.419385875878395                  0]
**********************************************************************

Of course most random seeds yield nonconstant matrices so I was really lucky here...

Component: doctest coverage

Author: Michael Orlitzky

Branch/Commit: 553e115

Reviewer: Markus Wageringel

Issue created by migration from https://trac.sagemath.org/ticket/33154

[orlitzky]

New commits:

553e115

Trac #33154: fix random failure in sage.plot.matrix_plot.

[orlitzky]

Author: Michael Orlitzky

[orlitzky]

Commit: 553e115

[orlitzky]

Branch: u/mjo/ticket/33154

[mwageringel]

comment:2

Ok, LGTM.

[mwageringel]

Reviewer: Markus Wageringel

[slel]

comment:3

Setting milestone to 9.6 now that 9.5 is out.

[vbraun]

Changed branch from u/mjo/ticket/33154 to 553e115