optional doctest failure -- mistake in constructions guide wrt maxima interface

[williamstein]

This was clearly never tested, since eval always returns a string (it can't return nothing).

sage -t -long --optional devel/sage/doc/en/constructions/plotting.rst
**********************************************************************
File "/scratch/wstein/build/sage-4.0.2.alpha3/devel/sage-main/doc/en/constructions/plotting.rst", line 211:
    sage: maxima.eval('plotdf(x+y,[trajectory_at,2,-0.1]); ') #optional
Expected nothing
Got:
    '1'
**********************************************************************
1 items had failures:
   1 of   4 in __main__.example_11

CC: @maxthemouse

Component: packages: optional

Reviewer: Adam Webb

Issue created by migration from https://trac.sagemath.org/ticket/6319

[wdjoyner]

applies to 4.0.2.rc1

[wdjoyner]

comment:1

Attachment: trac_6319.patch.gz

Passes sage -tp 1 SAGE_ROOT/devel/sage/doc/en/constructions/. Also the builds sage -docbuild constructions html (resp., pdf) went fine.

[maxthemouse]

Reviewer: Adam Webb

[maxthemouse]

comment:2

I still get an error with sage -t -long --optional devel/sage/doc/en/constructions/plotting.rst, although it is with a return value of '0' instead of '1'. It passes sage -tp 1 SAGE_ROOT/devel/sage/doc/en/constructions/ for me as well.

The odd thing is that if I try the test from the sage command line I don't get the string returned i.e. the test passes. Or is it fine if 'sage -t' fails but the documentation is correct for what happens when you actually run it?

Adam