Integral crash

[Albert Chan]

Thanks rawi,

That narrowed down the bug from Dec 2021 to Sep 2022 (latest XCas 1.9.0-22)

while we are at it, there is an annoying bug, which old XCas 1.5.0 does not have.

XCas> plot([sin(x), cos(x)], x = 0 .. 2*pi, color=[blue, red])
XCas> plot([sin(x), cos(x)], x = 0 .. 2*pi, legend=["sin", "cos"])

1st plot, both curves are drawn in blue
2nd plot, both curves have legend ["sin"

To make the curves match color/legend, we have to put both in.

XCas> plot([sin(x), cos(x)], x = 0 .. 2*pi, color=[blue,red], legend=["sin", "cos"])