Fatal software bug?

[ijabbott]

That arg() bug seems to be in the Giac/Xcas code, so one for Bernard Parisse to look at.

Here is a giac session running in a Linux terminal. The angle_radian variable seems to have changed from 0 to 1 by itself after
arg(5+6.001i)

Code:

// Using locale /usr/share/locale/
// en_GB.utf8
// /usr/share/locale/
// giac
// UTF-8
// Maximum number of parallel threads 4
Added 26 synonyms
Welcome to giac readline interface, version 1.7.0
(c) 2001,2021 B. Parisse & others
Homepage http://www-fourier.ujf-grenoble.fr/~parisse/giac.html
Released under the GPL license 3.0 or above
See http://www.gnu.org for license details
May contain BSD licensed software parts (lapack, atlas, tinymt)
-------------------------------------------------
Press CTRL and D simultaneously to finish session
Type ?commandname for help
0>> angle_radian:=0
0
// Time 0.01
>> arg(5+6.001i)
50.6594818402
// Time 0
>> angle_radian
1
// Time 0
>> arg(5+6.1i)
0.884174755465
// Time 0
>>