infinite loop on gcd()



Here are two reported bugs that go away
when gcd : 'spmod.

bug 1020711
http://sourceforge.net/tracker/index.php?func=detail&aid=1020711&group_id=4933&atid=104933


bug 831445
http://sourceforge.net/tracker/index.php?func=detail&aid=831445&group_id=4933&atid=104933


The code for subres might be spotless, but the global
environment might be messed up; or it might be that
some code that subres calls is buggy; or ...

Bug 1020711 is

(%i1) integrate(sqrt(4*x^2 +4),x,0,1);
QUOTIENT by ZERO
 -- an error.  Quitting.  To debug this try DEBUGMODE(TRUE);
(%i2) integrate(sqrt(4*x^2 +4),x,0,1),gcd : 'spmod;
(%o2) asin(1)+sqrt(2)

Barton