#2349 integrate(sin(x)^2/x,x,minf,inf) gives not zero

[ivan antonovich]

ya@debian:~$ maxima
Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp CLISP 2.48 (2009-07-28)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) integrate(sin(x)^2/x,x,minf,inf);
Principal Value
log(- 1)
(%o1) - --------
2
(%i2)

sin(x)^2/x is odd function, so result of integration must be 0.

[Ted Woollett]

5.25.1gcl gave correct value (0 by symmetry)
(%i1) integrate(sin(x)^2/x,x,minf,inf);
Principal Value
(%o1) 0
(%i2) build_info()$

Maxima version: 5.25.1
Maxima build date: 10:2 9/6/2011
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8

5.26.0gcl gives effectively -%i*%pi/2

(%i1) integrate(sin(x)^2/x,x,minf,inf);
Principal Value
(%o1) -log(-1)/2
(%i2) float(%);
(%o2) -1.570796326794897*%i
(%i3) build_info()$
Maxima version: 5.26.0
Maxima build date: 22:48 1/15/2012
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8

[Dan Gildea]

Fixed in defint.lisp.
principal-value-integral: leave $logabs as is