[Maxima-commits] CVS: maxima/src defint.lisp,1.82,1.83

[Dan G. <dg...@us...>]

Update of /cvsroot/maxima/maxima/src
In directory sfp-cvsdas-4.v30.ch3.sourceforge.com:/tmp/cvs-serv21318

Modified Files:
	defint.lisp 
Log Message:
sin-cos-intsubs1: calling intsubs on numerator may incorrectly
signal a divergent integral.  Example:
integrate(cos(x)^2 * (1 + sin(x)^2)^-3,x,0,%pi/2);


Index: defint.lisp
===================================================================
RCS file: /cvsroot/maxima/maxima/src/defint.lisp,v
retrieving revision 1.82
retrieving revision 1.83
diff -u -d -r1.82 -r1.83
--- defint.lisp	21 Aug 2010 16:51:38 -0000	1.82
+++ defint.lisp	2 Oct 2010 17:24:36 -0000	1.83
@@ -2028,20 +2028,8 @@
 
 (defun sin-cos-intsubs1 (exp)
   (let* ((rat-exp ($rat exp))
-	 (num (pdis (cadr rat-exp)))
 	 (denom (pdis (cddr rat-exp))))
-    (cond ((not (equal (intsubs num ll ul) 0.))
-	   (intsubs exp ll ul))
-	  ;; Why do we want to return zero when the denom is not zero?
-	  ;; That doesn't seem to make sense to me (rtoy).  Checking
-	  ;; for a zero denominator makes sense, but what we should
-	  ;; return in that case?  0 seems like a bad choice.  $inf or
-	  ;; $undefined seem like better choices.  Or maybe just
-	  ;; signaling an error?
-	  #+nil
-	  ((not (equal ($asksign denom) '$zero))
-	   0)
-	  ((equal ($csign denom) '$zero)
+    (cond ((equal ($csign denom) '$zero)
 	   '$undefined)
 	  (t (intsubs exp ll ul)))))