polgalois bug fix

[Iwao KIMURA <iwao@math.tsukuba.ac.jp>]

Dear developers,

My acquaintance told me that polgaois() in 2.0.12.alpha is strange:
--------------------
? polgalois(x^4-x^3-3*x^2/2+3*x+1/2)
  ***   segmentation fault: bug in GP (please report).
--------------------
He tested on SunOS4.1.4 on `sparcv8 (C portable kernel) 32-bit
version'.  I also could reproduce this phenomenon on my FreeBSD
box. This seems to be fixed by the following modification.

--------------------
amaki: {164} diff -uBb src/basemath/base1.c.orig src/basemath/base1.c
--- src/basemath/base1.c.orig   Tue Dec 15 23:42:20 1998
+++ src/basemath/base1.c        Tue Dec 15 23:42:40 1998
@@ -215,7 +215,7 @@
     p1 = mulii(lead,p1);
     res[n] = lmulii(p1,(GEN)pol[n]);
   }
-  if (lead) *ptlead = lead; return res;
+  if (ptlead) *ptlead = lead; return res;
 }
 
 /* compute x1*x2^2 + x2*x3^2 + x3*x4^2 + x4*x1^2 */
--------------------

;#			     Iwao KIMURA			;#
;#		      Institute of Mathematics,			;#
;#		University of TSUKUBA, IBARAKI, JAPAN.		;#