#3304 decfp do not work with "display2d:false"

[Takayuki Homma]

Maxima 5.39.0_2_g5a49f11_dirty http://maxima.sourceforge.net
using Lisp CLISP 2.49 (2010-07-07)
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) load(decfp);
WARNING: DEFUN/DEFMACRO: redefining function DIM-BIGFLOAT in
(snip many messages)
         Z:\home\dauti\Software\maxima-code\crosscompile-windows\build\maxima-prefix\src\maxima\src\binary-clisp\numeric.fas
0 errors, 12 warnings
(%o1)
 C:\maxima-5.39.0\share\maxima\5.39.0_2_g5a49f11_dirty\share\numeric\decfp.lisp
(%i2) display2d;
(%o2)                                true
(%i3) 1.23456789L0;
(%o3)                            1.23456789L0
(%i4) display2d:false;
(%o4) false
(%i5) 1.23456789L0;
(%o5) 7.359b0

[Takayuki Homma]

and...

(%i1) load(decfp);
(snip many messagess)
(%o1)
C:\maxima-5.39.0\share\maxima\5.39.0_2_g5a49f11_dirty\share\numeric\decfp.lisp
(%i2) 1.23456789L0;
(%o2) 1.23456789L0
(%i3) string(%);
(%o3) 7.359b0