figure bug

[Daniel J Sebald]

figure ('visible', 'off');

should produce an error, which it does.  (At least I think it should, unless a 
new figure is supposed to be created and then its parameter set.)  But it isn't 
a correct kind of error.

octave:8> figure ('visible', 'off');
error: `f' undefined near line 56 column 12
error: evaluating argument list element number 1
error: evaluating if command near line 55, column 5
error: evaluating if command near line 54, column 3
error: called from `figure' in file 
`/usr/local/share/octave/2.9.9+/m/plot/figure.m'

The attached patch should be incrementally better.  (Not sure what function 
variable convention is.)

Dan

--- /usr/local/share/octave/2.9.9+/m/plot/figure.m      2007-02-08 
11:50:56.000000000 -0600
+++ figure.m    2007-02-12 04:02:17.000000000 -0600
@@ -18,7 +18,7 @@
 ## 02110-1301, USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} figure (@var{n})
+## @deftypefn {Function File} {} figure 
(@var{n},@var{"param1"},@var{"setting1"},...)
 ## Set the current plot window to plot window @var{n}.  If @var{n} is
 ## not specified, the next available window number is chosen.
 ## @end deftypefn
@@ -45,6 +45,8 @@
     else
       error ("figure: expecting figure handle or figure number");
     endif
+  else
+    print_usage();
   endif
 
   if (nargout > 0)