Don't use explicit figure number for tests to avoid interference with any figures opened by user. (plot/allchild.m, plot/ancestor.m, plot/cla.m, plot/clf.m, plot/close.m, plot/findall.m, plot/findobj.m, plot/gca.m, plot/gcf.m, plot/hggroup.m, plot/isfigure.m, plot/line.m, plot/loglog.m, plot/patch.m, plot/semilogx.m, plot/semilogy.m, plot/surface.m, plot/view.m, plot/whitebg.m, plot/xlim.m, plot/ylim.m, plot/zlim.m): Don't use explicit figure numer 1232 any more.

--- a/scripts/plot/gca.m
+++ b/scripts/plot/gca.m
@@ -51,7 +51,7 @@
 endfunction
 
 %!test
-%! hf = figure (1232, "visible", "off");
+%! hf = figure ("visible", "off");
 %! ax = axes;
 %! unwind_protect  
 %!   assert (gca, ax);