# HG changeset patch
# User Serviscope Minor <serviscope_minor@verybigfrog.com>
# Date 1407512454 -3600
# Node ID 1ad621d894bac1cd6207d47bc504b57403171e11
# Parent  2ceb734a663f9a1bdcb69219378cfac714532aea
Fix set(gca, 'xtick', []) with gnuplot backend (bug #42936).

* __go_draw_axes__.m: initially "unset xtick;" is issued.
To avoid the ticks reappearing, all set xtick commands have to be omitted
if xtick == [], otherwise gnuplot fills in the ticks even if (say) only
the mirroring state is set.

diff -r 2ceb734a663f -r 1ad621d894ba scripts/plot/util/private/__go_draw_axes__.m
--- a/scripts/plot/util/private/__go_draw_axes__.m	Fri Aug 08 15:35:49 2014 +0100
+++ b/scripts/plot/util/private/__go_draw_axes__.m	Fri Aug 08 16:40:54 2014 +0100
@@ -1480,12 +1480,10 @@
         fprintf (plot_stream, "unset ytics; set y2tics %s nomirror\n",
                  axis_obj.tickdir);
         if (strcmpi (axis_obj.xaxislocation, "top"))
-          fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_x2tick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 12;\n");
         elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
-          fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_xtick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 9;\n");
         else # xaxislocation == zero
           fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
@@ -1498,16 +1496,13 @@
         fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                  axis_obj.tickdir);
         if (strcmpi (axis_obj.xaxislocation, "top"))
-          fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_x2tick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 6;\n");
         elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
-          fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_xtick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 3;\n");
         else # xaxislocation == zero
-          fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_xtick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 2;\n");
           fprintf (plot_stream, "set xzeroaxis lt -1 lw %f;\n",
                    axis_obj.linewidth);
@@ -1516,18 +1511,15 @@
         fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                  axis_obj.tickdir);
         if (strcmpi (axis_obj.xaxislocation, "top"))
-          fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_x2tick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 4;\n");
         elseif (strcmpi (axis_obj.xaxislocation, "bottom"))
-          fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
-                   axis_obj.tickdir);
+          maybe_do_xtick_mirror (plot_stream, axis_obj)
           fputs (plot_stream, "set border 1;\n");
         else # xaxislocation == zero
+          maybe_do_xtick_mirror (plot_stream, axis_obj)
           fprintf (plot_stream, "unset y2tics; set ytics %s nomirror\n",
                    axis_obj.tickdir);
-          fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
-                   axis_obj.tickdir);
           fputs (plot_stream, "unset border;\n");
           fprintf (plot_stream, "set xzeroaxis lt -1 lw %f;\n",
                    axis_obj.linewidth);
@@ -2139,6 +2131,13 @@
                     plot_stream, mirror, mono, axispos, tickdir, ticklength,
                     fontname, fontspec, interpreter, scale, sgn, gnuplot_term)
   persistent warned_latex = false;
+  
+  ## Avoid emitting anything if the tics are empty, because this undoes the
+  ## effect of the previous unset xtics and thereby adds back in the tics.
+  if (isempty (tics))
+    return;
+  endif
+
   if (mirror)
     mirror = "mirror";
   else
@@ -2614,3 +2613,17 @@
   endif
 endfunction
 
+function maybe_do_xtick_mirror (plot_stream, axis_obj)
+  if (! isempty(axis_obj.xtick))
+    fprintf (plot_stream, "unset x2tics; set xtics %s nomirror\n",
+                          axis_obj.tickdir);
+  endif
+endfunction
+
+function maybe_do_x2tick_mirror (plot_stream, axis_obj)
+  if (! isempty(axis_obj.xtick))
+    fprintf (plot_stream, "unset xtics; set x2tics %s nomirror\n",
+                          axis_obj.tickdir);
+  endif
+endfunction
+