Disable miter limit in SVG, PS and Agg backends

lib/matplotlib/backends/backend_ps.py

@@ -1189,6 +1189,8 @@ def print_figure_impl():
             print("%s translate"%_nums_to_str(xo, yo), file=fh)
             if rotation: print("%d rotate"%rotation, file=fh)
             print("%s clipbox"%_nums_to_str(width*72, height*72, 0, 0), file=fh)
+            # Disable any sort of miter limit
+            print("%s setmiterlimit" % 100000, file=fh)
 
             # write the figure
             content = self._pswriter.getvalue()
@@ -1338,6 +1340,8 @@ def write(self, *kl, **kwargs):
             #print >>fh, "gsave"
             print("%s translate"%_nums_to_str(xo, yo), file=fh)
             print("%s clipbox"%_nums_to_str(width*72, height*72, 0, 0), file=fh)
+            # Disable any sort of miter limit
+            print("%d setmiterlimit" % 100000, file=fh)
 
             # write the figure
             print(self._pswriter.getvalue(), file=fh)

lib/matplotlib/backends/backend_svg.py

@@ -297,7 +297,10 @@ def _write_default_style(self):
         writer = self.writer
         default_style = generate_css({
             'stroke-linejoin': 'round',
-            'stroke-linecap': 'butt'})
+            'stroke-linecap': 'butt',
+            # Disable the miter limit.  100000 seems to be close to
+            # the maximum that renderers support before breaking.
+            'stroke-miterlimit': '100000'})
         writer.start('defs')
         writer.start('style', type='text/css')
         writer.data('*{%s}\n' % default_style)

lib/matplotlib/tests/test_colorbar.py

@@ -6,6 +6,7 @@
 import numpy as np
 from numpy import ma
 import matplotlib
+from matplotlib import rc_context
 from matplotlib.testing.decorators import image_comparison, cleanup
 import matplotlib.pyplot as plt
 from matplotlib import rcParams
@@ -258,27 +259,27 @@ def test_colorbarbase():
     baseline_images=['colorbar_closed_patch'],
     remove_text=True)
 def test_colorbar_closed_patch():
-    fig = plt.figure(figsize=(8,6))
+    fig = plt.figure(figsize=(8, 6))
     ax1 = fig.add_axes([0.05, 0.85, 0.9, 0.1])
     ax2 = fig.add_axes([0.1, 0.65, 0.75, 0.1])
     ax3 = fig.add_axes([0.05, 0.45, 0.9, 0.1])
     ax4 = fig.add_axes([0.05, 0.25, 0.9, 0.1])
     ax5 = fig.add_axes([0.05, 0.05, 0.9, 0.1])
 
-    cmap = cm.jet
-    cmap.set_under('w')
-    cmap.set_over('w')
-
-    im = ax1.pcolormesh(np.linspace(0,10,16).reshape((4,4)))
+    cmap = get_cmap("RdBu", lut=5)
 
-    plt.colorbar(im,cax=ax2,cmap=cmap,orientation='horizontal',
-                 extend='both',extendfrac=0.5)
-    plt.colorbar(im,cax=ax3,cmap=cmap,orientation='horizontal',
-                 extend='both',)
-    plt.colorbar(im,cax=ax4,cmap=cmap,orientation='horizontal',
-                 extend='both',extendrect=True)
-    plt.colorbar(im,cax=ax5,cmap=cmap,orientation='horizontal',
-                 extend='neither')
+    im = ax1.pcolormesh(np.linspace(0, 10, 16).reshape((4, 4)), cmap=cmap)
+    values = np.linspace(0, 10, 5)
+
+    with rc_context({'axes.linewidth': 16}):
+        plt.colorbar(im, cax=ax2, cmap=cmap, orientation='horizontal',
+                     extend='both', extendfrac=0.5, values=values)
+        plt.colorbar(im, cax=ax3, cmap=cmap, orientation='horizontal',
+                     extend='both', values=values)
+        plt.colorbar(im, cax=ax4, cmap=cmap, orientation='horizontal',
+                     extend='both', extendrect=True, values=values)
+        plt.colorbar(im, cax=ax5, cmap=cmap, orientation='horizontal',
+                     extend='neither', values=values)
 
 
 if __name__ == '__main__':

src/_backend_agg.h

@@ -417,6 +417,7 @@ RendererAgg::_draw_path(path_t &path, bool has_clippath, const facepair_t &face,
             stroke.width(points_to_pixels(gc.linewidth));
             stroke.line_cap(gc.cap);
             stroke.line_join(gc.join);
+            stroke.miter_limit(points_to_pixels(gc.linewidth));
             theRasterizer.add_path(stroke);
         } else {
             dash_t dash(path);
@@ -425,6 +426,7 @@ RendererAgg::_draw_path(path_t &path, bool has_clippath, const facepair_t &face,
             stroke.line_cap(gc.cap);
             stroke.line_join(gc.join);
             stroke.width(linewidth);
+            stroke.miter_limit(points_to_pixels(gc.linewidth));
             theRasterizer.add_path(stroke);
         }
 
@@ -564,6 +566,7 @@ inline void RendererAgg::draw_markers(GCAgg &gc,
         stroke.width(points_to_pixels(gc.linewidth));
         stroke.line_cap(gc.cap);
         stroke.line_join(gc.join);
+        stroke.miter_limit(points_to_pixels(gc.linewidth));
         theRasterizer.reset();
         theRasterizer.add_path(stroke);
         agg::render_scanlines(theRasterizer, slineP8, scanlines);