Fix a crash when saving to PDF or SVG with contour hatching.

Author: mdboom

lib/matplotlib/backends/backend_pdf.py

@@ -1057,6 +1057,9 @@ def alphaState(self, alpha):
         return name
 
     def hatchPattern(self, hatch_style):
+        # The colors may come in as numpy arrays, which aren't hashable
+        hatch_style = (tuple(hatch_style[0]), tuple(hatch_style[1]), hatch_style[2])
+
         pattern = self.hatchPatterns.get(hatch_style, None)
         if pattern is not None:
             return pattern

lib/matplotlib/backends/backend_svg.py

@@ -327,7 +327,7 @@ def _get_hatch(self, gc, rgbFace):
         """
         Create a new hatch pattern
         """
-        dictkey = (gc.get_hatch(), rgbFace, gc.get_rgb())
+        dictkey = (gc.get_hatch(), tuple(rgbFace), tuple(gc.get_rgb()))
         oid = self._hatchd.get(dictkey)
         if oid is None:
             oid = self._make_id(u'h', dictkey)

lib/matplotlib/tests/baseline_images/test_axes/contour_hatching.pdf

@@ -660,6 +660,21 @@ def test_hist_log():
     ax.set_xticks([])
     ax.set_yticks([])
 
+@image_comparison(baseline_images=['contour_hatching'])
+def test_contour_hatching():
+    x = np.linspace(-3, 5, 150).reshape(1, -1)
+    y = np.linspace(-3, 5, 120).reshape(-1, 1)
+    z = np.cos(x) + np.sin(y)
+
+    # we no longer need x and y to be 2 dimensional, so flatten them.
+    x, y = x.flatten(), y.flatten()
+
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    cs = ax.contourf(x, y, z, hatches=['-', '/', '\\', '//'],
+                      cmap=plt.get_cmap('gray'),
+                      extend='both', alpha=0.5)
+
 if __name__=='__main__':
     import nose
     nose.runmodule(argv=['-s','--with-doctest'], exit=False)