Merge remote-tracking branch 'upstream/v1.2.x' into v1.3.x

mdboom · mdboom · commit e4ec9d596a20 · 2013-09-27T09:16:30.000-04:00
Conflicts:
	lib/matplotlib/tests/test_colors.py
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -901,10 +901,10 @@ def __call__(self, value, clip=None):
 
         self.autoscale_None(result)
         vmin, vmax = self.vmin, self.vmax
-        if vmin > vmax:
-            raise ValueError("minvalue must be less than or equal to maxvalue")
-        elif vmin == vmax:
+        if vmin == vmax:
             result.fill(0)   # Or should it be all masked?  Or 0.5?
+        elif vmin > vmax:
+            raise ValueError("minvalue must be less than or equal to maxvalue")
         else:
             vmin = float(vmin)
             vmax = float(vmax)
@@ -942,9 +942,9 @@ def autoscale(self, A):
 
     def autoscale_None(self, A):
         ' autoscale only None-valued vmin or vmax'
-        if self.vmin is None:
+        if self.vmin is None and np.size(A) > 0:
             self.vmin = ma.min(A)
-        if self.vmax is None:
+        if self.vmax is None and np.size(A) > 0:
             self.vmax = ma.max(A)
 
     def scaled(self):
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -7,7 +7,7 @@
 import matplotlib.colors as mcolors
 import matplotlib.cm as cm
 import matplotlib.pyplot as plt
-from matplotlib.testing.decorators import image_comparison
+from matplotlib.testing.decorators import image_comparison, cleanup
 
 
 def test_colormap_endian():
@@ -175,6 +175,14 @@ def test_cmap_and_norm_from_levels_and_colors2():
     assert_raises(ValueError, mcolors.from_levels_and_colors, levels, colors)
 
 
+@cleanup
+def test_autoscale_masked():
+    # Test for #2336. Previously fully masked data would trigger a ValueError.
+    data = np.ma.masked_all((12, 20))
+    plt.pcolor(data)
+    plt.draw()
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=['-s', '--with-doctest'], exit=False)
