Merge 'v1.4.x' into master

Conflicts:
	lib/matplotlib/__init__.py
	lib/matplotlib/tests/test_legend.py

__init__:

  conflicts in white-listing tests on both branches

test_legend:

  conflicts from adding new tests on both branches

Author: tacaswell

lib/matplotlib/__init__.py

@@ -1395,7 +1395,6 @@ def tk_window_focus():
     'matplotlib.tests.test_arrow_patches',
     'matplotlib.tests.test_artist',
     'matplotlib.tests.test_axes',
-    'matplotlib.tests.test_axes_grid1',
     'matplotlib.tests.test_backend_bases',
     'matplotlib.tests.test_backend_pdf',
     'matplotlib.tests.test_backend_pgf',
@@ -1440,8 +1439,9 @@ def tk_window_focus():
     'matplotlib.tests.test_tightlayout',
     'matplotlib.tests.test_transforms',
     'matplotlib.tests.test_triangulation',
-    'mpl_toolkits.tests.test_mplot3d',
     'matplotlib.tests.test_widgets',
+    'mpl_toolkits.tests.test_mplot3d',
+    'mpl_toolkits.tests.test_axes_grid1',
     ]
 
 

lib/matplotlib/rcsetup.py

@@ -108,6 +108,16 @@ def validate_float(s):
         raise ValueError('Could not convert "%s" to float' % s)
 
 
+def validate_float_or_None(s):
+    """convert s to float or raise"""
+    if s is None:
+        return None
+    try:
+        return float(s)
+    except ValueError:
+        raise ValueError('Could not convert "%s" to float' % s)
+
+
 def validate_int(s):
     """convert s to int or raise"""
     try:
@@ -644,7 +654,7 @@ def __call__(self, s):
      # whether or not to draw a frame around legend
     'legend.frameon': [True, validate_bool],
      # alpha value of the legend frame
-    'legend.framealpha': [1.0, validate_float],
+    'legend.framealpha': [None, validate_float_or_None],
 
     ## the following dimensions are in fraction of the font size
     'legend.borderpad': [0.4, validate_float],  # units are fontsize

lib/matplotlib/tests/baseline_images/test_legend/rcparam_alpha.png

@@ -76,6 +76,33 @@ def test_labels_first():
     ax.legend(loc=0, markerfirst=False)
 
 
+@image_comparison(baseline_images=['rgba_alpha'],
+                  extensions=['png'], remove_text=True)
+def test_alpha_rgba():
+    import matplotlib.pyplot as plt
+
+    fig, ax = plt.subplots(1, 1)
+    ax.plot(range(10), lw=5)
+    leg = plt.legend(['Longlabel that will go away'], loc=10)
+    leg.legendPatch.set_facecolor([1, 0, 0, 0.5])
+
+
+@image_comparison(baseline_images=['rcparam_alpha'],
+                  extensions=['png'], remove_text=True)
+def test_alpha_rcparam():
+    import matplotlib.pyplot as plt
+
+    fig, ax = plt.subplots(1, 1)
+    ax.plot(range(10), lw=5)
+    with mpl.rc_context(rc={'legend.framealpha': .75}):
+        leg = plt.legend(['Longlabel that will go away'], loc=10)
+        # this alpha is going to be over-ridden by the rcparam whith
+        # sets the alpha of the patch to be non-None which causes the alpha
+        # value of the face color to be discarded.  This behavior may not be
+        # ideal, but it is what it is and we should keep track of it changing
+        leg.legendPatch.set_facecolor([1, 0, 0, 0.5])
+
+
 @image_comparison(baseline_images=['fancy'], remove_text=True)
 def test_fancy():
     # using subplot triggers some offsetbox functionality untested elsewhere

lib/matplotlib/tests/baseline_images/test_legend/rgba_alpha.png

@@ -321,7 +321,7 @@ backend      : %(backend)s
 #legend.columnspacing : 2.    # the border between the axes and legend edge in fraction of fontsize
 #legend.shadow        : False
 #legend.frameon       : True   # whether or not to draw a frame around legend
-#legend.framealpha    : 1.0    # opacity of of legend frame
+#legend.framealpha    : None    # opacity of of legend frame
 #legend.scatterpoints : 3 # number of scatter points
 #legend.facecolor     : None   # legend background color (when None inherits from axes.facecolor)
 #legend.edgecolor     : None   # legend edge color (when None inherits from axes.facecolor)