matplotlib
diff --git a/‎INSTALL
Copy file name to clipboardExpand all lines: INSTALL
+1-1Lines changed: 1 addition & 1 deletion b/‎INSTALL
Copy file name to clipboardExpand all lines: INSTALL
+1-1Lines changed: 1 addition & 1 deletion
diff --git a/‎lib/matplotlib/backend_bases.py
Copy file name to clipboardExpand all lines: lib/matplotlib/backend_bases.py
+8-6Lines changed: 8 additions & 6 deletions b/‎lib/matplotlib/backend_bases.py
Copy file name to clipboardExpand all lines: lib/matplotlib/backend_bases.py
+8-6Lines changed: 8 additions & 6 deletions
diff --git a/‎lib/mpl_toolkits/mplot3d/art3d.py
Copy file name to clipboardExpand all lines: lib/mpl_toolkits/mplot3d/art3d.py
+6-7Lines changed: 6 additions & 7 deletions b/‎lib/mpl_toolkits/mplot3d/art3d.py
Copy file name to clipboardExpand all lines: lib/mpl_toolkits/mplot3d/art3d.py
+6-7Lines changed: 6 additions & 7 deletions
diff --git a/‎setupext.py
Copy file name to clipboardExpand all lines: setupext.py
+3Lines changed: 3 additions & 0 deletions b/‎setupext.py
Copy file name to clipboardExpand all lines: setupext.py
+3Lines changed: 3 additions & 0 deletions
@@ -322,4 +322,4 @@ Framework with Visual Studio).  In addition to Visual Studio `CMake
 
 Since there is no canonical Windows package manager the build methods for
 freetype, zlib, libpng, tcl, & tk source code are documented as a build script
-at `matplotlib-winbuild <https://github.com/jbmohler/matplotlib-winbuild>`.
+at `matplotlib-winbuild <https://github.com/jbmohler/matplotlib-winbuild>`_.
@@ -98,19 +98,21 @@ def import_module(name):
 }
 
 
-def register_backend(format, backend, description):
+def register_backend(format, backend, description=None):
     """
     Register a backend for saving to a given file format.
 
-    *format*
+    format : str
         File extention
 
-    *backend*
-        Backend for handling file output (module string or canvas class)
+    backend : module string or canvas class
+        Backend for handling file output
 
-    *description*
-        Description of the file type
+    description : str, optional
+        Description of the file type.  Defaults to an empty string
     """
+    if description is None:
+        description = ''
     _default_backends[format] = backend
     _default_filetypes[format] = description
 
 
@@ -319,7 +319,7 @@ def __init__(self, *args, **kwargs):
         zs = kwargs.pop('zs', 0)
         zdir = kwargs.pop('zdir', 'z')
         self._depthshade = kwargs.pop('depthshade', True)
-        super(self.__class__, self).__init__(*args, **kwargs)
+        PatchCollection.__init__(self, *args, **kwargs)
         self.set_3d_properties(zs, zdir)
 
 
@@ -354,7 +354,7 @@ def do_3d_projection(self, renderer):
                self._edgecolor3d)
         ecs = mcolors.colorConverter.to_rgba_array(ecs, self._alpha)
         self.set_edgecolors(ecs)
-        super(self.__class__, self).set_offsets(list(zip(vxs, vys)))
+        PatchCollection.set_offsets(self, list(zip(vxs, vys)))
 
         if vzs.size > 0 :
             return min(vzs)
@@ -386,11 +386,10 @@ def __init__(self, *args, **kwargs):
         zs = kwargs.pop('zs', 0)
         zdir = kwargs.pop('zdir', 'z')
         self._depthshade = kwargs.pop('depthshade', True)
-        super(self.__class__, self).__init__(*args, **kwargs)
+        PathCollection.__init__(self, *args, **kwargs)
         self.set_3d_properties(zs, zdir)
 
-
-    def set_sort_zpos(self,val):
+    def set_sort_zpos(self, val):
         '''Set the position to use for z-sorting.'''
         self._sort_zpos = val
 
@@ -421,7 +420,7 @@ def do_3d_projection(self, renderer):
                self._edgecolor3d)
         ecs = mcolors.colorConverter.to_rgba_array(ecs, self._alpha)
         self.set_edgecolors(ecs)
-        super(self.__class__, self).set_offsets(list(zip(vxs, vys)))
+        PathCollection.set_offsets(self, list(zip(vxs, vys)))
 
         if vzs.size > 0 :
             return min(vzs)
@@ -441,7 +440,7 @@ def patch_collection_2d_to_3d(col, zs=0, zdir='z', depthshade=True):
                     collection along the *zdir* axis. Defaults to 0.
     *zdir*          The axis in which to place the patches. Default is "z".
     *depthshade*    Whether to shade the patches to give a sense of depth.
-                    Defaults to *True*. 
+                    Defaults to *True*.
 
     """
     if isinstance(col, PathCollection):
 
@@ -1003,6 +1003,9 @@ class Png(SetupPackage):
     name = "png"
 
     def check(self):
+        if sys.platform == 'win32':
+            return "Unknown version"
+
         status, output = getstatusoutput("libpng-config --version")
         if status == 0:
             version = output