Fix stackplot test.

mdboom · mdboom · commit f39c3af9129c · 2013-02-25T16:59:54.000-05:00
diff --git a/lib/matplotlib/axes.py b/lib/matplotlib/axes.py
@@ -1481,7 +1481,11 @@ def add_collection(self, collection, autolim=True):
 
         if collection.get_clip_path() is None:
             collection.set_clip_path(self.patch)
-        if autolim and collection._paths and len(collection._offsets):
+
+        if (autolim and
+            collection._paths is not None and
+            len(collection._paths) and
+            len(collection._offsets)):
             self.update_datalim(collection.get_datalim(self.transData))
 
         collection._remove_method = lambda h: self.collections.remove(h)
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
@@ -49,7 +49,7 @@ class Collection(artist.Artist, cm.ScalarMappable):
         * *cmap*: None (optional for
           :class:`matplotlib.cm.ScalarMappable`)
         * *hatch*: None
-        * *zorder*: 1 
+        * *zorder*: 1
 
 
     *offsets* and *transOffset* are used to translate the patch after
@@ -111,11 +111,9 @@ def __init__(self,
         self.set_hatch(hatch)
         self.set_offset_position(offset_position)
         self.set_zorder(zorder)
-        
+
         self._uniform_offsets = None
-        self._offsets = np.array([], np.float_)
-        # Force _offsets to be Nx2
-        self._offsets.shape = (0, 2)
+        self._offsets = np.array([[0, 0]], np.float_)
         if offsets is not None:
             offsets = np.asanyarray(offsets)
             offsets.shape = (-1, 2)             # Make it Nx2
