Don't clear a new Axis when registering with a Spine.

QuLogic · QuLogic · commit 799946c99f4f · 2017-05-15T20:11:05.000-04:00
If the Axis was just created, calling Axis.cla is redundant because it
just happened.
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -607,11 +607,11 @@ def get_window_extent(self, *args, **kwargs):
     def _init_axis(self):
         "move this out of __init__ because non-separable axes don't use it"
         self.xaxis = maxis.XAxis(self)
-        self.spines['bottom'].register_axis(self.xaxis)
-        self.spines['top'].register_axis(self.xaxis)
+        self.spines['bottom'].register_axis(self.xaxis, _init=True)
+        self.spines['top'].register_axis(self.xaxis, _init=True)
         self.yaxis = maxis.YAxis(self)
-        self.spines['left'].register_axis(self.yaxis)
-        self.spines['right'].register_axis(self.yaxis)
+        self.spines['left'].register_axis(self.yaxis, _init=True)
+        self.spines['right'].register_axis(self.yaxis, _init=True)
         self._update_transScale()
 
     def set_figure(self, fig):
diff --git a/lib/matplotlib/spines.py b/lib/matplotlib/spines.py
@@ -151,15 +151,17 @@ def _ensure_position_is_set(self):
             self._position = ('outward', 0.0)  # in points
             self.set_position(self._position)
 
-    def register_axis(self, axis):
+    def register_axis(self, axis, _init=False):
         """register an axis
 
         An axis should be registered with its corresponding spine from
         the Axes instance. This allows the spine to clear any axis
         properties when needed.
         """
         self.axis = axis
-        if self.axis is not None:
+        if not _init and self.axis is not None:
+            # Clear the axis when added, but *not* if the caller says it was
+            # just created.
             self.axis.cla()
         self.stale = True
 
