Do not clear Axis when registering spine

oscargus · oscargus · commit 8107d05fcb4f · 2023-06-21T20:02:22.000+02:00
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -814,10 +814,10 @@ def get_window_extent(self, renderer=None):
 
     def _init_axis(self):
         # This is moved out of __init__ because non-separable axes don't use it
-        self.xaxis = maxis.XAxis(self)
+        self.xaxis = maxis.XAxis(self, clear=False)
         self.spines.bottom.register_axis(self.xaxis)
         self.spines.top.register_axis(self.xaxis)
-        self.yaxis = maxis.YAxis(self)
+        self.yaxis = maxis.YAxis(self, clear=False)
         self.spines.left.register_axis(self.yaxis)
         self.spines.right.register_axis(self.yaxis)
 
@@ -1272,8 +1272,7 @@ def __clear(self):
         xaxis_visible = self.xaxis.get_visible()
         yaxis_visible = self.yaxis.get_visible()
 
-        for axis in self._axis_map.values():
-            axis.clear()  # Also resets the scale to linear.
+        # Clearing the spines also clears the axis, which resets the scale to linear
         for spine in self.spines.values():
             spine.clear()
 
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -632,7 +632,7 @@ def __str__(self):
         return "{}({},{})".format(
             type(self).__name__, *self.axes.transAxes.transform((0, 0)))
 
-    def __init__(self, axes, *, pickradius=15):
+    def __init__(self, axes, *, pickradius=15, clear=True):
         """
         Parameters
         ----------
@@ -641,6 +641,8 @@ def __init__(self, axes, *, pickradius=15):
         pickradius : float
             The acceptance radius for containment tests. See also
             `.Axis.contains`.
+        clear : bool, default: True
+            Whether to clear the Axis on creation.
         """
         super().__init__()
         self._remove_overlapping_locs = True
@@ -674,7 +676,8 @@ def __init__(self, axes, *, pickradius=15):
         self._major_tick_kw = dict()
         self._minor_tick_kw = dict()
 
-        self.clear()
+        if clear:
+            self.clear()
         self._autoscale_on = True
 
     @property
diff --git a/lib/matplotlib/axis.pyi b/lib/matplotlib/axis.pyi
@@ -105,7 +105,8 @@ class Axis(martist.Artist):
     offsetText: Text
     labelpad: float
     pickradius: float
-    def __init__(self, axes, *, pickradius: float = ...) -> None: ...
+    def __init__(self, axes, *, pickradius: float = ...,
+                 clear: bool = ...) -> None: ...
     @property
     def isDefault_majloc(self) -> bool: ...
     @isDefault_majloc.setter
diff --git a/lib/matplotlib/spines.py b/lib/matplotlib/spines.py
@@ -214,8 +214,6 @@ def register_axis(self, axis):
         properties when needed.
         """
         self.axis = axis
-        if self.axis is not None:
-            self.axis.clear()
         self.stale = True
 
     def clear(self):
