Backport PR #28487: Fix autoscaling with axhspan

QuLogic · meeseeksmachine · commit 475d5b70daa5 · 2024-06-29T18:52:37.000Z
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -1028,7 +1028,7 @@ def axhspan(self, ymin, ymax, xmin=0, xmax=1, **kwargs):
         # For Rectangles and non-separable transforms, add_patch can be buggy
         # and update the x limits even though it shouldn't do so for an
         # yaxis_transformed patch, so undo that update.
-        ix = self.dataLim.intervalx
+        ix = self.dataLim.intervalx.copy()
         mx = self.dataLim.minposx
         self.add_patch(p)
         self.dataLim.intervalx = ix
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -8195,10 +8195,10 @@ def test_relative_ticklabel_sizes(size):
 def test_multiplot_autoscale():
     fig = plt.figure()
     ax1, ax2 = fig.subplots(2, 1, sharex='all')
-    ax1.scatter([1, 2, 3, 4], [2, 3, 2, 3])
+    ax1.plot([18000, 18250, 18500, 18750], [2, 3, 2, 3])
     ax2.axhspan(-5, 5)
     xlim = ax1.get_xlim()
-    assert np.allclose(xlim, [0.5, 4.5])
+    assert np.allclose(xlim, [18000, 18800])
 
 
 def test_sharing_does_not_link_positions():
