Fix autoscaling with axhspan (#28487)

QuLogic · web-flow · commit f5067c16757f · 2024-06-29T12:52:32.000-06:00
This only triggers when the normal (without an `axhspan` call)
autolimits are far from 0, so modify a test to match that.
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
@@ -8250,10 +8250,10 @@ 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():
