Backport PR matplotlib#31628: FIX: use axis lines tight bbox within axis artist tight bbox

Author: QuLogic

lib/mpl_toolkits/axisartist/axis_artist.py

@@ -1086,7 +1086,7 @@ def get_tightbbox(self, renderer=None):
             *self.minor_ticklabels.get_window_extents(renderer),
             self.label.get_window_extent(renderer),
             self.offsetText.get_window_extent(renderer),
-            self.line.get_window_extent(renderer),
+            self.line.get_tightbbox(renderer),
         ]
         bb = [b for b in bb if b and (b.width != 0 or b.height != 0)]
         if bb:

lib/mpl_toolkits/axisartist/tests/test_axis_artist.py

@@ -1,7 +1,13 @@
+import numpy as np
+
+import matplotlib as mpl
 import matplotlib.pyplot as plt
+from matplotlib.projections import PolarAxes
 from matplotlib.testing.decorators import image_comparison
+from matplotlib.transforms import Affine2D
 
-from mpl_toolkits.axisartist import AxisArtistHelperRectlinear
+from mpl_toolkits.axisartist import (AxisArtistHelperRectlinear, GridHelperCurveLinear,
+                                     HostAxes)
 from mpl_toolkits.axisartist.axis_artist import (AxisArtist, AxisLabel,
                                                  LabelBase, Ticks, TickLabels)
 
@@ -90,3 +96,24 @@ def test_axis_artist():
     axisline.label.set_pad(5)
 
     ax.set_ylabel("Test")
+
+
+@mpl.style.context('default')
+def test_axisartist_tightbbox():
+    fig = plt.figure()
+    tr = Affine2D().scale(np.pi / 180., 1.) + PolarAxes.PolarTransform()
+    grid_helper = GridHelperCurveLinear(tr)
+    ax = fig.add_subplot(axes_class=HostAxes, grid_helper=grid_helper)
+    ax.axis["lon"] = ax.new_floating_axis(1, 9)
+
+    ax.set_xlim(-5, 12)
+    ax.set_ylim(-5, 10)
+
+    ax.axis['lon'].major_ticklabels.set_visible(False)
+
+    # Since the labels are invisible and the lines are clipped to the axes,
+    # the axis's tight bbox should be contained in the axes box.
+    renderer = fig._get_renderer()
+    tight_points = ax.axis['lon'].get_tightbbox(renderer).get_points()
+    for point in tight_points:
+        assert ax.bbox.contains(*point)