Merge pull request matplotlib#28479 from rcomer/v3.9.x

QuLogic · web-flow · commit 24e30133b6e2 · 2024-06-27T15:19:06.000-04:00
Backport PR matplotlib#28397 (FIX: stale root Figure when adding/updating subfigures)
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1633,6 +1633,8 @@ def add_subfigure(self, subplotspec, **kwargs):
         sf = SubFigure(self, subplotspec, **kwargs)
         self.subfigs += [sf]
         sf._remove_method = self.subfigs.remove
+        sf.stale_callback = _stale_figure_callback
+        self.stale = True
         return sf
 
     def sca(self, a):
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -1733,3 +1733,27 @@ def test_warn_colorbar_mismatch():
     subfig3_1.colorbar(im3_2)   # should not warn
     with pytest.warns(UserWarning, match="different Figure"):
         subfig3_1.colorbar(im4_1)
+
+
+def test_subfigure_stale_propagation():
+    fig = plt.figure()
+
+    fig.draw_without_rendering()
+    assert not fig.stale
+
+    sfig1 = fig.subfigures()
+    assert fig.stale
+
+    fig.draw_without_rendering()
+    assert not fig.stale
+    assert not sfig1.stale
+
+    sfig2 = sfig1.subfigures()
+    assert fig.stale
+
+    fig.draw_without_rendering()
+    assert not fig.stale
+    assert not sfig2.stale
+
+    sfig2.stale = True
+    assert fig.stale
