Subfigures become stale when their artists are stale

Author: rcomer

lib/matplotlib/figure.py

@@ -64,8 +64,8 @@
 
 
 def _stale_figure_callback(self, val):
-    if self.figure:
-        self.figure.stale = val
+    if (fig := self.get_figure(root=False)) is not None:
+        fig.stale = val
 
 
 class _AxesStack:

lib/matplotlib/tests/test_figure.py

@@ -1774,10 +1774,13 @@ def test_subfigure_stale_propagation():
 
     sfig2 = sfig1.subfigures()
     assert fig.stale
+    assert sfig1.stale
 
     fig.draw_without_rendering()
     assert not fig.stale
+    assert not sfig1.stale
     assert not sfig2.stale
 
     sfig2.stale = True
+    assert sfig1.stale
     assert fig.stale