Backport PR #21845: FIX: bbox subfigures

QuLogic · meeseeksmachine · commit 049a520d9981 · 2021-12-03T01:19:15.000Z
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1647,18 +1647,21 @@ def get_tightbbox(self, renderer, bbox_extra_artists=None):
               if (np.isfinite(b.width) and np.isfinite(b.height)
                   and (b.width != 0 or b.height != 0))]
 
+        isfigure = hasattr(self, 'bbox_inches')
         if len(bb) == 0:
-            if hasattr(self, 'bbox_inches'):
+            if isfigure:
                 return self.bbox_inches
             else:
                 # subfigures do not have bbox_inches, but do have a bbox
                 bb = [self.bbox]
 
         _bbox = Bbox.union(bb)
 
-        bbox_inches = TransformedBbox(_bbox, Affine2D().scale(1 / self.dpi))
+        if isfigure:
+            # transform from pixels to inches...
+            _bbox = TransformedBbox(_bbox, self.dpi_scale_trans.inverted())
 
-        return bbox_inches
+        return _bbox
 
     @staticmethod
     def _normalize_grid_string(layout):
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -1030,7 +1030,8 @@ def test_subfigure_tightbbox():
     sub = fig.subfigures(1, 2)
 
     np.testing.assert_allclose(
-            fig.get_tightbbox(fig.canvas.get_renderer()).width, 0.1)
+            fig.get_tightbbox(fig.canvas.get_renderer()).width,
+            8.0)
 
 
 @image_comparison(['test_subfigure_ss.png'], style='mpl20',
