FIX: adjust_bbox should not modify layout engine

Author: rcomer

lib/matplotlib/_tight_bbox.py

@@ -17,8 +17,6 @@ def adjust_bbox(fig, bbox_inches, fixed_dpi=None):
     """
     origBbox = fig.bbox
     origBboxInches = fig.bbox_inches
-    orig_layout = fig.get_layout_engine()
-    fig.set_layout_engine(None)
     _boxout = fig.transFigure._boxout
 
     old_aspect = []
@@ -46,7 +44,6 @@ def restore_bbox():
 
         fig.bbox = origBbox
         fig.bbox_inches = origBboxInches
-        fig.set_layout_engine(orig_layout)
         fig.transFigure._boxout = _boxout
         fig.transFigure.invalidate()
         fig.patch.set_bounds(0, 0, 1, 1)

lib/matplotlib/tests/test_figure.py

@@ -532,6 +532,13 @@ def test_savefig_pixel_ratio(backend):
     assert ratio1 == ratio2
 
 
+def test_savefig_preserve_layout_engine(tmp_path):
+    fig = plt.figure(layout='compressed')
+    fig.savefig(tmp_path / 'foo.png', bbox_inches='tight')
+
+    assert fig.get_layout_engine()._compress
+
+
 def test_figure_repr():
     fig = plt.figure(figsize=(10, 20), dpi=10)
     assert repr(fig) == "<Figure size 100x200 with 0 Axes>"