Fix warning when legend is added while using TeX.

Struan-Murray · anntzer · QuLogic · commit 5037eef19149 · 2020-08-27T00:59:51.000-04:00
Fixes #17518. Co-authored-by: Antony Lee <anntzer.lee@gmail.com>
diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
@@ -881,7 +881,8 @@ def get_window_extent(self, renderer):
 
     def get_extent(self, renderer):
         _, h_, d_ = renderer.get_text_width_height_descent(
-            "lp", self._text._fontproperties, ismath=False)
+            "lp", self._text._fontproperties,
+            ismath="TeX" if self._text.get_usetex() else False)
 
         bbox, info, d = self._text._get_layout(renderer)
         w, h = bbox.width, bbox.height
