From 997b69ea46f1acfbc94d33a17725753e16fea02a Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Mon, 4 Oct 2021 22:41:18 +0200
Subject: [PATCH] Clear findfont cache when calling addfont().

... as new fonts may invalidate previous searches (e.g. a previous
findfont may have chosen to return an approximate match, whereas the
newly added font is an exact match).

No test, as there is no machinery to *remove* a font from FontManager
yet so we add a font just temporarily within the test.
---
 lib/matplotlib/font_manager.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
index 9d45575eb13d..9716e72b5330 100644
--- a/lib/matplotlib/font_manager.py
+++ b/lib/matplotlib/font_manager.py
@@ -1092,6 +1092,7 @@ def addfont(self, path):
             font = ft2font.FT2Font(path)
             prop = ttfFontProperty(font)
             self.ttflist.append(prop)
+        self._findfont_cached.cache_clear()
 
     @property
     def defaultFont(self):