Convert path to str in FontManager.addpath

Author: oscargus

lib/matplotlib/font_manager.py

@@ -1091,6 +1091,8 @@ def addfont(self, path):
         ----------
         path : str or path-like
         """
+        path = str(path)  # Convert to string in case of a path as
+                          # afmFontProperty and FT2Font expect this
         if Path(path).suffix.lower() == ".afm":
             with open(path, "rb") as fh:
                 font = _afm.AFM(fh)

lib/matplotlib/tests/test_font_manager.py

@@ -176,6 +176,13 @@ def test_user_fonts_linux(tmpdir, monkeypatch):
     _get_fontconfig_fonts.cache_clear()
 
 
+def test_addfont():
+    font_test_file = 'mpltest.ttf'
+    path = Path(__file__).parent / font_test_file
+    # Add font using Path, which should not produce an error. See #22582
+    fontManager.addfont(path)
+
+
 @pytest.mark.skipif(sys.platform != 'win32', reason='Windows only')
 def test_user_fonts_win32():
     if not (os.environ.get('APPVEYOR') or os.environ.get('TF_BUILD')):