Take hinting rcParam into account in MathTextParser cache.

We already check the state of the antialiasing rcParam in
MathTextParser._parse_cached; we just need to do the same with the
hinting rcParam (which is hidden behind backend_agg.get_hinting_flag,
but that just converts the rcParam to its freetype-specific
representation).

Author: anntzer

lib/matplotlib/mathtext.py

@@ -71,27 +71,27 @@ def parse(self, s, dpi=72, prop=None, *, antialiased=None):
         Depending on the *output* type, this returns either a `VectorParse` or
         a `RasterParse`.
         """
-        # lru_cache can't decorate parse() directly because prop
-        # is mutable; key the cache using an internal copy (see
-        # text._get_text_metrics_with_cache for a similar case).
+        # lru_cache can't decorate parse() directly because prop is
+        # mutable, so we key the cache using an internal copy (see
+        # Text._get_text_metrics_with_cache for a similar case); likewise,
+        # we need to check the mutable state of the text.antialiased and
+        # text.hinting rcParams.
         prop = prop.copy() if prop is not None else None
         antialiased = mpl._val_or_rc(antialiased, 'text.antialiased')
-        return self._parse_cached(s, dpi, prop, antialiased)
-
-    @functools.lru_cache(50)
-    def _parse_cached(self, s, dpi, prop, antialiased):
         from matplotlib.backends import backend_agg
+        load_glyph_flags = {
+            "vector": LOAD_NO_HINTING,
+            "raster": backend_agg.get_hinting_flag(),
+        }[self._output_type]
+        return self._parse_cached(s, dpi, prop, antialiased, load_glyph_flags)
 
+    @functools.lru_cache(50)
+    def _parse_cached(self, s, dpi, prop, antialiased, load_glyph_flags):
         if prop is None:
             prop = FontProperties()
         fontset_class = _api.check_getitem(
             self._font_type_mapping, fontset=prop.get_math_fontfamily())
-        load_glyph_flags = {
-            "vector": LOAD_NO_HINTING,
-            "raster": backend_agg.get_hinting_flag(),
-        }[self._output_type]
         fontset = fontset_class(prop, load_glyph_flags)
-
         fontsize = prop.get_size_in_points()
 
         if self._parser is None:  # Cache the parser globally.