Fix Text class bug when font argument is provided without math_fontfamily (matplotlib#20101)

* fix mathtext.fontset issue

* fix argument order issue

* better fix using alias_map

* indent fix

* Update lib/matplotlib/text.py

indent fix

Co-authored-by: Elliott Sales de Andrade <[email protected]>

* add test

* split into 2 test methods

* fix test

* add a whitespace

* use cbook.normalize_kwargs

* no need to copy (normalize_kwargs already copy it)

Co-authored-by: Elliott Sales de Andrade <[email protected]>

Author: ain-soph

lib/matplotlib/font_manager.py

@@ -666,7 +666,7 @@ def __init__(self, family=None, style=None, variant=None, weight=None,
         self._stretch = rcParams['font.stretch']
         self._size = rcParams['font.size']
         self._file = None
-        self._math_fontfamily = None
+        self.set_math_fontfamily(math_fontfamily)
 
         if isinstance(family, str):
             # Treat family as a fontconfig pattern if it is the only
@@ -683,7 +683,6 @@ def __init__(self, family=None, style=None, variant=None, weight=None,
         self.set_stretch(stretch)
         self.set_file(fname)
         self.set_size(size)
-        self.set_math_fontfamily(math_fontfamily)
 
     @classmethod
     def _from_any(cls, arg):

lib/matplotlib/tests/test_mathtext.py

@@ -390,6 +390,46 @@ def test_math_fontfamily():
              size=24, math_fontfamily='stix')
 
 
+def test_default_math_fontfamily():
+    mpl.rcParams['mathtext.fontset'] = 'cm'
+    test_str = r'abc$abc\alpha$'
+    fig, ax = plt.subplots()
+
+    text1 = fig.text(0.1, 0.1, test_str, font='Arial')
+    prop1 = text1.get_fontproperties()
+    assert prop1.get_math_fontfamily() == 'cm'
+    text2 = fig.text(0.2, 0.2, test_str, fontproperties='Arial')
+    prop2 = text2.get_fontproperties()
+    assert prop2.get_math_fontfamily() == 'cm'
+
+    fig.draw_no_output()
+
+
+def test_argument_order():
+    mpl.rcParams['mathtext.fontset'] = 'cm'
+    test_str = r'abc$abc\alpha$'
+    fig, ax = plt.subplots()
+
+    text1 = fig.text(0.1, 0.1, test_str,
+                     math_fontfamily='dejavusans', font='Arial')
+    prop1 = text1.get_fontproperties()
+    assert prop1.get_math_fontfamily() == 'dejavusans'
+    text2 = fig.text(0.2, 0.2, test_str,
+                     math_fontfamily='dejavusans', fontproperties='Arial')
+    prop2 = text2.get_fontproperties()
+    assert prop2.get_math_fontfamily() == 'dejavusans'
+    text3 = fig.text(0.3, 0.3, test_str,
+                     font='Arial', math_fontfamily='dejavusans')
+    prop3 = text3.get_fontproperties()
+    assert prop3.get_math_fontfamily() == 'dejavusans'
+    text4 = fig.text(0.4, 0.4, test_str,
+                     fontproperties='Arial', math_fontfamily='dejavusans')
+    prop4 = text4.get_fontproperties()
+    assert prop4.get_math_fontfamily() == 'dejavusans'
+
+    fig.draw_no_output()
+
+
 def test_mathtext_cmr10_minus_sign():
     # cmr10 does not contain a minus sign and used to issue a warning
     # RuntimeWarning: Glyph 8722 missing from current font.

lib/matplotlib/text.py

@@ -158,8 +158,7 @@ def __init__(self,
 
     def update(self, kwargs):
         # docstring inherited
-        # make a copy so we do not mutate user input!
-        kwargs = dict(kwargs)
+        kwargs = cbook.normalize_kwargs(kwargs, Text)
         sentinel = object()  # bbox can be None, so use another sentinel.
         # Update fontproperties first, as it has lowest priority.
         fontproperties = kwargs.pop("fontproperties", sentinel)