matplotlib · jklymak · Jun 22, 2022 · Jun 14, 2022 · oscargus · Jun 14, 2022
diff --git a/doc/api/next_api_changes/behavior/23270-AL.rst b/doc/api/next_api_changes/behavior/23270-AL.rst
@@ -0,0 +1,5 @@
+The *math* parameter of ``mathtext.get_unicode_index`` is deprecated and defaults to False
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In math mode, ASCII hyphens (U+002D) are now replaced by unicode minus signs
+(U+2212) at the parsing stage.
diff --git a/doc/api/next_api_changes/deprecations/22507-AL.rst b/doc/api/next_api_changes/deprecations/22507-AL.rst
diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
@@ -34,7 +34,7 @@
 
 
 @_api.delete_parameter("3.6", "math")
-def get_unicode_index(symbol, math=True):  # Publicly exported.
+def get_unicode_index(symbol, math=False):  # Publicly exported.
     r"""
     Return the integer index (from the Unicode table) of *symbol*.
 
@@ -43,8 +43,8 @@ def get_unicode_index(symbol, math=True):  # Publicly exported.
     symbol : str
         A single (Unicode) character, a TeX command (e.g. r'\pi') or a Type1
         symbol name (e.g. 'phi').
-    math : bool, default: True
-        If False, always treat as a single Unicode character.
+    math : bool, default: False
+        If True (deprecated), replace ASCII hyphen-minus by Unicode minus.
     """
     # From UTF #25: U+2212 minus sign is the preferred
     # representation of the unary and binary minus sign rather than

diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_cm_00.svg b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_cm_00.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_dejavusans_00.svg b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_dejavusans_00.svg
diff --git a/lib/matplotlib/tests/test_mathtext.py b/lib/matplotlib/tests/test_mathtext.py
@@ -119,6 +119,7 @@
 # 'svgastext' tests switch svg output to embed text as text (rather than as
 # paths).
 svgastext_math_tests = [
+    r'$-$-',
 ]
 # 'lightweight' tests test only a single fontset (dejavusans, which is the
 # default) and only png outputs, in order to minimize the size of baseline
@@ -206,11 +207,10 @@ def test_mathtext_rendering(baseline_images, fontset, index, text):
 
 @pytest.mark.parametrize('index, text', enumerate(svgastext_math_tests),
                          ids=range(len(svgastext_math_tests)))
-@pytest.mark.parametrize(
-    'fontset', ['cm', 'stix', 'stixsans', 'dejavusans', 'dejavuserif'])
+@pytest.mark.parametrize('fontset', ['cm', 'dejavusans'])
 @pytest.mark.parametrize('baseline_images', ['mathtext0'], indirect=True)
 @image_comparison(
-    baseline_images=None,
+    baseline_images=None, extensions=['svg'],
     savefig_kwarg={'metadata': {  # Minimize image size.
         'Creator': None, 'Date': None, 'Format': None, 'Type': None}})
 def test_mathtext_rendering_svgastext(baseline_images, fontset, index, text):