matplotlib · anntzer · Dec 31, 2020 · Jan 5, 2021 · Jan 5, 2021
diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
@@ -2158,7 +2158,8 @@ def __init__(self):
 
         p.sqrt <<= Group(
             Suppress(Literal(r"\sqrt"))
-            - ((Optional(p.lbracket + p.int_literal + p.rbracket, default=None)
+            - ((Group(Optional(
+                p.lbracket + OneOrMore(~p.rbracket + p.token) + p.rbracket))
                 + p.required_group)
                | Error("Expected \\sqrt{value}"))
         )
@@ -2864,10 +2865,10 @@ def sqrt(self, s, loc, toks):
 
         # Add the root and shift it upward so it is above the tick.
         # The value of 0.6 is a hard-coded hack ;)
-        if root is None:
+        if not root:
             root = Box(check.width * 0.5, 0., 0.)
         else:
-            root = Hlist([Char(x, state) for x in root])
+            root = Hlist(root)
             root.shrink()
             root.shrink()
 

diff --git a/lib/matplotlib/backends/backend_svg.py b/lib/matplotlib/backends/backend_svg.py
@@ -21,7 +21,7 @@
 from matplotlib.backends.backend_mixed import MixedModeRenderer
 from matplotlib.colors import rgb2hex
 from matplotlib.dates import UTC
-from matplotlib.font_manager import findfont, get_font
+from matplotlib.font_manager import findfont, get_font, ttfFontProperty
 from matplotlib.ft2font import LOAD_NO_HINTING
 from matplotlib.mathtext import MathTextParser
 from matplotlib.path import Path
@@ -94,6 +94,12 @@ def escape_attrib(s):
     return s
 
 
+def _quote_escape_attrib(s):
+    return ('"' + escape_cdata(s) + '"' if '"' not in s else
+            "'" + escape_cdata(s) + "'" if "'" not in s else
+            '"' + escape_attrib(s) + '"')
+
+
 def short_float_fmt(x):
     """
     Create a short string representation of a float, which is %f
@@ -159,8 +165,8 @@ def start(self, tag, attrib={}, **extra):
         for k, v in sorted({**attrib, **extra}.items()):
             if v:
                 k = escape_cdata(k)
-                v = escape_attrib(v)
-                self.__write(' %s="%s"' % (k, v))
+                v = _quote_escape_attrib(v)
+                self.__write(' %s=%s' % (k, v))
         self.__open = 1
         return len(self.__tags) - 1
 
@@ -1197,11 +1203,21 @@ def _draw_text_as_text(self, gc, x, y, s, prop, angle, ismath, mtext=None):
             # Sort the characters by font, and output one tspan for each.
             spans = OrderedDict()
             for font, fontsize, thetext, new_x, new_y in glyphs:
-                style = generate_css({
-                    'font-size': short_float_fmt(fontsize) + 'px',
-                    'font-family': font.family_name,
-                    'font-style': font.style_name.lower(),
-                    'font-weight': font.style_name.lower()})
+                entry = ttfFontProperty(font)
+                font_parts = ['font:']
+                if entry.style != 'normal':
+                    font_parts.append(entry.style)
+                if entry.variant != 'normal':
+                    font_parts.append(entry.variant)
+                if entry.weight != 400:
+                    font_parts.append(f'{entry.weight}')
+                font_parts.extend([
+                    f'{short_float_fmt(fontsize)}px',
+                    f'{entry.name!r}',  # ensure quoting
+                ])
+                if entry.stretch != 'normal':
+                    font_parts.extend(['; font-stretch:', entry.stretch])
+                style = ' '.join(font_parts)
                 if thetext == 32:
                     thetext = 0xa0  # non-breaking space
                 spans.setdefault(style, []).append((new_x, -new_y, thetext))

diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -181,7 +181,7 @@ def __call__(self, orig, dest):
                 # just be reported as a regular exception below).
                 "DISPLAY": "",
                 # Do not load any user options.
-                "INKSCAPE_PROFILE_DIR": os.devnull,
+                "INKSCAPE_PROFILE_DIR": self._tmpdir.name,
             }
             # Old versions of Inkscape (e.g. 0.48.3.1) seem to sometimes
             # deadlock when stderr is redirected to a pipe, so we redirect it
@@ -233,6 +233,15 @@ def __del__(self):
             self._tmpdir.cleanup()
 
 
+class _SVGWithMatplotlibFontsConverter(_SVGConverter):
+    def __call__(self, orig, dest):
+        if not hasattr(self, "_tmpdir"):
+            self._tmpdir = TemporaryDirectory()
+            shutil.copytree(cbook._get_data_path("fonts/ttf"),
+                            Path(self._tmpdir.name, "fonts"))
+        return super().__call__(orig, dest)
+
+
 def _update_converter():
     try:
         mpl._get_executable_info("gs")
@@ -254,6 +263,7 @@ def _update_converter():
 #: extension to png format.
 converter = {}
 _update_converter()
+_svg_with_matplotlib_fonts_converter = _SVGWithMatplotlibFontsConverter()
 
 
 def comparable_formats():
@@ -303,7 +313,12 @@ def convert(filename, cache):
                 return str(newpath)
 
         _log.debug("For %s: converting to png.", filename)
-        converter[path.suffix[1:]](path, newpath)
+        convert = converter[path.suffix[1:]]
+        if path.suffix == ".svg":
+            contents = path.read_text()
+            if 'style="font:' in contents:  # for svg.fonttype = none.
+                convert = _svg_with_matplotlib_fonts_converter
+        convert(path, newpath)
 
         if cache_dir is not None:
             _log.debug("For %s: caching conversion result.", filename)

diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext1_all_00.svg b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext1_all_00.svg
diff --git a/lib/matplotlib/tests/test_mathtext.py b/lib/matplotlib/tests/test_mathtext.py
@@ -1,6 +1,8 @@
 import io
-import os
+from pathlib import Path
 import re
+import shlex
+from xml.etree import ElementTree as ET
 
 import numpy as np
 import pytest
@@ -110,6 +112,9 @@
     r'$\left(X\right)_{a}^{b}$',  # github issue 7615
     r'$\dfrac{\$100.00}{y}$',  # github issue #1888
 ]
+svg_only_math_tests = [
+    r'$\sqrt[ab]{123}$',  # github issue #8665
+]
 
 digits = "0123456789"
 uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -165,8 +170,6 @@
         for set in chars:
             font_tests.append(wrapper % set)
 
-font_tests = list(filter(lambda x: x[1] is not None, enumerate(font_tests)))
-
 
 @pytest.fixture
 def baseline_images(request, fontset, index):
@@ -190,6 +193,32 @@ def test_mathtext_rendering(baseline_images, fontset, index, test):
              horizontalalignment='center', verticalalignment='center')
 
 
+cur_svg_only_math_tests = list(
+    filter(lambda x: x[1] is not None, enumerate(svg_only_math_tests)))
+
+
+@pytest.mark.parametrize('index, test', cur_svg_only_math_tests,
+                         ids=[str(idx) for idx, _ in cur_svg_only_math_tests])
+@pytest.mark.parametrize('fontset', ['all'])
+@pytest.mark.parametrize('baseline_images', ['mathtext1'], indirect=True)
+@image_comparison(
+    baseline_images=None, extensions=['svg'],
+    savefig_kwarg={
+        'metadata': {  # Minimize svg size.
+            'Creator': None, 'Date': None, 'Format': None, 'Type': None}})
+def test_mathtext_rendering_svg_only(baseline_images, fontset, index, test):
+    mpl.rcParams['svg.fonttype'] = 'none'
+    fig = plt.figure(figsize=(5.25, 5.25))
+    fig.patch.set_visible(False)  # Minimize svg size.
+    fontsets = ['cm', 'stix', 'stixsans', 'dejavusans', 'dejavuserif']
+    for i, fontset in enumerate(fontsets):
+        fig.text(0.5, (i + .5) / len(fontsets), test, math_fontfamily=fontset,
+                 horizontalalignment='center', verticalalignment='center')
+
+
+font_tests = list(filter(lambda x: x[1] is not None, enumerate(font_tests)))
+
+
 @pytest.mark.parametrize('index, test', font_tests,
                          ids=[str(index) for index, _ in font_tests])
 @pytest.mark.parametrize('fontset',
@@ -328,7 +357,7 @@ def test_mathtext_fallback_to_cm_invalid():
      ("stix", ['DejaVu Sans', 'mpltest', 'STIXGeneral'])])
 def test_mathtext_fallback(fallback, fontlist):
     mpl.font_manager.fontManager.addfont(
-        os.path.join((os.path.dirname(os.path.realpath(__file__))), 'mpltest.ttf'))
+        str(Path(__file__).resolve().parent / 'mpltest.ttf'))
     mpl.rcParams["svg.fonttype"] = 'none'
     mpl.rcParams['mathtext.fontset'] = 'custom'
     mpl.rcParams['mathtext.rm'] = 'mpltest'
@@ -342,12 +371,13 @@ def test_mathtext_fallback(fallback, fontlist):
     fig, ax = plt.subplots()
     fig.text(.5, .5, test_str, fontsize=40, ha='center')
     fig.savefig(buff, format="svg")
-    char_fonts = [
-        line.split("font-family:")[-1].split(";")[0]
-        for line in str(buff.getvalue()).split(r"\n") if "tspan" in line
-    ]
+    tspans = (ET.fromstring(buff.getvalue())
+              .findall(".//{http://www.w3.org/2000/svg}tspan[@style]"))
+    # Getting the last element of the style attrib is a close enough
+    # approximation for parsing the font property.
+    char_fonts = [shlex.split(tspan.attrib["style"])[-1] for tspan in tspans]
     assert char_fonts == fontlist
-    mpl.font_manager.fontManager.ttflist = mpl.font_manager.fontManager.ttflist[:-1]
+    mpl.font_manager.fontManager.ttflist.pop()
 
 
 def test_math_to_image(tmpdir):