Support (first font of) TTC files.

TTC is a TrueType Collection file (a collection of TTFs). Currently, ft2font only supports getting the first font from the collection, and neither the pdf nor ps backends are able to use them (due to limitations of ttconv). Still, it seems better than nothing to support them for Agg and SVG (that comes for free via FreeType).
matplotlib · jklymak · Jan 4, 2019 · Nov 15, 2017 · Nov 25, 2018 · Jan 2, 2019
commit ae618f34f367cf5cd3cfba004271071eb2b6cae9
diff --git a/.travis.yml b/.travis.yml
@@ -43,6 +43,7 @@ addons:
       - texlive-latex-recommended
       - texlive-xetex
       - texlive-luatex
+      - ttf-wqy-zenhei
 
 env:
   global:
@@ -110,7 +111,7 @@ before_install: |
     ci/silence brew update
     brew uninstall numpy gdal postgis
     brew upgrade python
-    brew install ffmpeg imagemagick mplayer ccache
+    brew install ffmpeg imagemagick mplayer ccache font-wenquanyi-zen-hei
     hash -r
     which python
     python --version

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -973,8 +973,13 @@ def get_char_width(charcode):
 
             # Make the charprocs array (using ttconv to generate the
             # actual outlines)
-            rawcharprocs = ttconv.get_pdf_charprocs(
-                os.fsencode(filename), glyph_ids)
+            try:
+                rawcharprocs = ttconv.get_pdf_charprocs(
+                    os.fsencode(filename), glyph_ids)
+            except RuntimeError:
+                _log.warning("The PDF backend does not currently support the "
+                             "selected font.")
+                raise
             charprocs = {}
             for charname in sorted(rawcharprocs):
                 stream = rawcharprocs[charname]

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -1117,8 +1117,14 @@ def print_figure_impl(fh):
                                 "time; consider using the Cairo backend")
                         else:
                             fh.flush()
-                            convert_ttf_to_ps(os.fsencode(font_filename),
-                                              fh, fonttype, glyph_ids)
+                            try:
+                                convert_ttf_to_ps(os.fsencode(font_filename),
+                                                  fh, fonttype, glyph_ids)
+                            except RuntimeError:
+                                _log.warning("The PostScript backend does not "
+                                             "currently support the selected "
+                                             "font.")
+                                raise
             print("end", file=fh)
             print("%%EndProlog", file=fh)
 

diff --git a/lib/matplotlib/font_manager.py b/lib/matplotlib/font_manager.py
@@ -129,9 +129,12 @@ def get_fontext_synonyms(fontext):
     Return a list of file extensions extensions that are synonyms for
     the given file extension *fileext*.
     """
-    return {'ttf': ('ttf', 'otf'),
-            'otf': ('ttf', 'otf'),
-            'afm': ('afm',)}[fontext]
+    return {
+        'afm': ['afm'],
+        'otf': ['otf', 'ttc', 'ttf'],
+        'ttc': ['otf', 'ttc', 'ttf'],
+        'ttf': ['otf', 'ttc', 'ttf'],
+    }[fontext]
 
 
 def list_fonts(directory, extensions):

diff --git a/lib/matplotlib/tests/test_font_manager.py b/lib/matplotlib/tests/test_font_manager.py
@@ -1,3 +1,5 @@
+from io import BytesIO
+import os
 from pathlib import Path
 import shutil
 import sys
@@ -9,7 +11,7 @@
 from matplotlib.font_manager import (
     findfont, FontProperties, fontManager, json_dump, json_load, get_font,
     get_fontconfig_fonts, is_opentype_cff_font)
-from matplotlib import rc_context
+from matplotlib import pyplot as plt, rc_context
 
 has_fclist = shutil.which('fc-list') is not None
 
@@ -91,7 +93,7 @@ def test_hinting_factor(factor):
 
 
 @pytest.mark.skipif(sys.platform != "win32",
-                   reason="Need Windows font to test against")
+                    reason="Need Windows font to test against")
 def test_utf16m_sfnt():
     segoe_ui_semibold = None
     for f in fontManager.ttflist:
@@ -105,3 +107,20 @@ def test_utf16m_sfnt():
     # Check that we successfully read the "semibold" from the font's
     # sfnt table and set its weight accordingly
     assert segoe_ui_semibold.weight == "semibold"
+
+
+@pytest.mark.xfail(not (os.environ.get("TRAVIS") and sys.platform == "linux"),
+                   reason="Font may be missing.")
+def test_find_ttc():
+    fp = FontProperties(family=["WenQuanYi Zen Hei"])
+    font = findfont(fp)
+    assert Path(font).name == "wqy-zenhei.ttc"
+
+    fig, ax = plt.subplots()
+    ax.text(.5, .5, "\N{KANGXI RADICAL DRAGON}", fontproperties=fp)
+    fig.savefig(BytesIO(), format="raw")
+    fig.savefig(BytesIO(), format="svg")
+    with pytest.raises(RuntimeError):
+        fig.savefig(BytesIO(), format="pdf")
+    with pytest.raises(RuntimeError):
+        fig.savefig(BytesIO(), format="ps")