Fix exception handling in FT2Font init.

QuLogic · QuLogic · commit f0e270cd32b3 · 2020-05-25T22:11:51.000-04:00
It needs to return -1 when an exception is set, or Python raises a
`SystemError` instead.
diff --git a/lib/matplotlib/tests/test_font_manager.py b/lib/matplotlib/tests/test_font_manager.py
@@ -1,4 +1,4 @@
-from io import BytesIO
+from io import BytesIO, StringIO
 import multiprocessing
 import os
 from pathlib import Path
@@ -128,6 +128,24 @@ def test_find_ttc():
         fig.savefig(BytesIO(), format="ps")
 
 
+def test_find_invalid(tmpdir):
+    tmp_path = Path(tmpdir)
+
+    with pytest.raises(FileNotFoundError):
+        get_font(tmp_path / 'non-existent-font-name.ttf')
+
+    with pytest.raises(FileNotFoundError):
+        get_font(str(tmp_path / 'non-existent-font-name.ttf'))
+
+    with pytest.raises(FileNotFoundError):
+        get_font(bytes(tmp_path / 'non-existent-font-name.ttf'))
+
+    # Not really public, but get_font doesn't expose non-filename constructor.
+    from matplotlib.ft2font import FT2Font
+    with pytest.raises(TypeError, match='path or binary-mode file'):
+        FT2Font(StringIO())
+
+
 @pytest.mark.skipif(sys.platform != 'linux', reason='Linux only')
 def test_user_fonts_linux(tmpdir, monkeypatch):
     font_test_file = 'mpltest.ttf'
diff --git a/src/ft2font_wrapper.cpp b/src/ft2font_wrapper.cpp
@@ -461,6 +461,7 @@ static int PyFT2Font_init(PyFT2Font *self, PyObject *args, PyObject *kwds)
     long hinting_factor = 8;
     int kerning_factor = 0;
     const char *names[] = { "filename", "hinting_factor", "_kerning_factor", NULL };
+    int ret = 0;
 
     if (!PyArg_ParseTupleAndKeywords(
              args, kwds, "O|l$i:FT2Font", (char **)names, &filename,
@@ -480,6 +481,7 @@ static int PyFT2Font_init(PyFT2Font *self, PyObject *args, PyObject *kwds)
     if (PyBytes_Check(filename) || PyUnicode_Check(filename)) {
         if (!(open = PyDict_GetItemString(PyEval_GetBuiltins(), "open"))  // Borrowed reference.
             || !(self->py_file = PyObject_CallFunction(open, "Os", filename, "rb"))) {
+            ret = -1;
             goto exit;
         }
         self->stream.close = &close_file_callback;
@@ -488,12 +490,14 @@ static int PyFT2Font_init(PyFT2Font *self, PyObject *args, PyObject *kwds)
                || !PyBytes_Check(data)) {
         PyErr_SetString(PyExc_TypeError,
                         "First argument must be a path or binary-mode file object");
+        ret = -1;
         goto exit;
     } else {
         self->py_file = filename;
         self->stream.close = NULL;
         Py_INCREF(filename);
     }
+    Py_CLEAR(data);
 
     CALL_CPP_FULL(
         "FT2Font", (self->x = new FT2Font(open_args, hinting_factor)),
@@ -507,7 +511,7 @@ static int PyFT2Font_init(PyFT2Font *self, PyObject *args, PyObject *kwds)
 exit:
     Py_XDECREF(data);
 
-    return 0;
+    return ret;
 }
 
 static void PyFT2Font_dealloc(PyFT2Font *self)
