🐛 FIX: CLI crash on non-utf8 character (#247)

Addresses CVE-2023-26302

markdown_it/cli/parse.py

@@ -35,7 +35,7 @@ def convert_file(filename: str) -> None:
     Parse a Markdown file and dump the output to stdout.
     """
     try:
-        with open(filename, "r") as fin:
+        with open(filename, "r", encoding="utf8", errors="ignore") as fin:
             rendered = MarkdownIt().render(fin.read())
             print(rendered, end="")
     except OSError:

tests/test_cli.py

@@ -20,6 +20,13 @@ def test_parse_fail():
     assert exc_info.value.code == 1
 
 
+def test_non_utf8():
+    with tempfile.TemporaryDirectory() as tempdir:
+        path = pathlib.Path(tempdir).joinpath("test.md")
+        path.write_bytes(b"\x80abc")
+        assert parse.main([str(path)]) == 0
+
+
 def test_print_heading():
     with patch("builtins.print") as patched:
         parse.print_heading()