update

Author: jaredmauch

Mailman/Mailbox.py

@@ -45,27 +45,36 @@ class BinaryGenerator(email.generator.Generator):
     """A generator that writes to a binary file."""
     def __init__(self, outfp, mangle_from_=True, maxheaderlen=78, *args, **kwargs):
         # Create a text buffer that we'll write to first
-        self._buffer = BytesIO()
+        self._buffer = StringIO()
         super().__init__(self._buffer, mangle_from_, maxheaderlen, *args, **kwargs)
         # Store the binary file object
         self._binary_fp = outfp
 
+    def write(self, s):
+        """Override write to handle string-to-bytes conversion."""
+        if isinstance(s, str):
+            s = s.encode('utf-8', 'replace')
+        self._buffer.write(s)
+
     def _write_lines(self, lines):
-        # Override to handle both string and bytes input
+        """Override to handle both string and bytes input."""
         for line in lines:
-            if isinstance(line, str):
-                line = line.encode('utf-8', 'replace')
+            if isinstance(line, bytes):
+                try:
+                    line = line.decode('utf-8', 'replace')
+                except UnicodeError:
+                    line = line.decode('latin-1', 'replace')
             self._buffer.write(line)
 
     def flatten(self, msg, unixfrom=False, linesep='\n'):
-        # Override to write the buffer contents to binary file
-        super().flatten(msg, unixfrom=unixfrom, linesep=linesep)
-        # Get the content and write it directly to binary file
-        content = self._buffer.getvalue()
+        """Override to write the buffer contents to binary file."""
         # Reset the buffer
         self._buffer.seek(0)
         self._buffer.truncate()
-        # Write to binary file
+        # Write the message to the buffer
+        super().flatten(msg, unixfrom=unixfrom, linesep=linesep)
+        # Get the content and write it to binary file
+        content = self._buffer.getvalue().encode('utf-8', 'replace')
         self._binary_fp.write(content)