Fix file name could be lost when uploading files

Leading to invalid extension when sending photos.

telethon/client/uploads.py

@@ -90,6 +90,7 @@ def _resize_photo_if_needed(
         buffer = io.BytesIO()
         result.save(buffer, 'JPEG', progressive=True, **kwargs)
         buffer.seek(0)
+        buffer.name = getattr(file, 'name', None)
         return buffer
     except IOError:
         return file

telethon/helpers.py

@@ -348,21 +348,22 @@ async def __aenter__(self):
             self._size = os.path.getsize(self._file)
             self._stream = open(self._file, 'rb')
             self._close_stream = True
+            return self
 
-        elif isinstance(self._file, bytes):
+        if isinstance(self._file, bytes):
             self._size = len(self._file)
             self._stream = io.BytesIO(self._file)
             self._close_stream = True
+            return self
 
-        elif not callable(getattr(self._file, 'read', None)):
+        if not callable(getattr(self._file, 'read', None)):
             raise TypeError('file description should have a `read` method')
 
-        elif self._size is not None:
-            self._name = getattr(self._file, 'name', None)
-            self._stream = self._file
-            self._close_stream = False
+        self._name = getattr(self._file, 'name', None)
+        self._stream = self._file
+        self._close_stream = False
 
-        else:
+        if self._size is None:
             if callable(getattr(self._file, 'seekable', None)):
                 seekable = await _maybe_await(self._file.seekable())
             else:
@@ -373,8 +374,6 @@ async def __aenter__(self):
                 await _maybe_await(self._file.seek(0, os.SEEK_END))
                 self._size = await _maybe_await(self._file.tell())
                 await _maybe_await(self._file.seek(pos, os.SEEK_SET))
-                self._stream = self._file
-                self._close_stream = False
             else:
                 _log.warning(
                     'Could not determine file size beforehand so the entire '

telethon/version.py

@@ -1,3 +1,3 @@
 # Versions should comply with PEP440.
 # This line is parsed in setup.py:
-__version__ = '1.31.0'
+__version__ = '1.31.1'