Small refactor of the new content-disposition parsing

sabnzbd/urlgrabber.py

@@ -60,27 +60,6 @@ _RARTING_FIELDS = (
 )
 
 
-def filename_from_content_disposition(content_disposition):
-    """
-    Extract and validate filename from a Content-Disposition header.
-
-    Origin: https://github.com/httpie/httpie/blob/4c8633c6e51f388523ab4fa649040934402a4fc9/httpie/downloads.py#L98
-    :param content_disposition: Content-Disposition value
-    :type content_disposition: str
-    :return: the filename if present and valid, otherwise `None`
-    :example:
-        filename_from_content_disposition('attachment; filename=jakubroztocil-httpie-0.4.1-20-g40bd8f6.tar.gz')
-        should return: 'jakubroztocil-httpie-0.4.1-20-g40bd8f6.tar.gz'
-    """
-    msg = Message(f"Content-Disposition: attachment; {content_disposition}")
-    filename = msg.get_filename()
-    if filename:
-        # Basic sanitation.
-        filename = os.path.basename(filename).lstrip(".").strip()
-        if filename:
-            return filename
-
-
 class URLGrabber(Thread):
     def __init__(self):
         super().__init__()
@@ -391,3 +370,23 @@ def _analyse(fetch_request: HTTPResponse, future_nzo: NzbObject):
         return None, msg, True, when, data
 
     return fetch_request, fetch_request.msg, False, 0, data
+
+
+def filename_from_content_disposition(content_disposition: str) -> Optional[str]:
+    """
+    Extract and validate filename from a Content-Disposition header.
+
+    Origin: https://github.com/httpie/httpie/blob/4c8633c6e51f388523ab4fa649040934402a4fc9/httpie/downloads.py#L98
+    :param content_disposition: Content-Disposition value
+    :type content_disposition: str
+    :return: the filename if present and valid, otherwise `None`
+    :example:
+        filename_from_content_disposition('attachment; filename=jakubroztocil-httpie-0.4.1-20-g40bd8f6.tar.gz')
+        should return: 'jakubroztocil-httpie-0.4.1-20-g40bd8f6.tar.gz'
+    """
+    filename = Message(f"Content-Disposition: attachment; {content_disposition}").get_filename()
+    if filename:
+        # Basic sanitation
+        filename = os.path.basename(filename).lstrip(".").strip()
+        if filename:
+            return filename