That's the thing: we have file systems with transparent compression nowadays (and to think this started with Stacker on MS-DOS!), so it makes sense to use **uncompressed** WARC files on a BTRFS or NTFS with it activated. This commit deactivates the WARCIO gzip support when the filename **does not** ends with .gz, allowing the user to use these filesystems to reach the compression he wants without having to deal with uncompressing the WARC on use.

for https://github.com/webrecorder/pywb/issues/915

pywb/recorder/multifilewarcwriter.py

@@ -32,6 +32,7 @@ class MultiFileWARCWriter(BaseWARCWriter):
         self.dedup_index = kwargs.get('dedup_index')
         self.dedup_by_url = kwargs.get('dedup_by_url')
         self.filename_template = filename_template
+        self.gzip = self.filename_template.endswith(".gz")
         self.max_size = max_size
         if max_idle_secs > 0:
             self.max_idle_time = datetime.timedelta(seconds=max_idle_secs)