do not strip whitespace characters

test/test_YoutubeDL.py

@@ -851,7 +851,7 @@ class TestYoutubeDL(unittest.TestCase):
             ('1234.1024.info.json', '123.info.json'),
             info=dict(self.outtmpl_info, ext='info.json'), trim_file_name=3
         )
-        test('12 34.%(filesize)s.%(ext)s', ('12 34.1024.mp4', '12.mp4'), trim_file_name=3)
+        test('12 34.%(filesize)s.%(ext)s', ('12 34.1024.mp4', '12 .mp4'), trim_file_name=3)
 
         # Environment variable expansion for prepare_filename
         os.environ['__yt_dlp_var'] = 'expanded'

yt_dlp/YoutubeDL.py

@@ -1383,9 +1383,7 @@ class YoutubeDL:
             if trim_file_name:
                 # https://github.com/yt-dlp/yt-dlp/issues/5526#issuecomment-1312783517
                 no_ext, *ext = filename.rsplit('.', info_dict.get('ext', '').count('.') + 1)
-                # cut filename and remove trailing spaces and extra dots
-                name = no_ext[:trim_file_name].strip().rstrip('.')
-                filename = join_nonempty(name, *ext, delim='.')
+                filename = join_nonempty(no_ext[:trim_file_name], *ext, delim='.')
 
             if tmpl_type in ('', 'temp'):
                 final_ext, ext = self.params.get('final_ext'), info_dict.get('ext')