fix for --trim-file-names bug (#5526)

test/test_YoutubeDL.py

@@ -844,6 +844,15 @@ class TestYoutubeDL(unittest.TestCase):
         # test('%(foo|)s.%(ext)s', ('.mp4', '_.mp4'))  # fixme
         # test('%(foo|)s', ('', '_'))  # fixme
 
+        # Trim filename
+        test('%(id)s.%(filesize)s.%(ext)s', ('1234.1024.mp4', '123.mp4'), trim_file_name=3)
+        test(
+            '%(id)s.%(filesize)s.%(ext)s',
+            ('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)
+
         # Environment variable expansion for prepare_filename
         os.environ['__yt_dlp_var'] = 'expanded'
         envvar = '%__yt_dlp_var%' if compat_os_name == 'nt' else '$__yt_dlp_var'

yt_dlp/YoutubeDL.py

@@ -1379,6 +1379,12 @@ class YoutubeDL:
             if not filename:
                 return None
 
+            trim_file_name = self.params.get('trim_file_name', False)
+            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)
+                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')
                 if final_ext and ext and final_ext != ext and filename.endswith(f'.{final_ext}'):
@@ -1388,12 +1394,6 @@ class YoutubeDL:
                 if force_ext:
                     filename = replace_extension(filename, force_ext, info_dict.get('ext'))
 
-            # https://github.com/blackjack4494/youtube-dlc/issues/85
-            trim_file_name = self.params.get('trim_file_name', False)
-            if trim_file_name:
-                no_ext, *ext = filename.rsplit('.', 2)
-                filename = join_nonempty(no_ext[:trim_file_name], *ext, delim='.')
-
             return filename
         except ValueError as err:
             self.report_error('Error in output template: ' + str(err) + ' (encoding: ' + repr(preferredencoding()) + ')')

yt_dlp/utils/_utils.py

@@ -4733,7 +4733,7 @@ def number_of_digits(number):
 def join_nonempty(*values, delim='-', from_dict=None):
     if from_dict is not None:
         values = (traversal.traverse_obj(from_dict, variadic(v)) for v in values)
-    return delim.join(map(str, filter(None, values)))
+    return delim.join(str(v).strip() for v in values if v)
 
 
 def scale_thumbnails_to_max_format_width(formats, thumbnails, url_width_re):