[ytdl} fix dfe4f00c for legacy yt-dlp

gallery_dl/ytdl.py

@@ -199,18 +199,27 @@ def parse_command_line(module, argv):
                     action += args
                     yield action
 
-        if opts.metafromtitle is not None:
+        parse_metadata = getattr(opts, "parse_metadata", None)
-            if "pre_process" not in opts.parse_metadata:
+        if isinstance(parse_metadata, dict):
-                opts.parse_metadata["pre_process"] = []
+            if opts.metafromtitle is not None:
-            opts.parse_metadata["pre_process"].append(
+                if "pre_process" not in parse_metadata:
-                "title:%s" % opts.metafromtitle)
+                    parse_metadata["pre_process"] = []
-            opts.metafromtitle = None
+                parse_metadata["pre_process"].append(
+                    "title:%s" % opts.metafromtitle)
+            opts.parse_metadata = {
+                k: list(itertools.chain.from_iterable(map(
+                        metadataparser_actions, v)))
+                for k, v in parse_metadata.items()
+            }
+        else:
+            if parse_metadata is None:
+                parse_metadata = []
+            if opts.metafromtitle is not None:
+                parse_metadata.append("title:%s" % opts.metafromtitle)
+            opts.parse_metadata = list(itertools.chain.from_iterable(map(
+                metadataparser_actions, parse_metadata)))
 
-        opts.parse_metadata = {
+        opts.metafromtitle = None
-            k: list(itertools.chain.from_iterable(map(
-                    metadataparser_actions, v)))
-            for k, v in opts.parse_metadata.items()
-        }
     else:
         opts.parse_metadata = ()
 

test/test_ytdl.py

@@ -262,15 +262,21 @@ class Test_CommandlineArguments_YtDlp(Test_CommandlineArguments):
 
     def test_metadata_from_title(self):
         opts = self._(["--metadata-from-title", "%(artist)s - %(title)s"])
+
+        try:
+            legacy = (self.module.version.__version__ < "2023.01.01")
+        except AttributeError:
+            legacy = True
+
+        actions = [self.module.MetadataFromFieldPP.to_action(
+                   "title:%(artist)s - %(title)s")]
+        if not legacy:
+            actions = {"pre_process": actions}
+
         self.assertEqual(opts["postprocessors"][0], {
             "key"    : "MetadataParser",
             "when"   : "pre_process",
-            "actions": {
+            "actions": actions,
-                "pre_process": [
-                    self.module.MetadataFromFieldPP.to_action(
-                        "title:%(artist)s - %(title)s")
-                ],
-            },
         })