bluesky.from_as1: ignore contentMap languages that aren't valid BCP47…

…/RFC5646

fixes https://console.cloud.google.com/errors/detail/CICQ0JPQn6nqpQE;time=P1D;locations=global?project=bridgy-federated&inv=1&invt=Abj5Qw

granary/bluesky.py

@@ -17,7 +17,7 @@
 
 from bs4 import BeautifulSoup
 from lexrpc import Client
-from lexrpc.base import Base, NSID_RE
+from lexrpc.base import Base, LANG_RE, NSID_RE
 from multiformats import CID
 from oauth_dropins.webutil import util
 from oauth_dropins.webutil.util import trim_nulls
@@ -955,7 +955,7 @@ def from_as1(obj, out_type=None, blobs=None, aspects=None, client=None,
       embed = {
         '$type': 'app.bsky.embed.recordWithMedia#view',
         'record': record_embed,
-        'media': media_embed
+        'media': media_embed,
       }
     else:
       embed = record_embed or media_embed
@@ -986,7 +986,8 @@ def from_as1(obj, out_type=None, blobs=None, aspects=None, client=None,
     # languages
     # (we steal contentMap from AS2, it's not officially part of AS1)
     langs = [lang for lang, lang_content in obj.get('contentMap', {}).items()
-             if lang_content == orig_content]
+             if LANG_RE.match(lang)
+             and lang_content == orig_content]
 
     # convert AS1 sensitive to "nudity" label
     # https://github.com/snarfed/atproto/blob/f2f8de63b333448d87c364578e023ddbb63b8b25/lexicons/com/atproto/label/defs.json#L139-L154

granary/tests/test_bluesky.py

@@ -1663,6 +1663,19 @@ def test_from_as1_post_langs(self):
       },
     }))
 
+  def test_from_as1_post_bad_lang(self):
+    self.assert_equals({
+      '$type': 'app.bsky.feed.post',
+      'text': 'My original post',
+      'createdAt': '2022-01-02T03:04:05.000Z',
+    }, from_as1({
+      'objectType': 'note',
+      'content': 'My original post',
+      'contentMap': {
+        'unknown': 'My original post',
+      },
+    }))
+
   def test_from_as1_post_langs_none_match_content(self):
     self.assert_equals({
       '$type': 'app.bsky.feed.post',