ensure community always names an existing account. allow posting in unregistered communities.

hive/indexer/community.py

@@ -144,9 +144,8 @@ def is_community_post_valid(community, comment: dict) -> str:
 
     community_props = get_community(community)
     if not community_props:
-        # TODO: if a community is not found, assume it's completely open?
-        # all we need to do at that point is validate that its a valid acct name.
-        return False
+        # if this is not a defined community, it's free to post in.
+        return True
 
     if is_author_muted(author, community):
         return False

hive/indexer/core.py

@@ -115,8 +115,16 @@ def register_posts(ops, date):
             parent_id, parent_depth, category, community = parent_data
             depth = parent_depth + 1
 
+        # community must be an existing account
+        if not get_account_id(community):
+            print("Invalid community @{}/{} -- {}".format(op['author'], op['permlink'], community))
+            community = op['author']
+
+
         # validated community; will return None if invalid & defaults to author.
         is_valid = int(is_community_post_valid(community, op))
+        if not is_valid:
+            print("Invalid post @{}/{} in @{}".format(op['author'], op['permlink'], community))
 
         # if we're reusing a previously-deleted post (rare!), update it
         if id: