mod_bookmarks: Suppress error publishing empty legacy bookmarks w/ no PEP node

It appears that when:

1) The user has no bookmarks 2 node in PEP
2) The client publishes an empty bookmark set to a legacy bookmarks location
3) mod_bookmarks will attempt to purge items from the non-existent node and
   log an error about the failure (item-not-found).

This new code will suppress an item-not-found error from the purge operation
in the empty-bookmarks case, and adds a log message for any other error (this
is helpful because the existing log message confusingly says it was an error
*publishing* to the node, which isn't always accurate).

1 files changed, 8 insertions, 3 deletions

diff --git a/plugins/mod_bookmarks.lua b/plugins/mod_bookmarks.lua
index d67915f8..8fe3166a 100644
--- a/plugins/mod_bookmarks.lua
+++ b/plugins/mod_bookmarks.lua
@@ -167,10 +167,15 @@ local function publish_to_pep(jid, bookmarks, synchronise)
 		if synchronise then
 			-- If we set zero legacy bookmarks, purge the bookmarks 2 node.
 			module:log("debug", "No bookmark in the set, purging instead.");
-			return service:purge(namespace, jid, true);
-		else
-			return true;
+			local ok, err = service:purge(namespace, jid, true);
+			-- It's okay if no node exists when purging, user has
+			-- no bookmarks anyway.
+			if not ok and err ~= "item-not-found" then
+				module:log("error", "Failed to clear items from bookmarks 2 node: %s", err);
+				return ok, err;
+			end
 		end
+		return true;
 	end
 
 	-- Retrieve the current bookmarks2.