+static void
+_thread_add_author (notmuch_thread_t *thread,
+ const char *author)
+{
+ if (author == NULL)
+ return;
+
+ if (g_hash_table_lookup_extended (thread->authors_hash,
+ author, NULL, NULL))
+ return;
+
+ g_hash_table_insert (thread->authors_hash, xstrdup (author), NULL);
+
+ if (thread->authors)
+ thread->authors = talloc_asprintf (thread, "%s, %s",
+ thread->authors,
+ author);
+ else
+ thread->authors = talloc_strdup (thread, author);
+}
+