search_query.c: zero-out folder->esearch before using it

Author: ksmurchison

Diff for: imap/search_query.c

@@ -601,6 +601,7 @@ static int _subquery_run_one_folder(search_query_t *query,
                 }
             }
 
+            memset(&folder->esearch, 0, sizeof(folder->esearch));
             folder->esearch.min_uid = state->last_uid + 1;
         }