Expose MySQL connection state

src/lib/mysql-connector.h

@@ -71,6 +71,14 @@ inline MySQL* mysql_connect(String host = "localhost", String username = "root",
 	return(db);
 }
 
+// A failed connection retains a request-owned wrapper so mysql_error() remains
+// available. Callers that need to decide whether to issue work must test the
+// connection state rather than only the wrapper pointer.
+inline bool mysql_connected(MySQL* m)
+{
+	return(m != 0 && m->connection != 0);
+}
+
 inline void mysql_disconnect(MySQL* m)
 {
 	if(!m)