G_log_writer_func UNHANDLED

i think i didn’t understand how it works return G_LOG_WRITER_UNHANDLED on a GLogWriterFunc.

i setted a GLogWriterFunc with g_log_set_writer_func, and i expected that if i return G_LOG_WRITER_UNHANDLED libraries that i use output logs as normal; instead i get no log output at all

how can i output custom log messages based, for example, on some log fields, without “touch” other libraries output?

thanks in advance