Changeset 4555bc1e in rtems for cpukit/libcsupport/src/termios.c

Initialized tty->refcount to 0. When (for whatever reason) malloc()
returned a buffer which was not zero-filled, the reference count
was not correct. When the application exitted, the "lastClose"
handler was not being called to flush the output. This problem
had manifested itself on a variety of platforms.

The function rtems_termios_dequeue_characters() incorrectly incremented
the buffer pointers when it was invoked and there were no characters
in the ring buffer. This problem had also manifested itself on a
variety of platforms. The symptom was a strange repeating of the
data in the transmitter buffer when the transmitter serial device
was supposed to go idle.