When researching 2770, it was discovered that on AIX dochild was failing. This is due to the ioctl(slave,I_PUSH,"ldterm"); If ldterm is already present on the stream, the child will hang. This will subsequently cause the parent to fail on talktochild().
Created attachment 1684 [details] fix for ioctl hang. This makes a check on ptem and ldterm before attempting to add the module to the stream.
Applied, thanks ! Jeremy.