[Samba] Truncated print jobs - MS-DOS clients

[n***@sapo.pt]

Hi Everyone,

Having problem wuth truncated print jobs, I'm looking for help:

- New server with Samba 4.4.3 compiled from source, Linux Centos 7.2 x86_64;
- with patched source3/smbd/reply.c to avoid truncated smbd replies to
old clients, as provided by Jeremy here:
http://samba-technical.samba.narkive.com/g3YL4vmY/dos-clients-slow-on-samba-4-1-7-bug-10422
(works perfect, thanks!)
- Several Win10, Win7, WinXP and a few MS-DOS 6.22 clients;
- All shares are xfs filesystems (ext4 avoided, as MS-DOS clients
suffer from infinite repeated dir filename)
- With 1 ipp raw queue printer shared by Samba as "\\newserver\laser"

Scenario: sending plain text file to captured printer port:

copy xpto.txt lpt1

- XP, Win7 clients: Works perfect, instant and correct printing.
- MS-DOS Clients: machine stays "locked" for exactly 45 seconds, then
the ipp printer starts printing, but only the first 124 bytes appear
on paper.

CUPS spool dir keeps files. Those coming from MS-DOS clients allways
show length 124 bytes. Other coming form XP/Win 7 show their correct
sizes.

-x-

The old production server is in the same network (Centos 5.11 i686,
Samba 3.0.33 via rpm), and sharing the very same ipp printer as
"\\server\laser"

- All clients, including MS-DOS: instant and correct printing.


My questions:

Could there be something similar to the truncated replies for MS-DOS
clients relating to printer jobs ? Could somebody possibly point me
some direction to search for solution ?

File sharing is working perfectly on new server, locks dully respected.

TIA
António