Re: Fwd: Extra Blank page being printed

At 07:58 16/03/2016 +0000, Ken Sharp wrote:


>The system converts PDFs to PostScript which are concatenated and then 
>printed. An extra "image" is printing after the fourth "page", making the 
>duplex printing out of sequence. Can anyone suggest why? This question is 
>a desperation move...

Firstly this is not a forum for support but for programming questions 
relating to developing software which interfaces to the Ghostscript internals.

If you think you have uncovered a bug you may open a bug report at 
bugs.ghostscript.com don't forget to include an example file, and command 
line required to reproduce the problem.


>It prints in Duplex, so if I say "page" here, I mean 2 images, one front 
>and one back on a sheet of paper. Usually the back one is blank
>The application generates "User Letters" that are two pages, a Coversheet 
>and a "User Document" concatenated together using a Byte copy.

PostScript is a programming language, PostScript files are programs. 
Effectively you are concatenating two programs together, do you think this 
is likely to work ?

While it will, for some cases, especially simple cases, in general 
concatenating PostScript programs is well known to fail, sometimes 
spectacularly. This is not a sensible approach to whatever your problem is.


>The Coversheet is a generic PostScript (mostly static) file created by 
>Microsoft Word.
>The User Document is converted from PDF to PostScript with GhostScript.
>%%Creator: GPL Ghostscript GIT PRERELEASE 908 (ps2write)
>
>It has a duplex command inserted thus above the BeginProlog statement.:
><< /Duplex true >> setpagedevice

Well that will likely be the start if your problems, each invocation of 
setpagedevice 'resets' the device. Assuming your printer was initially in 
duplex mode, issuing a new setpagedevice will (normally) cause the printer 
to eject the page by printing a blank page and restarting in duplex mode.


>If converted to PDF from PostScript, the User Letter is always 2 pages. 
>There is no blank image.

Sounds to me exactly what I would expect to happen by meddling with the 
duplex setting and issuing a setpagedevice on every other page.


>... Maybe it is the printer...  Thank you for any suggestions, Michael

Beyond the above, there is nothing I can possibly say without seeing the 
programs. Nothing here makes me think there is any problem beyond your 
insertion of setpagedevice operators though.


                 Ken