[pdftex] pdftex deterministic?

[Matteo Centonza]

On Sat, 2007-03-31 at 11:43 -0400, Geoffrey Alan Washburn wrote:
> 	I could swear I had read something about this in the past, but I 
> couldn't remember the correct keywords to find anything via search.  In 
> any event, I recently wanted to make some changes to a the source of a 
> document and to make sure that these changes did not actually affect the 
> document I tried diffing the before and after PDFs.  Unfortunately, 
> after some further experimentation it does not seem that even repeated 
> runs of the same document produce identical output.  Is there any way I 
> can modify my documents or the parameters to pdftex to produce identical 
> output on identical inputs?  I realize this very well may not be 
> possible, and if so, what alternatives do people use in practice?  Thanks!

Hi,

thanks for having asked this since it was long in my
list of things to ask. IMO, the option
to rapidly check two PDFs is a must in a production
environment in order to sort out any regression.

I've slightly modified dvips sources in the past,
in order to have PS compared by their checksums.
I suppose that the same could be done in pdftex.

Could this QA mode be an useful addition?

Waiting for comments,

-m