pdftops filter should obey page-ranges option

[michaelrsweet]

Version: 1.2-feature
CUPS.org User: h.blischke

The pdftops filter, if invoked in the filter chain, should
already evaluate the page-ranges attribute.
In this case the attribute would have to be modified in order not to disturbe the pstops filter.

Otherwise (e.g. need only pages 1-10 out of some 50.000) the pdftops filter consumes too much resources.

[michaelrsweet]

CUPS.org User: mike

Since pdftops produces application/postscript output, we want the CUPS filter system to be generic, and we would need to add ALL of the pstops capabilities to pdftops, it is unlikely that we will change the pdftops filter in the way you suggest.

It is possible that we could update the filter to output blank pages (no page object processing == faster) for those pages that are excluded from the page-ranges and page-set attributes, however this will likely not happen until CUPS 1.2.

[michaelrsweet]

CUPS.org User: h.blischke

The solution sketched out seems acceptable to me, and to postpone it until CUPS 1.2 is ok.

[michaelrsweet]

CUPS.org User: mike

Fixed in Subversion repository.