CUPS does not downgrade PS version if printer/PPD requires it

[michaelrsweet]

Version: 1.1.17
CUPS.org User: greenfeld.2.osu

If a user submits a higher level of version of Postscript than a printer supports, CUPS does not attempt to downgrade the version of Postscript used or refuse to print the file. Detection of the Postscript version supported by a printer should be possible via the "LanguageLevel" parameter found in many (but not all!) PPD files.

I assume you can default to allowing printing reguardless of the Postscript level when you do not know what is supported, but if a PPD specifies a maximum level of Postscript support, it should be honored.

Example scenario: A user prints out a file with a header of "%!PS-Adobe-3.0". But the printer only supports Postscript level 2. CUPS still sends the file as Postscript level 3 data to the printer, possibly including some Type 3 (?) fonts.

In response, the printer may refuse to print the job, or in the case of certain printers (such as our HP 4000 at work) hang until reset. (And yes, our PPD for the HP 4000 specifies *LanguageLevel: "2")

[michaelrsweet]

CUPS.org User: mike

You are confusing the DSC version number (the PS-Adobe-3.0) and the language level (which, if present, is supplied in the LanguageLevel comment). The DSC version number has nothing to do with the PostScript language level, and DSC 3.0 does in fact support Level 1 PostScript in addition to Level 2 and Level 3.

As for "Type 3" fonts, they are supported by all PostScript printers.

More than likely you are just running into a PS interpreter bug in the HP 4000 (there are several in the TrueType font support, along with a handful of other esoteric problems).

To "fix" the problem, use the PCL driver included with CUPS (laserjet.ppd) or try Till's foomatic driver for the 4000 - it uses Ghostscript to provide "optimized" PostScript for the printer which may work better for you... There is also a PCL 6 driver which will provide you with 1200 DPI support (the CUPS PCL 5 driver is limited to 600 DPI due to PCL 5's limit of 600 DPI...)