cfFilterBannerToPDF() output is truncated (missing xref and %%EOF) when run inside cfFilterChain() — breaks CUPS test page printing

[RiderALT]

Printing the CUPS test page (application/vnd.cups-pdf-banner) through the universal filter fails:

E [Job 1] cfFilterChain: pdftopdf (PID 4813) stopped with status 1
E [Job 1] PID 4810 (/usr/lib/cups/filter/universal) stopped with status 1.

The PDF produced by cfFilterBannerToPDF() is truncated at a 4096-byte boundary and lacks the xref table and the %%EOF marker, so the next filter in the chain (cfFilterPDFToPDF, backed by PDFio) cannot open it and exits with status 1.

Affected: 2.2.0, 2.2.1 and current master (the PDFio-based bannertopdf rewrite). PR #154 ("Fix for issue of incomplete bannertopdf") did not fully fix this. Originally reported downstream at ALT Linux: https://bugzilla.altlinux.org/60277

[RiderALT]

cfFilterBannerToPDF() never closes the FILE * it fdopen()s on outputfd, so the buffered tail of the PDF (xref table, %%EOF) is lost when the caller (e.g. a cfFilterChain() child) closes the fd before exit() — adding fclose(outputfp); before the final return fixes the truncated banner/test-page output.

[tangyanli]

#167

[ValdikSS]

Not fixed as of 2.2.1 + #167 (ArchLinux libcupsfilters 2.2.1-2).

It seems to be a universal issue and/or pdftopdf issue.

• When testprint is handled by bannertopdf + pdftopdf, the output PDF is missing the image
• When testprint is handled by cupsfilter (universal), the PDF is broken

Mutool says this in the second case:

format error: cannot find startxref
warning: trying to repair broken xref
warning: repairing PDF document

@tillkamppeter @uddhavphatak

out.pdf

[uddhavphatak]

@ValdikSS could you please help me reproduce the issue, how do I use the "universal" filter, any background will help me with understanding reproduction steps, and troubleshooting the bug

[ValdikSS]

@uddhavphatak universal filter seems to be unconditionally enabled by default (OpenPrinting/cups-filters#724)

On ArchLinux with the latest cups-filters and libcupsfilters release, cupsfilter uses universal by default. If you don't --enable-individual-cups-filters for cups-filters, universal will be built and used.

# cupsfilter -P any-ppd-here.ppd -m application/pdf /usr/share/cups/data/testprint > out.pdf

[rilian-la-te]

Yes, looks like bannertopdf issue. And universal too.