Public bug reported:

In the beginning, CUPS shipped a pdftops filter based on the
/usr/bin/pdftops utility of Poppler. It produces DSC-conforming
PostScript which can easily be processed by further filters. It also
leaves text as text and embeds the fonts. Its problem is that it does
not support documents with multiple page sizes. In this case it scales
all pages to the size of the first page (bug 310575,
https://bugs.freedesktop.org/show_bug.cgi?id=19777).

To get around that, and also in the hope to get color management working
more quickly, I switched to Ghostscript for the pdftops filter in CUPS.
It solved the multiple-page-size problem perfectly but caused several
other problems.

I started with the "pswrite" output device of Ghostscript. Its output is
also DSC-conforming, but it turns all text characters to bitmaps,
causing huge PostScript files (bug 377011), broken text characters (bug
362186), slow job processing (bug 289852), output files which are not
searchable (bug 381788).

So I tried the "ps2write" output device of Ghostscript. Its output is
not DSC-conforming, so it can only be used in the pdftops filter when
the PDF workflow is used, where the page manipulations are done by the
pdftopdf filter which runs always before pdftops. In the upstream CUPS
without filter additions incoming PDF is turned to PostScript by the
pdftops filter and after that the pstops filter does the page management
and this requires DSC-conforming PostScript. It actually solved the
problems of "pswrite" producing a PostScript of reasonable size and with
embedded fonts, but it is still not perfect, for example it produces
code which does not run on some PostScript printers (bug 377011) and the
text searchability is also not perfect (bug 381788).

As it turns out that Ghostscript has too many problems in its two
PostScript output devices, I am looking into returning to Poppler, as
they have only the one minor problem of the multiple page size output,
which I have fixed. I have submitted the patch upstream (see
https://bugs.freedesktop.org/show_bug.cgi?id=19777) and I also attach a
debdiff for the Ubuntu package of Poppler. This adds a new output mode
to the PostScript output device of Poppler which conserves the original
page sizes and orientations.

Once this new Poppler versions is uploaded, we can change the pdftops
filter of CUPS to use Poppler and patch it to use the new
"-origpagesizes" option for the /usr/bin/pdftops call.

** Affects: poppler
     Importance: Unknown
         Status: Unknown

** Affects: cups (Ubuntu)
     Importance: High
         Status: Triaged

** Affects: poppler (Ubuntu)
     Importance: High
         Status: Triaged

** Also affects: cups (Ubuntu)
   Importance: Undecided
       Status: New

** Bug watch added: freedesktop.org Bugzilla #19777
   https://bugs.freedesktop.org/show_bug.cgi?id=19777

** Also affects: poppler via
   https://bugs.freedesktop.org/show_bug.cgi?id=19777
   Importance: Unknown
       Status: Unknown

** Changed in: cups (Ubuntu)
   Importance: Undecided => High

** Changed in: cups (Ubuntu)
       Status: New => Triaged

** Changed in: poppler (Ubuntu)
   Importance: Undecided => High

** Changed in: poppler (Ubuntu)
       Status: New => Triaged

-- 
pdftops CUPS filter has several problems
https://bugs.launchpad.net/bugs/382379
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