Bug#895487: libpoppler-glib8: poppler 0.62 has very slow cairo rendering

[Rogério Brito]

Package: libpoppler-glib8
Version: 0.62.0-2
Severity: important
Tags: upstream

Hi.

With moderately recent versions of poppler (approximately from 0.60 to 0.62,
but possibly earlier than 0.60), poppler has changed the Cairo rendering
from using the GOOD downscaling to BEST downscaling.

This affects potentially the usability of all PDF files that contain scanned
pages by slowly presenting them (especially on less powerful machines, but
also on amd64 machines).

The problem is recognized upstream [0] and the change [1] was reverted in
version 0.63 [2] of poppler.  In fact, even cairo's documentation says that
BEST "may not be suitable for interactive use" [3].


[0]: https://bugs.freedesktop.org/show_bug.cgi?id=103136
[1]: https://cgit.freedesktop.org/poppler/poppler/commit/?id=4afe2fb10ab969bfd9895c0ba9d4990c5881b451
[2]: https://cgit.freedesktop.org/poppler/poppler/tree/NEWS?id=f26285f361478219ea9d3c6de1529ecd5ff96ac9#n5
[3]: https://www.cairographics.org/manual/cairo-cairo-pattern-t.html#cairo-filter-t


Note that the qt5 version of the package doesn't contain this slowdown and,
for parity between versions (tested with qpdfview), it would be nice to
have similar performance between, say, evince/atril and qpdfview...

Given the small patch (as shown in [1]), can we have this updated in Debian
as soon as possible, before a new upstream version is uploaded to the
archive (which would, quite possibly need a new transition etc.)?


Thanks in advance,

Rogério.

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (500, 'testing'), (200, 'unstable'), (150, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.15.0-2-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.utf-8, LC_CTYPE=pt_BR.utf-8 (charmap=UTF-8), LANGUAGE=en_US.utf-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libpoppler-glib8 depends on:
ii  libc6         2.27-3
ii  libcairo2     1.15.10-1
ii  libfreetype6  2.8.1-2
ii  libglib2.0-0  2.56.0-4
ii  libpoppler73  0.62.0-2
ii  libstdc++6    8-20180402-1

libpoppler-glib8 recommends no packages.

libpoppler-glib8 suggests no packages.

-- no debconf information

-- 
Rogério Brito : rbrito@{ime.usp.br,gmail.com} : GPG key 4096R/BCFCAAAA
http://cynic.cc/blog/ : github.com/rbrito : profiles.google.com/rbrito
DebianQA: http://qa.debian.org/developer.php?login=rbrito%40ime.usp.br