Poppler packaging suggestion
dg1727
dg1727 at hushmail.com
Tue Aug 21 20:08:13 UTC 2012
Hello,
About Poppler, I have a packaging suggestion which may affect
Ubuntu installer code as well.
First some background:
In order to render CJK fonts in PDF files, Poppler needs the
package "poppler-data" to be installed. If "poppler-data" isn't
installed, any CJK text in a document is invisible.
It is stated in https://bugs.launchpad.net/ubuntu/+source/language-
selector/+bug/893920 that "poppler-data" shouldn't be a regular
(mandatory) dependency because "poppler-data" is too big to fit on
an Ubuntu install CD.
An intended solution has been made (documented in
https://bugs.launchpad.net/ubuntu/+source/language-
selector/+bug/893920 ) by modifying "language-selector", starting
with Ubuntu 12.04 LTS, to install poppler-data unconditionally.
There are some cases in which I think this intended solution might
not work:
A. I don't know much about language-selector, so I suppose there
may be cases when language-selector doesn't run, either on upgrade
from a version of Ubuntu prior to 12.04, or on a new install of
12.04 or higher.
B. As I recall, once the OS (12.04 or higher) is installed, a
notification icon prompts the user to run "language-selector", but
the user may ignore this notification. Until language-selector is
run, poppler-data doesn't get automatically installed.
C. Someone may un-install poppler-data, either accidentally or on
purpose, (if a PDF reader was un-installed as part of this, then
the same or a different PDF reader may then be re-installed without
poppler-data,) then try to view a PDF file that contains CJK fonts.
My idea is ...
... to make "poppler-data" a Recommended dependency of Poppler, and
that certain use cases will be as follows:
1. CD installs will enable the apt-get flag "--no-install-
recommends", so that APT won't try to install poppler-data from the
CD, since poppler-data won't be on the CD.
2. The existing installer has a prompt similar to "Do you want to
update all software to the latest versions via the Internet?".
When this is selected by the user and packages are being
downloaded, "--no-install-recommends" can be disabled (possibly
letting the user override this in case they are very low on disk
space), so that poppler-data will be downloaded and installed.
3. DVD installs can disable "--no-install-recommends", and have
poppler-data on the DVD. Poppler-data will be installed
unconditionally from the DVD, without the user being prompted,
without network access being needed, and without requiring the user
to run "language-selector" from the desktop notification.
4. The "--no-install-recommends" flag can be disabled by default
in the GUI frontends to APT (it may be already), so that in case C
above, poppler-data will automatically get re-installed along with
any PDF reader that uses poppler-data, unless the user has enabled
this flag.
As stated in
https://bugs.launchpad.net/ubuntu/+source/poppler/+bug/197537/commen
ts/7 :
(The bug summary is "Can't read PDF file with CJK
(Chinese/Japanese/Korean) text".)
"The fix should be somewhere in the poppler, it's not applicatin
task to care about cidToUnicode mask."
... so I am suggesting that poppler-data be made a dependency of
Poppler, not of a specific PDF-reading application.
I hope that labeling certain dependencies as Recommended, and
adjusting the "--no-install-recommends" strategy as suggested, may
be helpful in cases other than poppler-data, for packages that
users would generally want to have but that don't fit on an install
CD.
The issue of invisible "CJK" fonts can affect PDF documents that
contain only Latin characters but were produced by software that is
set up for CJK speakers. So the issue can affect non-CJK-speaking
users.
Thanks in advance for comment.
-dg1727
More information about the Ubuntu-devel-discuss
mailing list