[Pkg-utopia-maintainers] Bug#668225: colord-sane thread-safety in wheezy

[Simon McVittie]

# let's have some version-tracking
reassign 668225 colord
found 668225 0.1.18-1
found 668225 0.1.21-1
fixed 668225 0.1.31-1
thanks

Please use a Subject line that summarizes the subject of the email. I
received "Subject: Bug#668225: Wheezy" talking about an unspecified bug
out-of-context, and had to look up the bug report in order to have any
idea what you were talking about :-)

On 16/05/13 07:00, Christian Kastner wrote:
> Would it be possible to include [a fix for libdbus-related
> thread-safety problems in colord] in the next Wheezy point
> release (7.0.1)?

I suspect the necessary changes to be rather too large for a stable
update, given that the changelog describes it as a "rewrite". However, a
necessary first step would be for people who reliably get this crash to
confirm that 0.1.31 actually fixes it.

It looks as though a less intrusive fix for wheezy might be to drop the
"full" SANE plugin and instead backport the udev-based cd-plugin-scanner
module added by commit ebf3e961, which can detect local scanners but not
networked ones:

+# If we should use SANE to add scanner and camera devices.
+#
+# If SANE support is installed then this will allow colord to manage
+# all scanners that SANE can detect, including remote scanners.
+#
+# If this is disabled then colord will only detect locally connected
+# scanners.

Another possibility for a "lightweight" workaround would be to set
UseSANE to false in the default configuration file, which would result
in colour correction for screens and printers but not scanners.

I haven't had any response to the upstream libsane bug I opened querying
some code used by colord-sane that uses threads but does not look
thread-safe
(<https://alioth.debian.org/tracker/index.php?func=detail&aid=313921&group_id=30186&atid=410366>).

Adding a call to dbus_threads_init_default() early in colord-sane's
main() can't hurt, either.

> I'd categorize a process that segfaults at boot with a severity
> of at least "important"

I would say that depends what that process does, and what effect the
crash has. If a process crashes in the forest where nobody can hear it,
did it make a sound? :-)

    S