Upstart sets D-Bus activation environment incorrectly if variable's value contains an "=" (was: $XMODIFIERS not set correctly)

[Gunnar Hjalmarsson]

When "initctl set-env -g" is called, upstart calls D-Bus to also update its activation environment (the environment that D-Bus activated services get). There is a bug here:

  - SetEnv takes a parameter of the form "VARIABLE=VALUE"
  - This is split on "=" to determine the two parts
  - If the VALUE has an "=" character in it, everything after the first "=" is lost, because all "=" characters are split and not the first one

In this case, XMODIFIERS=@im=ibus was being turned into XMODIFIERS=@im.

upstart should only split on the first "=", and keep the rest of the string unsplit. It doesn't look like nih_str_split is going to be very helpful here.

[ Original description ]

The XMODIFIERS environment variable is not set correctly.

$ echo $XMODIFIERS
@im
$

The value should be
- for ibus: "@im=ibus"
- for fcitx: "@im=fcitx"
- for xim: "@im=none"

The issue is present in Ubuntu/Unity 16.10. I don't see it in Ubuntu GNOME, neither in Ubuntu 16.04.

Actually I don't think the affected package is im-config, because the issue is present also after having downgraded im-config to 0.29-1ubuntu12 (the Xenial version). But I wanted to file the bug somewhere, so here it is.

[Martin Pitt (pitti)]

I don't think it's a quoting issue (or issue with parsing the extra '=') in d-u-a-e, as when I run this manually it works:

$ export XMODIFIERS=@im=ibus

$ dbus-update-activation-environment --verbose --systemd XMODIFIERS
dbus-update-activation-environment: setting XMODIFIERS=@im=ibus

$ systemctl --user show-environment |grep XMODIF
XMODIFIERS=@im=ibus

But clearly in a freshly started desktop the value is just "@im". My buest guess is that something else also sets $XMODIFIERS later on, and overwrites the value from im-config.service?

[Iain Lane (laney)]

From ExecStart of im-config.service (modified slightly to eliminate quoting issues)

Oct 04 10:09:43 yakkety-vm sh[1925]: + dbus-update-activation-environment --verbose --systemd XMODIFIERS
Oct 04 10:09:43 yakkety-vm sh[1925]: dbus-update-activation-environment: setting XMODIFIERS=@im=ibus

and then I added to the bottom of the same ExecStart:

Oct 04 10:09:43 yakkety-vm sh[1925]: + systemctl --user show-environment
[…]
Oct 04 10:09:43 yakkety-vm sh[1925]: XMODIFIERS=@im

So it does *not* seem to be a problem with overwriting to me.

[Iain Lane (laney)]

Now I modified each iteration of the loop in im-config.service to show the environment

Oct 04 10:21:20 yakkety-vm sh[1972]: + dbus-update-activation-environment --verbose --systemd XMODIFIERS
Oct 04 10:21:20 yakkety-vm sh[1972]: dbus-update-activation-environment: setting XMODIFIERS=@im=ibus
Oct 04 10:21:20 yakkety-vm sh[1972]: + systemctl --user show-environment
[…]
Oct 04 10:21:20 yakkety-vm sh[1972]: XMODIFIERS=@im=ibus

Oct 04 10:21:20 yakkety-vm sh[1972]: + dbus-update-activation-environment --verbose --systemd GTK_IM_MODULE
Oct 04 10:21:20 yakkety-vm sh[1972]: dbus-update-activation-environment: setting GTK_IM_MODULE=ibus
Oct 04 10:21:20 yakkety-vm sh[1972]: + systemctl --user show-environment
Oct 04 10:21:20 yakkety-vm sh[1972]: XMODIFIERS=@im

...

[Iain Lane (laney)]

The following is from

            dbus-update-activation-environment --verbose --systemd $$v; \
            systemctl --user show-environment | grep XMODIFIERS; \
            initctl set-env -gr $$v=$$(eval "echo \\$$$${v}") || true; \
            systemctl --user show-environment | grep XMODIFIERS; \

Oct 04 10:34:56 yakkety-vm sh[1960]: + dbus-update-activation-environment --verbose --systemd XMODIFIERS
Oct 04 10:34:56 yakkety-vm sh[1960]: dbus-update-activation-environment: setting XMODIFIERS=@im=ibus
Oct 04 10:34:56 yakkety-vm sh[1960]: + grep XMODIFIERS
Oct 04 10:34:56 yakkety-vm sh[1960]: + systemctl --user show-environment
Oct 04 10:34:56 yakkety-vm sh[1960]: XMODIFIERS=@im=ibus
Oct 04 10:34:56 yakkety-vm sh[1960]: + eval echo $XMODIFIERS
Oct 04 10:34:56 yakkety-vm sh[1960]: + echo @im=ibus
Oct 04 10:34:56 yakkety-vm sh[1960]: + initctl set-env -gr XMODIFIERS=@im=ibus
Oct 04 10:34:56 yakkety-vm sh[1960]: + systemctl --user show-environment
Oct 04 10:34:56 yakkety-vm sh[1960]: + grep XMODIFIERS
Oct 04 10:34:56 yakkety-vm sh[1960]: XMODIFIERS=@im

What is shows is that the value of XMODIFIERS in "systemctl --user show-environment" changes after "initctl set-env -gr $$v=$$(eval "echo \\$$$${v}") || true;" is run

[Iain Lane (laney)]

I think it's upstart being buggy when forwarding the initctl set-env -g to the dbus activation environment

‣ Type=method_call Endian=l Flags=0 Version=1 Priority=0 Cookie=5665
  Sender=:1.15 Destination=org.freedesktop.DBus Path=/org/freedesktop/DBus Interface=org.freedesktop.DBus Member=UpdateActivationEnvironment
  UniqueName=:1.15
  MESSAGE "a{ss}" {
          ARRAY "{ss}" {
                  DICT_ENTRY "ss" {
                          STRING "FOO";
                          STRING "bar";
                  };
          };
  };

[Iain Lane (laney)]

That was from "initctl set-env FOO=bar=baz"

[Iain Lane (laney)]

sorry, initctl set-env -g

[Iain Lane (laney)]

Just updated the description. The problem is now understood, and we worked around the upstart bug in gnome-session and im-config.

[Launchpad Janitor (janitor)]

This bug was fixed in the package im-config - 0.29-1ubuntu16

---------------
im-config (0.29-1ubuntu16) yakkety; urgency=medium

  * debian/user/im-config.service: Reverse the order of "initctl set-env" and
    "dbus-update-activation-environment". $XMODIFIERS can contain an "=" (its
    value might be, for example, "@im=ibus"). upstart forwards "set-env -g"
    calls to D-Bus, but it constructs the parameters to the call incorrectly
    and splits on "=" characters in the value, discarding anything which
    follows. We can work around this bug by calling "initctl set-env -g"
    first, and then "dbus-update-activation-environment" to overwrite the
    buggy value. (LP: #1630090)
  * debian/user/im-config.service: Get rid of one eval -
    "dbus-update-activation-environment" will look up the variable in the
    environment if you don't specify a value.

 -- Iain Lane <email address hidden> Tue, 04 Oct 2016 12:28:35 +0100

[Gunnar Hjalmarsson (gunnarhj)]

Can confirm that XMODIFIERS is set correctly with the latest versions of the im-config and gnome-session-* packages. Thanks for a quick workaround. :)