[gnome-settings-daemon] Don't override preset xim setups

[Dominique Leuenberger <dleuen src gnome org>]

commit 21a16d25d981f3ce34b764dbc8005dbf8edfbe97
Author: Takashi Iwai <tiwai suse de>
Date:   Fri Oct 23 13:50:48 2015 +0200

    Don't override preset xim setups
    
    When $QT_IM_MODULE or $XMODIFIERS has been already set beforehand,
    we should honor it and not override brutally.  This makes GNOME as
    a good citizen coping with other IMs more smoothly.
    
    Signed-off-by: Takashi Iwai <tiwai suse de>

 .../gnome-settings-daemon-localeexec.in            |    4 ++--
 gnome-settings-daemon/main.c                       |   11 +++++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/gnome-settings-daemon/gnome-settings-daemon-localeexec.in 
b/gnome-settings-daemon/gnome-settings-daemon-localeexec.in
index eed91a4..1edb3d2 100755
--- a/gnome-settings-daemon/gnome-settings-daemon-localeexec.in
+++ b/gnome-settings-daemon/gnome-settings-daemon-localeexec.in
@@ -13,8 +13,8 @@ if [ -n "$REGION" ]; then
 fi
 
 if [ -x @prefix@/bin/ibus-daemon ]; then
-  export QT_IM_MODULE=ibus
-  export XMODIFIERS= im=ibus
+  test -z "$QT_IM_MODULE" && export QT_IM_MODULE=ibus
+  test -z "$XMODIFIERS" && export XMODIFIERS= im=ibus
 fi
 
 exec @libexecdir@/gnome-settings-daemon
diff --git a/gnome-settings-daemon/main.c b/gnome-settings-daemon/main.c
index 4d1140b..48d4bad 100644
--- a/gnome-settings-daemon/main.c
+++ b/gnome-settings-daemon/main.c
@@ -255,9 +255,16 @@ is_program_in_path (const char *binary)
 static void
 set_legacy_ibus_env_vars (GDBusProxy *proxy)
 {
+       const char *p;
         if (is_program_in_path ("ibus-daemon")) {
-                set_session_env (proxy, "QT_IM_MODULE", "ibus");
-                set_session_env (proxy, "XMODIFIERS", "@im=ibus");
+                p = getenv ("QT_IM_MODULE");
+                if (!p || !*p)
+                        p = "ibus";
+                set_session_env (proxy, "QT_IM_MODULE", p);
+                p = getenv ("XMODIFIERS");
+                if (!p || !*p)
+                        p = "@im=ibus";
+                set_session_env (proxy, "XMODIFIERS", p);
         }
 }