Merge ~osomon/ubiquity:impish-live-session-release-notes-1945658 into ubiquity:master

[Olivier Tilloy]

Also preserve XDG_DATA_DIRS when running ubiquity in a live session.

This fixes opening the release notes hyperlink (and all other hyperlinks)
with the correct application (firefox vs gedit) (LP: #1945658).

[Iain Lane (laney)]

👍

review: Approve

[Jean-Baptiste Lallement (jibel)]

Maybe move the sudo wrapper to misc.py. WDYT?

[Olivier Tilloy (osomon)]

Good suggestion. Done.

[Jean-Baptiste Lallement (jibel)]

Approved! thanks.

review: Approve

diff --git a/data/ubiquity.desktop.in b/data/ubiquity.desktop.in
index 691f802..3cb3434 100644
--- a/data/ubiquity.desktop.in
+++ b/data/ubiquity.desktop.in
@@ -6,7 +6,7 @@ _Name=Install RELEASE
 _Comment=Install this system permanently to your hard disk
 _Keywords=ubiquity;
 #use sh because pkexec is broken under xfce/lxce http://pad.lv/1193526
-Exec=sudo --preserve-env=DBUS_SESSION_BUS_ADDRESS,XDG_RUNTIME_DIR sh -c 'ubiquity gtk_ui'
+Exec=sudo --preserve-env=DBUS_SESSION_BUS_ADDRESS,XDG_DATA_DIRS,XDG_RUNTIME_DIR sh -c 'ubiquity gtk_ui'
 Icon=ubiquity
 Terminal=false
 Categories=GTK;System;Settings;
diff --git a/ubiquity/gsettings.py b/ubiquity/gsettings.py
index 7b1cced..d31d044 100644
--- a/ubiquity/gsettings.py
+++ b/ubiquity/gsettings.py
@@ -48,8 +48,7 @@ def get(schema, key, user=None):
         user = os.getenv("SUDO_USER", os.getenv("USER", "root"))
 
     subp = subprocess.Popen(
-        ['sudo', '--preserve-env=DBUS_SESSION_BUS_ADDRESS,XDG_RUNTIME_DIR',
-         '-H', '-u', user, 'gsettings', 'get', schema, key],
+        misc.sudo_wrapper(user) + ['gsettings', 'get', schema, key],
         stdout=subprocess.PIPE, stderr=subprocess.PIPE,
         preexec_fn=misc.drop_all_privileges, universal_newlines=True)
     value = subp.communicate()[0].rstrip('\n')
@@ -106,8 +105,8 @@ def set(schema, key, value, user=None):
         value = "true" if value else "false"
 
     subprocess.call(
-        ['sudo', '--preserve-env=DBUS_SESSION_BUS_ADDRESS,XDG_RUNTIME_DIR',
-         '-H', '-u', user, 'gsettings', 'set', schema, key, str(value)],
+        misc.sudo_wrapper(user) +
+        ['gsettings', 'set', schema, key, str(value)],
         preexec_fn=misc.drop_all_privileges)
 
 
@@ -127,6 +126,5 @@ def unset(schema, key, user=None):
         user = os.getenv("SUDO_USER", os.getenv("USER", "root"))
 
     subprocess.call(
-        ['sudo', '--preserve-env=DBUS_SESSION_BUS_ADDRESS,XDG_RUNTIME_DIR',
-         '-H', '-u', user, 'gsettings', 'reset', schema, key],
+        misc.sudo_wrapper(user) + ['gsettings', 'reset', schema, key],
         preexec_fn=misc.drop_all_privileges)
diff --git a/ubiquity/misc.py b/ubiquity/misc.py
index bc88d5d..7ff6629 100644
--- a/ubiquity/misc.py
+++ b/ubiquity/misc.py
@@ -1086,4 +1086,23 @@ class SystemdUnitWatcher:
                 raise
 
 
+def sudo_wrapper(user):
+    """Return a list of args suitable for use with the subprocess module,
+    to invoke a command as a given user, while preserving a set of useful
+    environment variables. Append the command and list of args to be invoked
+    to the return value of this helper.
+    """
+    preserve_env = [
+        'DBUS_SESSION_BUS_ADDRESS',
+        'XDG_DATA_DIRS',
+        'XDG_RUNTIME_DIR',
+    ]
+    return [
+        'sudo',
+        '--preserve-env={}'.format(','.join(preserve_env)),
+        '-H',
+        '-u', user
+    ]
+
+
 # vim:ai:et:sts=4:tw=80:sw=4: