[at-spi2-core] Optionally read the dbus address from env var AT_SPI_BUS_ADDRESS

[Mike Gorse <mgorse src gnome org>]

commit 0cce560e437e39daf04e0dd60b38f6c313c7112a
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Aug 31 17:06:13 2017 +0200

    Optionally read the dbus address from env var AT_SPI_BUS_ADDRESS
    
    This will be used for flatpak to set a custom bus (which is really
    the bus proxy). It can be used for testing purposes too.
    
    For more details, see https://github.com/flatpak/flatpak/issues/79
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787126

 atspi/atspi-misc.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/atspi/atspi-misc.c b/atspi/atspi-misc.c
index 46d1c11..eebbed4 100644
--- a/atspi/atspi-misc.c
+++ b/atspi/atspi-misc.c
@@ -1577,6 +1577,7 @@ atspi_get_a11y_bus (void)
 {
   DBusError error;
   char *address = NULL;
+  const char *address_env = NULL;
 
   if (a11y_bus && dbus_connection_get_is_connected (a11y_bus))
     return a11y_bus;
@@ -1585,8 +1586,12 @@ atspi_get_a11y_bus (void)
     if (!dbus_connection_allocate_data_slot (&a11y_dbus_slot))
       g_warning ("at-spi: Unable to allocate D-Bus slot");
 
+  address_env = g_getenv ("AT_SPI_BUS_ADDRESS");
+  if (address_env != NULL && *address_env != 0)
+    address = g_strdup (address_env);
 #ifdef HAVE_X11
-  address = get_accessibility_bus_address_x11 ();
+  if (!address)
+    address = get_accessibility_bus_address_x11 ();
 #endif
   if (!address)
     address = get_accessibility_bus_address_dbus ();