[vala/wip/bug778540: 2/2] dbus: Account for _reply_message being NULL in error paths

[Rico Tzschichholz <ricotz src gnome org>]

commit f0cec6a38b8350171f374add3448133fb9c5b734
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Feb 18 15:27:13 2017 +0100

    dbus: Account for _reply_message being NULL in error paths
    
    Commit 09e6818d01 changed dbus server paths so requests fell back
    to freeing allocated memory on errors. However certain kinds of
    dbus replies issue a final g_dbus_connection_send_message() there.
    
    In case of errors, _reply_message will be NULL, and the error paths
    would have already issued g_dbus_method_invocation_return_gerror(),
    so the g_dbus_connection_send_message() call is both unnecessary and
    warns on the NULL argument. So add a NULL check for these cases.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778540

 codegen/valagdbusservermodule.vala |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/codegen/valagdbusservermodule.vala b/codegen/valagdbusservermodule.vala
index e3cbc6e..a51e701 100644
--- a/codegen/valagdbusservermodule.vala
+++ b/codegen/valagdbusservermodule.vala
@@ -369,9 +369,13 @@ public class Vala.GDBusServerModule : GDBusClientModule {
                }
 
                if (!no_reply && (!m.coroutine || ready)) {
+                       var reply_message = new CCodeIdentifier ("_reply_message");
+                       var expr = new CCodeBinaryExpression (CCodeBinaryOperator.INEQUALITY, reply_message, 
new CCodeConstant ("NULL"));
+                       ccode.open_if (expr);
+
                        var return_value = new CCodeFunctionCall (new CCodeIdentifier 
("g_dbus_connection_send_message"));
                        return_value.add_argument (connection);
-                       return_value.add_argument (new CCodeIdentifier ("_reply_message"));
+                       return_value.add_argument (reply_message);
                        return_value.add_argument (new CCodeConstant ("G_DBUS_SEND_MESSAGE_FLAGS_NONE"));
                        return_value.add_argument (new CCodeConstant ("NULL"));
                        return_value.add_argument (new CCodeConstant ("NULL"));
@@ -383,8 +387,10 @@ public class Vala.GDBusServerModule : GDBusClientModule {
                        ccode.add_expression (unref_call);
 
                        unref_call = new CCodeFunctionCall (new CCodeIdentifier ("g_object_unref"));
-                       unref_call.add_argument (new CCodeIdentifier ("_reply_message"));
+                       unref_call.add_argument (reply_message);
                        ccode.add_expression (unref_call);
+
+                       ccode.close ();
                }
 
                pop_function ();