[vala/0.34] gdbus: Handle errors when extracting fds from dbus messages

[Rico Tzschichholz <ricotz src gnome org>]

commit b5c57df05f075a87f43e97091ea3b10b5dc69b7f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Feb 12 23:10:05 2017 +0100

    gdbus: Handle errors when extracting fds from dbus messages
    
    On the right situations (eg. fd exhaustion), both
    g_dbus_message_get_unix_fd_list() and g_unix_fd_list_get() should be
    considered failable here. Add proper error handling to avoid triggering
    glib warnings.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778540

 codegen/valagdbusclientmodule.vala |    3 ++-
 codegen/valagdbusmodule.vala       |   33 +++++++++++++++++++++++++++------
 codegen/valagdbusservermodule.vala |    3 ++-
 3 files changed, 31 insertions(+), 8 deletions(-)
---
diff --git a/codegen/valagdbusclientmodule.vala b/codegen/valagdbusclientmodule.vala
index 483264d..e1a53fb 100644
--- a/codegen/valagdbusclientmodule.vala
+++ b/codegen/valagdbusclientmodule.vala
@@ -615,7 +615,6 @@ public class Vala.GDBusClientModule : GDBusModule {
                        ccode.add_expression (builder_init);
 
                        if (uses_fd) {
-                               ccode.add_declaration ("GUnixFDList", new CCodeVariableDeclarator 
("*_fd_list"));
                                ccode.add_assignment (new CCodeIdentifier ("_fd_list"), new CCodeFunctionCall 
(new CCodeIdentifier ("g_unix_fd_list_new")));
                        }
 
@@ -751,6 +750,8 @@ public class Vala.GDBusClientModule : GDBusModule {
 
                        if (uses_fd) {
                                ccode.add_declaration ("gint", new CCodeVariableDeclarator.zero ("_fd_index", 
new CCodeConstant ("0")));
+                               ccode.add_declaration ("GUnixFDList*", new CCodeVariableDeclarator 
("_fd_list"));
+                               ccode.add_declaration ("gint", new CCodeVariableDeclarator ("_fd"));
                        }
 
                        foreach (Parameter param in m.get_parameters ()) {
diff --git a/codegen/valagdbusmodule.vala b/codegen/valagdbusmodule.vala
index 8f10daa..0a6404a 100644
--- a/codegen/valagdbusmodule.vala
+++ b/codegen/valagdbusmodule.vala
@@ -220,21 +220,42 @@ public class Vala.GDBusModule : GVariantModule {
                var fd_list = new CCodeFunctionCall (new CCodeIdentifier ("g_dbus_message_get_unix_fd_list"));
                fd_list.add_argument (message_expr);
 
-               var fd = new CCodeFunctionCall (new CCodeIdentifier ("g_unix_fd_list_get"));
-               fd.add_argument (fd_list);
-               fd.add_argument (new CCodeIdentifier ("_fd_index"));
-               fd.add_argument (new CCodeConstant ("NULL"));
+               var fd_var = new CCodeIdentifier ("_fd");
 
-               var stream = create_from_file_descriptor (type, fd);
+               var stream = create_from_file_descriptor (type, fd_var);
                if (stream != null) {
+                       var fd_list_var = new CCodeIdentifier ("_fd_list");
+
+                       var fd = new CCodeFunctionCall (new CCodeIdentifier ("g_unix_fd_list_get"));
+                       fd.add_argument (fd_list_var);
+                       fd.add_argument (new CCodeIdentifier ("_fd_index"));
+                       fd.add_argument (error_expr);
+
+                       ccode.add_assignment (fd_list_var, fd_list);
+                       ccode.open_if (fd_list_var);
+
                        var get_fd = new CCodeFunctionCall (new CCodeIdentifier ("g_variant_iter_next"));
                        get_fd.add_argument (new CCodeUnaryExpression (CCodeUnaryOperator.ADDRESS_OF, 
iter_expr));
                        get_fd.add_argument (new CCodeConstant ("\"h\""));
                        get_fd.add_argument (new CCodeUnaryExpression (CCodeUnaryOperator.ADDRESS_OF, new 
CCodeIdentifier ("_fd_index")));
                        ccode.add_expression (get_fd);
 
+                       ccode.add_assignment (fd_var, fd);
+                       ccode.open_if (new CCodeBinaryExpression (CCodeBinaryOperator.GREATER_THAN_OR_EQUAL, 
fd_var, new CCodeConstant ("0")));
+
                        ccode.add_assignment (target_expr, stream);
-                       may_fail = false;
+                       may_fail = true;
+
+                       ccode.close ();
+
+                       ccode.add_else ();
+                       var set_error = new CCodeFunctionCall (new CCodeIdentifier ("g_set_error_literal"));
+                       set_error.add_argument (error_expr);
+                       set_error.add_argument (new CCodeIdentifier ("G_IO_ERROR"));
+                       set_error.add_argument (new CCodeIdentifier ("G_IO_ERROR_FAILED"));
+                       set_error.add_argument (new CCodeConstant ("\"FD List is NULL\""));
+                       ccode.add_expression (set_error);
+                       ccode.close ();
                } else {
                        read_expression (type, iter_expr, target_expr, sym, error_expr, out may_fail);
                }
diff --git a/codegen/valagdbusservermodule.vala b/codegen/valagdbusservermodule.vala
index b7592df..56b7657 100644
--- a/codegen/valagdbusservermodule.vala
+++ b/codegen/valagdbusservermodule.vala
@@ -62,6 +62,7 @@ public class Vala.GDBusServerModule : GDBusClientModule {
                bool uses_fd = dbus_method_uses_file_descriptor (m);
                if (uses_fd) {
                        cfile.add_include ("gio/gunixfdlist.h");
+                       ccode.add_declaration ("GUnixFDList*", new CCodeVariableDeclarator ("_fd_list"));
                }
 
                bool uses_error = false;
@@ -93,6 +94,7 @@ public class Vala.GDBusServerModule : GDBusClientModule {
                if (!ready) {
                        if (uses_fd) {
                                ccode.add_declaration ("gint", new CCodeVariableDeclarator.zero ("_fd_index", 
new CCodeConstant ("0")));
+                               ccode.add_declaration ("gint", new CCodeVariableDeclarator ("_fd"));
                        }
 
                        foreach (Parameter param in m.get_parameters ()) {
@@ -257,7 +259,6 @@ public class Vala.GDBusServerModule : GDBusClientModule {
                        ccode.add_expression (builder_init);
 
                        if (uses_fd) {
-                               ccode.add_declaration ("GUnixFDList", new CCodeVariableDeclarator 
("*_fd_list"));
                                ccode.add_assignment (new CCodeIdentifier ("_fd_list"), new CCodeFunctionCall 
(new CCodeIdentifier ("g_unix_fd_list_new")));
                        }