[gnome-software] GsApp: Fix a possible race and crash when loading icons

[Kalev Lember <klember src gnome org>]

commit 0cbc93fb9206c35dbd8508f7e1a3fd2476fb861f
Author: Kalev Lember <klember redhat com>
Date:   Wed Jun 24 16:38:01 2015 +0200

    GsApp: Fix a possible race and crash when loading icons
    
    Use our private icon theme instance in gs_app_get_pixbuf() and add
    locking to make sure the access to the icon theme is serialized.
    GtkIconTheme is not thread safe and we need to make sure the UI thread
    and the plugin threads don't access it simultaneously.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1176017

 src/gs-app.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/src/gs-app.c b/src/gs-app.c
index 1350845..348ef83 100644
--- a/src/gs-app.c
+++ b/src/gs-app.c
@@ -869,11 +869,12 @@ gs_app_get_pixbuf (GsApp *app)
 {
        g_return_val_if_fail (GS_IS_APP (app), NULL);
 
+       g_mutex_lock (&icon_theme_lock);
        /* has an icon */
        if (APP_PRIV (app)->pixbuf == NULL &&
            APP_PRIV (app)->icon != NULL &&
            as_icon_get_kind (APP_PRIV (app)->icon) == AS_ICON_KIND_STOCK) {
-               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
+               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (icon_theme_get (),
                                                              as_icon_get_name (APP_PRIV (app)->icon), 64,
                                                              GTK_ICON_LOOKUP_USE_BUILTIN |
                                                              GTK_ICON_LOOKUP_FORCE_SIZE,
@@ -887,31 +888,32 @@ gs_app_get_pixbuf (GsApp *app)
                        icon_name = "application-x-addon";
                else
                        icon_name = "application-x-executable";
-               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
+               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (icon_theme_get (),
                                                              icon_name, 96,
                                                              GTK_ICON_LOOKUP_USE_BUILTIN |
                                                              GTK_ICON_LOOKUP_FORCE_SIZE,
                                                              NULL);
 
        } else if (APP_PRIV (app)->pixbuf == NULL && gs_app_get_kind (app) == GS_APP_KIND_PACKAGE) {
-               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
+               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (icon_theme_get (),
                                                              "application-x-addon", 64,
                                                              GTK_ICON_LOOKUP_USE_BUILTIN |
                                                              GTK_ICON_LOOKUP_FORCE_SIZE,
                                                              NULL);
        } else if (APP_PRIV (app)->pixbuf == NULL && gs_app_get_kind (app) == GS_APP_KIND_OS_UPDATE) {
-               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
+               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (icon_theme_get (),
                                                              "software-update-available-symbolic", 64,
                                                              GTK_ICON_LOOKUP_USE_BUILTIN |
                                                              GTK_ICON_LOOKUP_FORCE_SIZE,
                                                              NULL);
        } else if (APP_PRIV (app)->pixbuf == NULL && gs_app_get_kind (app) == GS_APP_KIND_MISSING) {
-               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (),
+               APP_PRIV (app)->pixbuf = gtk_icon_theme_load_icon (icon_theme_get (),
                                                              "dialog-question-symbolic", 16,
                                                              GTK_ICON_LOOKUP_USE_BUILTIN |
                                                              GTK_ICON_LOOKUP_FORCE_SIZE,
                                                              NULL);
        }
+       g_mutex_unlock (&icon_theme_lock);
 
        return APP_PRIV (app)->pixbuf;
 }