Index: plugins/mouse_plugin/mouse_plugin.c
===================================================================
--- plugins/mouse_plugin/mouse_plugin.c (revision 26490)
+++ plugins/mouse_plugin/mouse_plugin.c (working copy)
@@ -174,7 +174,7 @@ set_xinput_mouse_values (gboolean right_
     unsigned char *buttons;
     gint n_buttons, n_devices, i;
     gint idx_1 = 0, idx_3 = 1;
-    gsize buttons_capacity = 16;
+    gsize buttons_capacity = DEFAULT_PTR_MAP_SIZE;

     device_info = XListInputDevices (GDK_DISPLAY (), &n_devices);

@@ -204,11 +204,12 @@ set_xinput_mouse_values (gboolean right_
             continue;
         }

-        n_buttons = XGetDeviceButtonMapping (GDK_DISPLAY (), device, buttons, DEFAULT_PTR_MAP_SIZE);
-        if (n_buttons > DEFAULT_PTR_MAP_SIZE)
+        n_buttons = XGetDeviceButtonMapping (GDK_DISPLAY (), device, buttons, buttons_capacity);
+        if (n_buttons > buttons_capacity)
         {
-            buttons = g_alloca (n_buttons);
-            n_buttons = XGetDeviceButtonMapping (GDK_DISPLAY (), device, buttons, n_buttons);
+            buttons = g_realloc (buttons, n_buttons);
+            buttons_capacity = n_buttons;
+            n_buttons = XGetDeviceButtonMapping (GDK_DISPLAY (), device, buttons, buttons_capacity);
         }

         for (i = 0; i < n_buttons; i++)