The main cause here were the wrong style classes being removed, such as
"message-dialog" instead of "csd" for GtkMessageDialog.
if ((*decl)->refcount == 1)
{
if (bytes_removed > 0 && old_size - offset - bytes_removed > 0)
- memmove (((char *) *decl) + offset + bytes_removed, ((char *) *decl) + offset, old_size - offset - bytes_removed);
+ memmove (((char *) *decl) + offset, ((char *) *decl) + offset + bytes_removed, old_size - offset - bytes_removed);
*decl = g_realloc (*decl, new_size);
if (bytes_added > 0 && old_size - offset > 0)
memmove (((char *) *decl) + offset + bytes_added, ((char *) *decl) + offset, old_size - offset);