[Bricksmith] MPD file handling crash

[Travis Cobbs]

I did fail to put things into context in my previous post. The original LDView release (version 0.1) was in June of 2000. The first time anyone reported the circular reference crash to me was in July of 2007. The only other circular reference crash that has been reported to me (the MPD one) was reported in February of this year. So it does appear to be rare. The problem with the part example, though, is that if anyone has such a broken part, anything that causes your program to try to load that part (such as merely clicking on it in the parts list) will cause a crash.