Created attachment 275160 [details] [diff] [review] patch There is a problem where a nsString in the core is smaller than the nsString we get from nsStringAPI.h by 4 bytes. You can see this by comparing nsTSubstring_CharT with nsStringContainer_base. This is causing a problem for c++ extensions trying to work with libxul (in my case, xforms). They need to be the same size. bsmedberg said that we should be able to remove one of the void*'s from the front of nsStringContainer_base. That is what this patch will do. I tested the patch and it fixes my XForms crash.
checked into trunk