Sorry, I should have explained that the bulk of my patch was derived from 
existing code.  The code that references fpos_t is basically a cut and 
paste of code from Modules/bz2module.c.  I don't know if this is a valid 
usage of fpos_t, but if it isn't, you should probably file a bug on the 
existing usage in bz2module and suggest a fix.  Thanks for reviewing!