[$] C, Fortran, and single-character strings

The calling interfaces between programming languages are, by their nature,ripe for misunderstandings; different languages can have subtly differentideas of how data should be passed around. Such misunderstandings oftenhave the effect of making things break right away; these are quicklyfixed. Others can persist for years or even decades before jumping out ofthe shadows and making things fail. A problem of the latter varietyrecently turned up in how some C programs are passing strings to Fortransubroutines, with unpleasant effects on widely used packages like LAPACK.