Correct tests using std::string::find_XXX which did not use std::string::npos. * symtab.cc (find_function): For old-style class syntax, avoid setting method == dispatch if there is no dir_sep_str. * __osmesa_print__.cc: Correctly check for pipe command versus filename. * audioread.cc: Correctly find extension of file after '.'.

7f19e7f2afa2b1476983003f9cd6df2f5b2a4b08 gnulib-hg