What about more modern versions of findutils? This code is taken from gnulib and is included in quite a large number of GPLed software projects. Fixing it in gnulib will benefit a number of projects.
findutils v4.3.9 When _IOERR is defined, fpurge.c, freadahead.c, and freading.c wrongly assume FILE struct members are named with a single leading "_" character. E.g., this section of code at line 95
Hi, I've just run 'make check' for findutils-4.4.2 with results as follows: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ... cc -g -o test-canonicalize-