Continuing the discussion of
http://sourceware.org/ml/gsl-discuss/2007-q4/msg00038.html :

Two files with the "diff -u" format are attached
which implement Gaussian Hypergeometric Functions 2F1() for argument x=1.
The implementation in hyperg_2F1.c has been changed to handle cases
with negative values of the intermediate Gamma-functions correctly.

All 4 tests added to test_hyperg.c are passed on my gcc 4.1.2 (i386 RedHat).

On an unrelated issue, the testing for some 2F0() has been improved by
insertion of more accurate results in test_hyperg.c.

-- 
Richard J Mathar
http://www.strw.leidenuniv.nl/~mathar