[Bug-gsl] division by zero in gsl_sf_legendre_sphPlm_e

[alberto]

Hi,

[Regarding gsl-1.8]

When using a compiler with a division by zero trap, I have found
a *possible* bug in gsl_sf_legendre_sphPlm_e function, in legendre_poly.c
file.

The line where the error occurs is 575:

result->err += fabs(y_mm_err/y_mm) * fabs(y_ell)

Since I need to compile with these checks enabled, I have substituted it
by:

if(fabs(y_mm)>GSL_DBL_EPSILON) result->err += fabs(y_mm_err/y_mm) *
   fabs(y_ell);

which seems to work. But I am not sure if it is the proper solution, I
have no experience looking in the insides of gsl.

Alberto.