@param fp BGZF file handle
@param idx hFILE to read from
@param name file name (for error reporting only; can be NULL)
@return 0 on success and -1 on error.
Populates @p fp with index data read from the hFILE handle @p idx.
The file pointer to @idx should point to the start of the index
data when this function is called.
The file name can optionally be passed in the @p name parameter. This
is only used for printing error messages; if NULL the word "index" is
used instead.
@param fp BGZF file handle @param idx hFILE to read from @param name file name (for error reporting only; can be NULL) @return 0 on success and -1 on error.
Populates @p fp with index data read from the hFILE handle @p idx. The file pointer to @idx should point to the start of the index data when this function is called.
The file name can optionally be passed in the @p name parameter. This is only used for printing error messages; if NULL the word "index" is used instead.