Hi Duy,

On Wed, 3 May 2017, Nguyễn Thái Ngọc Duy wrote:

> This code uses the result FILE pointer right away without the NULL
> check. Let's use xfopen() and die if we could not open the file. That's
> still better than crashing,
> 
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

While funny to read, maybe it would be better to spell it out clearly:

	copy_alternates() called fopen() without handling errors. By
	switching to xfopen(), this bug is fixed.

Ciao,
Dscho