[bug-diffutils] bug#27241: bug#27241: diff command modified my file

[Paul Eggert]

Hong Jehn wrote:
> When I use command "diff -qr abc/ usb/abc/" to compare 2 directory,  it changes the 
> "centos_7_x86_64_Minimal.iso" sometime but the file size didn't change even when I just 
> ran the same command and it says they are the same. Other file are fine, it changes only this iso 
> file.
>
> Also, I wrote a similler program like diff before it came out the same problem. 
> I guess it's a glibc bug? I kept the broken file in case you need it.
>
> This problem comes out like once a week, I kept the sha256-code but this 
> problem seems serious.

Since the problem affects multiple programs, it must be something else in your 
system, either in the C library or (more likely) in the underlying file system 
code or something like that.