Subject: bug#19825: [bug-diffutils] bug#19825: unified output format, number of consecutive unaffected lines, and POSIX

From: Paul Eggert <[email-masked]>
Date: Mon, 09 Feb 2015 22:49:35 -0800

Vincent Lefevre wrote:
> Or could this be regarded as a defect in POSIX?

That's what I'd say, yes.  POSIX was intended to codify GNU diff's behavior 
here, and it seems to have missed the corner case you describe.