[bug-diffutils] bug#24629: bug#24629: Make unified diff configurable default

[Norbert Kiesel]

Patch was dead simple, so I just created it just in case.

On Thu, Oct 6, 2016 at 2:46 PM, Norbert Kiesel <address@hidden> wrote:

I like the two-step approach.  And this is clearly a feature that does not need to be rushed.  You want me to send a patch for step#1?

On Thu, Oct 6, 2016 at 1:19 PM, Paul Eggert <address@hidden> wrote:

On 10/06/2016 12:48 PM, Norbert Kiesel wrote:

But we should be able to support a GNU_DIFF_FORMAT environment
variable that sets the default format, no?

It might be a good idea to change the default output format. I expect the first step would be to change 'diff' to warn on stderr if no output format option is specified; you could silence the warning with the --normal option, or by setting POSIXLY_CORRECT. This step should also document the first step (and the intent to change the default) in the usual places. After some time in some later release we could then change the default.

I'd rather not have diff's behavior depend on a new environment variable. Environment variables are a pain to get right and something like this could break security-relevant code.

unified_as_default.diff
Description: Text document