Re: [PATCH 2/2] diff: fix --exit-code with external diff

From: Phillip Wood <phillip.wood123@gmail.com>
Date: May 5, 2024, 15:25 UTC
Message-ID: <99337bc2-a691-45f7-9b6f-74ededbd9a78@gmail.com>
In-Reply-To: <e2e4a4e9-55db-403c-902d-fd8af3aea05c@web.de>

Hi René

Thanks for working on this

On 05/05/2024 11:20, René Scharfe wrote:

> Finally, capture the output of the external diff and only register a
> change by setting found_changes if the program wrote anything.

I worry that this will lead to regression reports like https://lore.kernel.org/git/CA+dzEBn108QoMA28f0nC8K21XT+Afua0V2Qv8XkR8rAeqUCCZw@mail.gmail.com/ as the external diff will not see a terminal on stdout anymore. I'm not really clear why we ignore the exit code of the external diff command. Merge strategies are expected to exit 0 on success, 1 when there are conflicts and another non-zero value for other errors - it would be nice to do something similar here where 1 means "there were differences" but it is probably too late to do that without a config value to indicate that we should trust the exit code.

Best Wishes

Phillip