Re: [PATCH] Revert 'diff-merges: let "-m" imply "-p"'

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Aug 7, 2021, 01:55 UTC
Message-ID: <YQ3n9Z2nH35429mC@google.com>
In-Reply-To: <xmqqh7g2ij5q.fsf@gitster.g>

Hi,

Junio C Hamano wrote:

Show 5 quoted lines

> I am somewhat puzzled.  What does "can imagine" exactly mean and
> justify this change?  A script author may imagine "git cat-file" can
> be expected to meow, but the command actually does not meow and end
> up disappointing the author, but that wouldn't justify a rename of
> "cat-file" to something else.

Sorry for the lack of clarity. I was describing what leads a script author to include "-m" in a place where it has no effect.

You might be inclined to wonder why it matters _why_ a script author would do such a thing, if the script author is wrong. To me, it matters because it allows us to estimate how common it is for scripts to use "-m" in this way.

The motivating example (Rust) shows that there is at least one script that _did_ use "-m" in this way. Rust has mitigation, but the above logic leads me to believe that they are not the only project that will be affected. And more generally, when a script author has a reasonable reason to believe something will work, they write scripts where it _does_ work, and then an update breaks their script, I think it's reasonable for them not to be happy.

Jonathan