diff alias which used to work in version 2.27, failing from version 2.28 onwards

From: Reverdell Auriane <auriane.reverdell@cscs.ch>
Date: Aug 24, 2023, 10:19 UTC
Message-ID: <31866645d2ac4cb1be17e35fae742cb2@cscs.ch>

Hi,

To output the diff of a specific commit, I created the alias dici (see below), git dici 12345 or git dici to output the diff of the HEAD:

[alias]
    dici = !git diff ${1:-HEAD}^..${1:-HEAD}

a trace for this alias gives (same trace for both git 2.27 and 2.28!):

14:38:45.275964 git.c:439               trace: built-in: git diff a2028e7b^..a2028e7b a2028e7b

The commit number is put again at the end of the command (the wanted alias is supposed to output only `git diff a2028e7b^..a2028e7b`), this was accepted by version 2.27 but not by the version 2.28. For now, my temporary fix is adding a bash comment at the end of the alias:

[alias]
    dici = "!git diff ${1:-HEAD}^..${1:-HEAD} #"

Note: the first alias still doesn't work with the latest git versions (tested with 2.40.0, 2.39.2, 2.37.5).

Is that expected behavior? if yes, how is the right/clean way to discard the command line argument of the alias?

Thanks in advance!

Auriane