Re: [PATCH 1/2] restore: require --source when combining --worktree and --staged

> The default restore source for --worktree is the index, and the default
> source for --staged is HEAD. When combining --worktree and --staged in
> the same invocation, the restore source is ambiguous ("should it restore
> from the index or from HEAD?"). To avoid such ambiguity, the git-restore
> documentation has always stated that --source must be used when
> combining --worktree and --staged. However, this restriction is not
> actually enforced. Address this deficiency by making the implementation
> match the documented behavior (to wit, error out if --source is not
> specified when combining --worktree and --staged).

> While at it, enhance the documentation to mention the --source
> requirement prominently in the "Description" section (rather than only
> in the description of the --source option itself).
>
> Reported-by: Harri Mehtälä <harri.mehtala@finago.com>
> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
> ---
>  Documentation/git-restore.txt | 3 ++-
>  builtin/checkout.c            | 3 +++
>  t/t2070-restore.sh            | 5 +++++
>  3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/git-restore.txt b/Documentation/git-restore.txt
> index 8e3b339802..8906499637 100644
> --- a/Documentation/git-restore.txt
> +++ b/Documentation/git-restore.txt
> @@ -24,7 +24,8 @@ The command can also be used to restore the content in the index with
>
>  By default, the restore sources for working tree and the index are the
>  index and `HEAD` respectively. `--source` could be used to specify a
> -commit as the restore source.
> +commit as the restore source; it is required when combining `--staged`
> +and `--worktree`.
>
>  See "Reset, restore and revert" in linkgit:git[1] for the differences
>  between the three commands.
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index 8bc94d392b..7a01d00f53 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -1604,6 +1604,9 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
>  	}
>  	if (opts->checkout_index < 0 || opts->checkout_worktree < 0)
>  		BUG("these flags should be non-negative by now");
> +	if (opts->checkout_index > 0 && opts->checkout_worktree > 0 &&
> +	    !opts->from_treeish)
> +		die(_("--source required when using --worktree and --staged"));
>  	/*
>  	 * convenient shortcut: "git restore --staged" equals
>  	 * "git restore --staged --source HEAD"
> diff --git a/t/t2070-restore.sh b/t/t2070-restore.sh
> index 076d0df7fc..19efa21fdb 100755
> --- a/t/t2070-restore.sh
> +++ b/t/t2070-restore.sh
> @@ -69,6 +69,11 @@ test_expect_success 'restore --staged uses HEAD as source' '
>  	test_cmp expected actual
>  '
>
> +test_expect_success 'restore --worktree --staged requires --source' '
> +	test_must_fail git restore --worktree --staged first.t 2>err &&
> +	test_i18ngrep "source required when using --worktree and --staged" err
> +'
> +
>  test_expect_success 'restore --ignore-unmerged ignores unmerged entries' '
>  	git init unmerged &&
>  	(
> --
> 2.26.2.526.g744177e7f7