Phillip Wood <phillip.wood123@xxxxxxxxx> writes:
> From: Phillip Wood <phillip.wood@xxxxxxxxxxxxx>
>
> When the user runs
>
> git diff --no-index file directory
>
> we follow the behavior of POSIX diff and rewrite the arguments as
>
> git diff --no-index file directory/file
>
> Doing that when "file" is "-" (which means "read from stdin") does not
> make sense so we should error out if the user asks us to compare "-" to
> a directory. This matches the behavior of GNU diff and diff on *BSD.
"git diff --no-index directory file" would also be the same way.
Makes sense.
> - if (path[0] == file_from_standard_input ||
> - path[1] == file_from_standard_input)
> - return;
> - isdir0 = is_directory(path[0]);
> - isdir1 = is_directory(path[1]);
We used to silently did nonsense, I guess.
> + isdir0 = path[0] != file_from_standard_input && is_directory(path[0]);
> + isdir1 = path[1] != file_from_standard_input && is_directory(path[1]);
> +
> + if ((path[0] == file_from_standard_input && isdir1) ||
> + (isdir0 && path[1] == file_from_standard_input))
> + die(_("cannot compare stdin to a directory"));
OK. It is much better than turning "diff - D" into "diff - D/-".
If D were a missing or a misspelt directory name, the rest of the
function will just leave the original intact and let comparison
between the standard input and D that does not exist, and will fail
correctly anyway. Good.
> if (isdir0 == isdir1)
> return;
> if (isdir0) {
> diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh
> index 4e9fa0403d..5bfb282e98 100755
> --- a/t/t4053-diff-no-index.sh
> +++ b/t/t4053-diff-no-index.sh
> @@ -205,4 +205,9 @@ test_expect_success POSIXPERM,SYMLINKS 'diff --no-index normalizes: mode not lik
> test_cmp expected actual
> '
>
> +test_expect_success 'diff --no-index refuses to diff stdin and a directory' '
> + test_must_fail git diff --no-index -- - a </dev/null 2>err &&
> + grep "fatal: cannot compare stdin to a directory" err
> +'
> +
> test_done
