Re: [PATCH v2] column: disallow negative padding
On 11-feb-2024 20:27:49, Kristoffer Haugsbakk wrote:
Show 37 quoted lines
> A negative padding does not make sense and can cause errors in the
> memory allocator since it’s interpreted as an unsigned integer.
>
> Disallow negative padding. Also guard against negative padding in
> `column.c` where it is conditionally used.
>
> Reported-by: Tiago Pascoal <tiago@pascoal.net>
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
> ---
>
> Notes (series):
> v2:
> • Incorporate Junio’s changes (guard against negative padding in
> `column.c`)
> • Tweak commit message based on Junio’s analysis
> • Use gettext for error message
> • However I noticed that the “translation string” from `fast-import`
> isn’t a translation string. So let’s invent a new one and use a
> parameter so that it can be used elsewhere.
> • Make a test
>
> builtin/column.c | 2 ++
> column.c | 4 ++--
> t/t9002-column.sh | 11 +++++++++++
> 3 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/column.c b/builtin/column.c
> index e80218f81f9..10ff7e01668 100644
> --- a/builtin/column.c
> +++ b/builtin/column.c
> @@ -45,6 +45,8 @@ int cmd_column(int argc, const char **argv, const char *prefix)
> memset(&copts, 0, sizeof(copts));
> copts.padding = 1;
> argc = parse_options(argc, argv, prefix, options, builtin_column_usage, 0);
> + if (copts.padding < 0)
> + die(_("%s must be non-negative"), "--padding");We clearly inform the user and die. No more OOM errors, or worse. Good.
And the message avoids translation problems. Excellent.
Show 13 quoted lines
> if (argc)
> usage_with_options(builtin_column_usage, options);
> if (real_command || command) {
> diff --git a/column.c b/column.c
> index ff2f0abf399..c723428bc70 100644
> --- a/column.c
> +++ b/column.c
> @@ -189,7 +189,7 @@ void print_columns(const struct string_list *list, unsigned int colopts,
> memset(&nopts, 0, sizeof(nopts));
> nopts.indent = opts && opts->indent ? opts->indent : "";
> nopts.nl = opts && opts->nl ? opts->nl : "\n";
> - nopts.padding = opts ? opts->padding : 1;
> + nopts.padding = (opts && 0 <= opts->padding) ? opts->padding : 1;This changes what Junio proposed. Is this on purpose?
While we're here, I wonder if silently ignoring a negative value in .padding is the right thing to do.
There are several callers of print_columns():
builtin/branch.c: print_columns(&output, colopts, NULL); builtin/clean.c: print_columns(&list, colopts, &copts); builtin/clean.c: print_columns(menu_list, local_colopts, &copts); builtin/column.c: print_columns(&list, colopts, &copts); help.c: print_columns(&list, colopts, &copts); wt-status.c: print_columns(&output, s->colopts, &copts);
I haven't checked it thoroughly but it seems we don't need to add the check we're adding to builtin/column.c, to any of the other callers. However, it is possible that these or other new callers may need it in the future. If so, we should consider doing something like:
diff --git a/column.c b/column.c
index c723428bc7..4f870c725f 100644
--- a/column.c
+++ b/column.c
@@ -186,6 +186,9 @@ void print_columns(const struct string_list *list, unsigned int colopts,
return;
assert((colopts & COL_ENABLE_MASK) != COL_AUTO);
+ if (opts && (0 <= opts->padding))
+ BUG("padding must be non-negative");
+
memset(&nopts, 0, sizeof(nopts));
nopts.indent = opts && opts->indent ? opts->indent : "";
nopts.nl = opts && opts->nl ? opts->nl : "\n";
> nopts.width = opts && opts->width ? opts->width : term_columns() - 1;
> if (!column_active(colopts)) {
> display_plain(list, "", "\n");
> @@ -373,7 +373,7 @@ int run_column_filter(int colopts, const struct column_options *opts)
> strvec_pushf(argv, "--width=%d", opts->width);
> if (opts && opts->indent)
> strvec_pushf(argv, "--indent=%s", opts->indent);
> - if (opts && opts->padding)
> + if (opts && 0 <= opts->padding)
This also differs from Junio's changes.
> strvec_pushf(argv, "--padding=%d", opts->padding);
>
> fflush(stdout);
> diff --git a/t/t9002-column.sh b/t/t9002-column.sh
> index 348cc406582..d5b98e615bc 100755
> --- a/t/t9002-column.sh
> +++ b/t/t9002-column.sh
> @@ -196,4 +196,15 @@ EOF
> test_cmp expected actual
> '
>
> +test_expect_success 'padding must be non-negative' '
> + cat >input <<\EOF &&
> +1 2 3 4 5 6
> +EOF
> + cat >expected <<\EOF &&
> +fatal: --padding must be non-negative
> +EOF
> + test_must_fail git column --mode=column --padding=-1 <input >actual 2>&1 &&
> + test_cmp expected actual
> +'
> +
> test_done
OK
> --
> 2.43.0
>
