[PATCH v3 1/2] column: disallow negative padding

[Kristoffer Haugsbakk <code@khaugsbakk.name>]

A negative padding does not make sense and can cause errors in the
memory allocator since it’s interpreted as an unsigned integer.

Reported-by: Tiago Pascoal <tiago@pascoal.net>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
---
 builtin/column.c  |  2 ++
 t/t9002-column.sh | 11 +++++++++++
 2 files changed, 13 insertions(+)

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");
 	if (argc)
 		usage_with_options(builtin_column_usage, options);
 	if (real_command || command) {
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
-- 
2.43.0