Re: [PATCH 3/9] string: Add Kunit tests for strcat() family

[Alexander Potapenko]

> +static void strncat_test(struct kunit *test)
> +{
> +       char dest[8];
> +
> +       /* Destination is terminated. */
> +       memset(dest, 0, sizeof(dest));
> +       KUNIT_EXPECT_EQ(test, strlen(dest), 0);
> +       /* Empty copy of size 0 does nothing. */
> +       KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0) == dest);
> +       KUNIT_EXPECT_STREQ(test, dest, "");
> +       /* Empty copy of size 1 does nothing too. */
> +       KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1) == dest);
> +       KUNIT_EXPECT_STREQ(test, dest, "");
> +       /* Copy of max 0 characters should do nothing. */
> +       KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0) == dest);
> +       KUNIT_EXPECT_STREQ(test, dest, "");
> +
> +       /* 4 characters copied in, even if max is 8. */
> +       KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8) == dest);
> +       KUNIT_EXPECT_STREQ(test, dest, "four");
> +       KUNIT_EXPECT_EQ(test, dest[5], '\0');

Maybe also add a test case for strncat(dest, "four", 4) that checks
that the fourth byte of dest is not 0?