fail(), fail_if(), or fail_unless() warns about "too many arguments for format" because of an extra NULL argument

[ppisar]

Compiling fail(), fail_if(), or fail_unless() macros emits a warning like this:

/builddir/build/BUILD/libdnf-0.73.4-build/libdnf-0.73.4/tests/hawkey/test_goal.cpp:439:18: warning: too many arguments for format [-Wformat-extra-args]
  439 |             fail("assert_list_names(): list too short");
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The cause is that the macros pass an extra NULL argument:

#define fail(...) _ck_assert_failed(__FILE__, __LINE__, "Failed" , ## __VA_ARGS__, NULL)

to _ck_assert_failed() function declared with check for a printf formatting string:

CK_DLL_EXP void CK_EXPORT _ck_assert_failed(const char *file, int line,
                                            const char *expr, const char *msg,
                                            ...) CK_ATTRIBUTE_NORETURN CK_ATTRIBUTE_FORMAT(printf, 4, 5);

Then the exampled macro expands to:

_ck_assert_failed("FILE", LINE, "Failed", "assert_list_names(): list too short", NULL);

where the NULL argument is superfluous.

Observed with check-0.15.2 and gcc-15.0.1.

I guess the NULL argument should be removed as in ck_assert_msg() definition. Though, maybe you keep the deprecated macros broken on purposes, to preserve compatibility.