The check in parse_user that eventually makes it into committer_date and tagger_date is: else if (mode == 3 && isdigit(*p)) { *date = atol(p); mode++; } Since isdigit('-') is always false, date will never be negative. Thus the sign of this function: static int cmp_age(int age1, int age2) { if (age1 != 0 && age2 != 0) return age2 - age1; if (age1 == 0 && age2 == 0) return 0; if (age1 == 0) return +1; return -1; } Will always be the same as the sign of this function: static inline int cmp_age(int age1, int age2) { return age2 - age1; } Signed-off-by: Jason A. Donenfeld <[email protected]> Idea-by: Lukas Fleischer <[email protected]>