This function uses signed integers for the unix_date and local variables -
if a negative number is supplied and the leap-year condition is not met,
month will be 0, leading to a later read of day_n[-1]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>