[REVIEW 3-5][PATCH] Fix leap year calculation

[Stephan Bergmann]

On 02/29/2012 04:10 AM, Kohei Yoshida wrote:
> The attached patch fixes a bug in our current leap year calculation
> code.  It is based on the algorithm posted on wikipedia[1], and seems to
> correctly identify year 2000 as a leap year.
>
> Without this, Calc would convert 2000-2-29 into 1899-12-30 on load,
> which is ugly but very hard to detect.
>
> Please consider this for 3.5.1, in which case I'll need 3 sign-offs.  I
> haven't pushed this to master yet.  I wanted to run it by Eike first
> before pushing to master.

You can count me in as +1 towards pushing it to all the relevant branches.

Stephan