Hello no, it's not in SVN. Nobody with access likes that junk.
/Donate lets you give some credits to the team without specifying a destination. You just do /donate number and they're doled out to your team members.. somehow.
This is how I understand donate;
1) You type /donate 1000 (for example) while on humans
2) The server takes 1000 and divides it by the number of players on your team (9, in this example)
3) 1000/9=111.1 repeating
4) Round down if decimals exist
5) 111 credits are donated to each player
Now, I don't know if the 1 leftover credit is stored in the server's memory to be included with the next /donate command, or if it simply discarded. You'd have to ask whoever it was that was responsible for tracking the /share and /donate code additions.