snprintf with overlapping source and dest strings

[michaelortmann]

eggdrop/src/mod/server.mod/server.c

Line 586 in 6e9aeac

egg_snprintf(newnicks, sizeof newnicks, "%s,%s", newnicks, newnick);

snprintf with overlapping source and dest strings is undefined behaviour, dst is char * restrict.

After inserting debug code i was able to see a real bug here.

I found this with #1028, but Will Buckner also found this before me in 2005:

http://lists.eggheads.org/pipermail/eggdev/2005-April/015490.html

He mentioned a patch, but i checked eggdrops commit history and this patch never made it into eggdrop.

My attempt to contact Mr. Buckner failed due to his old email address being not valid anymore.