Aucbvax.425 NET.v7bugs utzoo!duke!vax135!ucbvax!mark Mon Oct 13 18:59:49 1980 cu Cu seems to keep track of what the user types in a line buffer. There is no check for overflowing this buffer. Since one can easily go for a long time in a screen editor without getting a return, it is easy to core dump the receive process. The following patch seems to fix it: at the beginning of the routine rd, before *p++=c; add if (p >= &b[sizeof b]) p = b; This fix was arrived at quickly, and it is possible that the author will prefer a different fix, such as if (p >= &b[sizeof b]) p--; after *p++=c;. Actually, it seems like cu has little business keeping a line buffer unless the first character was a tilde.