Check for long lines before partial truncation.
Check for long lines before partial truncation.

Otherwise someone can make the bot (try to) print a very long line by
ensuring the output is more than 3 lines long, and the long line is
before the cut off, e.g.

     println!("{}\n\n\n", "x".repeat(1_000_000));

cogumbreiro/scribble-playpen,epdtry/cse333-rust-slides,cogumbreiro/scribble-playpen,Enamex/rust-playpen,cogumbreiro/scribble-playpen,drlagos/unify-playpen,tilpner/rust-playpen,tilpner/rust-playpen,Enamex/rust-playpen,rust-lang/rust-playpen,cogumbreiro/sepi-playpen,rust-lang/rust-playpen,tilpner/rust-playpen,epdtry/cse333-rust-slides,Limvot/kraken-playpen,drlagos/unify-playpen,chris-morgan/rust-playpen,lastorset/rust-playpen,tilpner/rust-playpen,rust-lang/rust-playpen,Limvot/kraken-playpen,plietar/pony-playpen,Limvot/kraken-playpen,plietar/pony-playpen,rust-lang/rust-playpen,drlagos/mpisessions-playpen,cogumbreiro/sepi-playpen,chris-morgan/rust-playpen,Enamex/rust-playpen,epdtry/cse333-rust-slides,Enamex/rust-playpen,lastorset/rust-playpen,epdtry/cse333-rust-slides,drlagos/mpisessions-playpen,chris-morgan/rust-playpen,chris-morgan/rust-playpen,lastorset/rust-playpen,lastorset/rust-playpen,plietar/pony-playpen,plietar/pony-playpen