TrinityCore/TrinityCore — comment on commit 5ea49613d24ad10b305891a39340155058e5a67e
File:  line 0
By Ka0z:

From your link, in you check @ 3:26, the char start cast frostbolt at his target, in the middle of the cast, the target move of o LoS, the spell casting is cancelled (notice that the char moves after the spell cast is cancelled, not before).