When losing the Shockwave spell while a shockwave projectile is currently flying, it stop damaging enemies in its path on impact. The projectile simply stops working.

Repro:
1. Acquire Shockwave with Doom
2. Wait for the creep to be digested
3. Find another neutral creep with different spells
4. Cast Shockwave towards enemies
5. While the projectile still flies, devour the neutral creep to gain new spells

Result: Once the Shockwave spell is lost, the already launched projectile stops damaging enemies it hits.

Expected: Already cast instances of spells should continue to work, regardless of whether the spell is still available or not.

Note: This works fine for Rubick. When he steals a new spell after releasing the shockwave, his shockwave still works normally, damaging all enemies it hits.