Text overlapping: Hovering a text with UUID and /summon.

When you hover a text, containing UUID information and command /summon, it overlaps.

Steps to reproduce:
1. Create a new world with cheats enabled and with /gamerule doMobSpawning true;
2. Do command /say @e. It should display all mobs and players in current loaded chunks;
3. Write /summon and hover on text.

Expected result:
Only text from /summon should appear.

Obtained result:
It shows overlapped text.