Setting "Spectator Generate Chunks" Gamerule to 'False' and going to the edge of current generated chunks causing glitches / flashes / parts of chunks disappearing / other graphic glitches.
How to reproduce:
Set Gamerule 'Spectator Generate Chunks' to 'False'
Go to the edge of current generated chunks / terrain and look around
There will be some graphical glitches / bugs / flashing textures of the terrain when moving camera around (Mouse) and the Player (W, A, S, D, Space, Shift) ...
This might happen also in Server (Generate new world in Server or copy / paste Singleplayer generated world into Server's directory, then start the Server and set the gamerule);
Screenshots & Video Uploaded;
New Example World Seed: -6680014990359507554
Example Video: http://www.mediafire.com/file/dftes4tk11whu2b/Spectator_Chunks_Bugs.mp4
It's not duplicate, because MC 88359 is for the bug 'Chunks dissapear' when you are outside with this gamerule. This can be another bug, but here (IN this issue) - The problem is when you are inside the chunks (Not walking outside of them) and rotate the camera (Mouse) and moving around. The textures are flashing sometime and there are glitches.