ID:2396549
 
Resolved
Client garbage collection could sometimes claim objects newly re-registered for a vis_contents list before said vis_contents list was actually received to protect them from recycling.
BYOND Version:512.1448
Operating System:Windows 7 Ultimate 64-bit
Web Browser:Firefox 61.0
Applies to:Dream Seeker
Status: Resolved (512.1449)

This issue has been resolved.
Descriptive Problem Summary:

Sometimes teleporting from one location full of vis_contents to another full of vis_contents does not correctly show some of the new vis_contents.

Is not necessarily heap corruption like last time, DreamSeeker doesn't crash on exit or anything.

Code Snippet (if applicable) to Reproduce Problem:
Minimal test project

Expected Results:
Letting the movement happen automatically for some time, the turfs always maintain their vis_contents, with the grid-patterned object always covering the blue turf.

Actual Results:
Occasionally during the teleport from the top-right of the map back to the bottom-left, various turfs lose their vis_contents - usually a rectangle in the corner and one random outlying turf.

Tapping "Stop Gliding" or any movement key as soon as this happens lets the state be examined. "Reconnect" fixes the issue, as does walking out of range of the problematic turfs and then walking back in.

Tapping "Toggle Z Shifting" causes the issue to become very obvious immediately. It's also laggy while it's on but this is kind of to be expected due to all the teleporting. After it's disabled, however, the client begins visibly pausing while moving (hold a movement key and notice the stutters), despite the ambient conditions being the same as before Z Shifting was enabled at all.

Does the problem occur:
Every time? Or how often? Seemingly at random.
In other games? Yes, in a test project.
In other user accounts? Unknown.
On other computers? Unknown.

When does the problem NOT occur?

Not yet observed in a real project. I happened to notice while booting up this old test project for unrelated reasons.

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)

Unknown.

Workarounds:

Unknown.
Lummox JR resolved issue with message:
Client garbage collection could sometimes claim objects newly re-registered for a vis_contents list before said vis_contents list was actually received to protect them from recycling.