MantisBT - Zandronum
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IDProjectCategoryView StatusDate SubmittedLast Update
0001634Zandronum[All Projects] Bugpublic2013-12-31 22:312018-09-30 21:58
ReporterAlexMax 
Assigned ToEdward-san 
PrioritynormalSeverityminorReproducibilityalways
StatusclosedResolutionfixed 
PlatformOSOS Version
Product Version1.4 
Target Version3.0Fixed in Version3.0 
Summary0001634: Weird spawn telefragging behavior on Duel32 + Transfer Heights
DescriptionEver since releasing duel32e I have noticed that it is MUCH easier to telefrag someone by spawning in. It might have something to do with Transfer Heights, but I'm pretty sure DooM spawnfrags somebody as a last resort or at the end of an extremely unlucky set of RNG rolls.
Steps To Reproduce1. Join a duel32e server and spawn into it. Don't move.
2. Have a second player join the server and spawn.
3. If you don't telefrag the other player, quit the server, rejoin, and respawn until you do.
Additional InformationHere's the WAD to reproduce.

'http://files.funcrusher.net/wads/duel32e.pk3 [^]'

Seeing as it's _very_ repeatable, it should be fairly easy to attach a debugger to the server and step through the respawning logic to see what goes wrong.
TagsNo tags attached.
Relationships
related to 0002791confirmed  Moving slightly off a spawn makes you vunerable to join/defect telefrag in team games 
has duplicate 0002577closed AlexMax Telefragging on join, even with other open available spawns 
related to 0001253closed  Team telefrag issue: G_CheckSpot always returns true if the spawn spot is > player height for the sector it's in 
related to 0001032closed Torr Samaho Z-Height support for player starts 
related to 0001499closed  Slight chance that players will spawn on each other (same spawnpoint) 
Attached Files
Issue History
Date ModifiedUsernameFieldChange
2013-12-31 22:31AlexMaxNew Issue
2014-01-03 11:08Torr SamahoNote Added: 0007862
2014-06-11 15:47WatermelonRelationship addedrelated to 0001253
2014-06-11 15:48WatermelonRelationship addedrelated to 0001032
2014-06-11 15:49WatermelonRelationship addedrelated to 0001499
2014-06-11 15:50WatermelonStatusnew => acknowledged
2014-06-11 15:50WatermelonStatusacknowledged => confirmed
2016-01-29 21:17DuskRelationship addedhas duplicate 0002577
2016-07-15 14:51Ru5tK1ngNote Added: 0015317
2016-07-15 19:17Edward-sanNote Added: 0015318
2016-07-15 19:17Edward-sanStatusconfirmed => feedback
2016-07-15 20:54Edward-sanNote Edited: 0015318bug_revision_view_page.php?bugnote_id=15318#r9282
2016-07-15 21:00Edward-sanNote Added: 0015320
2016-07-15 21:00Edward-sanStatusfeedback => confirmed
2016-07-16 13:07Edward-sanAssigned To => Edward-san
2016-07-16 13:07Edward-sanStatusconfirmed => assigned
2016-07-16 13:11Edward-sanNote Added: 0015327
2016-07-16 13:11Edward-sanStatusassigned => needs review
2016-07-17 11:41Edward-sanNote Edited: 0015327bug_revision_view_page.php?bugnote_id=15327#r9345
2016-07-17 19:35WaTaKiDNote Added: 0015362
2016-07-18 15:35Ru5tK1ngNote Added: 0015375
2016-07-18 22:31AlexMaxNote Added: 0015379
2016-07-18 22:31AlexMaxNote Edited: 0015379bug_revision_view_page.php?bugnote_id=15379#r9357
2016-07-19 00:51Edward-sanNote Added: 0015381
2016-10-09 21:37Edward-sanNote Added: 0015865
2016-10-09 21:37Edward-sanStatusneeds review => needs testing
2016-10-09 21:37Edward-sanProduct Version => 1.4
2016-10-09 21:37Edward-sanTarget Version => 3.0
2016-10-15 16:31Ru5tK1ngNote Added: 0016017
2016-10-15 16:32Ru5tK1ngRelationship addedrelated to 0002791
2016-10-15 16:32Ru5tK1ngStatusneeds testing => resolved
2016-10-15 16:32Ru5tK1ngResolutionopen => fixed
2016-10-15 16:32Ru5tK1ngFixed in Version => 3.0
2018-09-30 21:58Blzut3Statusresolved => closed

Notes
(0007862)
Torr Samaho   
2014-01-03 11:08   
Is the behavior in Skulltag, Zandronum and ZDoom the same?
(0015317)
Ru5tK1ng   
2016-07-15 14:51   
This issue still persists in 2.1.2 and 3.0. I can't reproduce it in ZDoom because spectators don't exist there. Repeatedly spamming changemap or restarting the server never replicated the telefrag issue.
(0015318)
Edward-san   
2016-07-15 19:17   
(edited on: 2016-07-15 20:54)
Which map has the problem? Which flags/settings should be used?

[edit] AlexMax provided me some info on irc:

Quote

<AlexMax> edward-san: Do it on the start map
<AlexMax> there are eight spawns, but only four actual spawn locations
<edward-san> deathmatch mode?
<AlexMax> Try it in duel mode


And managed to reproduce it.
(0015320)
Edward-san   
2016-07-15 21:00   
So, the problem is caused by the second player's body being still a spectator when the deathmatch spot checker code is called.

In fact, when G_CheckSpot is called in function SelectRandomDeathmatchSpot, the second player's mobj flags2 have MF2_THRUACTORS, which makes the function PIT_CheckThing return true, leading the whole P_CheckPosition code ignore the presence of the already present player.

The telefrag happens because after the spot is found the player is spawned and the spectator data is cleared, so P_CheckPosition finds the old player, then the old player is killed.
(0015327)
Edward-san   
2016-07-16 13:11   
(edited on: 2016-07-17 11:41)
Should be fixed with'https://bitbucket.org/zandronum/zandronum-sandbox-stable/commits/da62ad7f93c095f02b93e3f6c5c8b20d05b68536 [^]' (2.x branch).


[edit] For testing purposes I added a merge of the fix (partial, no docs) to 3.0 branch:'https://bitbucket.org/zandronum/zandronum-sandbox/commits/b9b0ff69286e6d9d130509d343fb8c4fc8cbf5bf [^]' .
(0015362)
WaTaKiD   
2016-07-17 19:35   
this 3.0 build contains the above commit: 'https://www.dropbox.com/s/r3tydzxkore1vkc/zandronum-3.0-r160717-1138-b9b0ff6-windows.zip?dl=0 [^]'
(0015375)
Ru5tK1ng   
2016-07-18 15:35   
That build seemed to fix the issue. I couldn't reproduce the bug after trying repeatedly for several minutes.
(0015379)
AlexMax   
2016-07-18 22:31   
Fantastic! Thanks for the attention.
(0015381)
Edward-san   
2016-07-19 00:51   
I'd like to know if the related tickets are solved with that build as well.
(0015865)
Edward-san   
2016-10-09 21:37   
The fix for this specific issue was merged in 3.0 upstream:'https://bitbucket.org/Torr_Samaho/zandronum/commits/3114b070fe24 [^]' . The build in 0002866 should contain it.
(0016017)
Ru5tK1ng   
2016-10-15 16:31   
I pulled the latest changes from Zan 3.0 and my test results were still the same. I couldn't tele frag the opponent by repeatedly joining even after coming off of an intermission screen.