The bug
Enable spawn protection. Attempt to place a block. The block will not place, however it will be removed from your inventory. Relog, or click the empty slot and it will reappear.
With recent (1.15 snapshots) changes moving item usage to the client-side as well to get correct arm movement, this affects even more items, e.g. fire charges used to ignite camp fires.
Code analysis
Code analysis by @unknown can be found in this comment.
Related issues
is duplicated by
MC-107439
Blocks attempted to be placed in a spawn-protection zone are not visibly readded to player's inventory. You can get them back by clicking on the slot.
MC-215738
Spawn protection malfunction
MC-216538
Placing blocks on OP only area causes inventory desync.
MC-225588
Attempting to use fire charges in spawn protection causes a desync
MC-226159
Attempting to place glowstone into a respawn anchor in spawn protection causes a desync
MC-226161
Attempting to take flowers from flower pots in spawn protection causes a desync
relates to
MC-95720
Client-server desync on seemingly invalid block placement
MC-225587
Attempting to apply wax to copper in spawn protection causes a desync
MC-226157
Attempting to lock compasses to lodestones in spawn protection causes a desync
MC-226158
Attempting to use glass bottles in spawn protection causes a desync
MC-11563
Wooden Doors in spawn-protection can be opened but not passed through
Comments
marcono1234
migrated
How do you enable spawn protection? Also, is this in survival mode?
migrated
it's only in a server's propperties, and effects non-ops, no matter what gamemode
marcono1234
And there has to be at least one op, see @unknown's tweet
wobst.michael
Is this still an issue in the most recent versions (currently that is 1.12.2, or the latest 1.13 pre-release) of Minecraft?
Uriel Salischiker
Is this still a issue in the latest version of the game(currently 1.13.1)?
If so, please add it to the affected versions, thanks!
migrated
Affects 20w51a
Placing a candle on a cake in spawn protection will also desync (separate from MC-205212).
migrated
Confirmed for 1.17.1.
Avoma
Can confirm in 1.18.1.
Avoma
Can confirm in 1.18.2 and 22w15a.
Avoma
Can confirm in 1.19.
Avoma
Can confirm in 1.19.2.
Machine Maker
Still happens in 1.21.1
md_5
The following is based on decompiled version of Minecraft 1.9 using MCP 9.24 beta. All method and class names are the names used in the decompiled version.
The method
net.minecraft.network.NetHandlerPlayServer.func_184337_a(CPacketPlayerTryUseItem)should probably synchronize the player inventory based on the returnedEnumActionResultby the call to the methodnet.minecraft.server.management.PlayerInteractionManager.func_187251_a(EntityPlayer, World, ItemStack, EnumHand, BlockPos, EnumFacing, float, float, float), or if it fails because for example the spawn protection prevents placing blocks.This desync is normally only visible if the spawn protection prevents placing a block because this is only tested server-side. Placing a block behind the worldborder or above the build limit is tested client-side as well. The latter situations can create desync if the client receives changes to the worldborder too late or if the built height is lower than the default one (this creates block desync for breaking blocks as well).
But I guess @unknown knows more about this