Restore previous PlayerToggleSneakEvent behaviour (#12815)

Co-authored-by: Bjarne Koll <git@lynxplay.dev>

Author: ookiegajwa

paper-server/patches/features/0030-Optimise-collision-checking-in-player-move-packet-ha.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Optimise collision checking in player move packet handling
 Move collision logic to just the hasNewCollision call instead of getCubes + hasNewCollision
 
 diff --git a/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/net/minecraft/server/network/ServerGamePacketListenerImpl.java
-index 08aba415735733f5968fd032ab7ca249cdcf6cde..ee4397711625344622c81424afd11fd6d967efba 100644
+index 39a706ae5be3681c32c297c73d57b9bcf56638d4..c8dfd7fdaabc047eec05f1b78c97b551aa0fc586 100644
 --- a/net/minecraft/server/network/ServerGamePacketListenerImpl.java
 +++ b/net/minecraft/server/network/ServerGamePacketListenerImpl.java
 @@ -606,6 +606,7 @@ public class ServerGamePacketListenerImpl

paper-server/patches/sources/net/minecraft/server/network/ServerGamePacketListenerImpl.java.patch

@@ -166,15 +166,15 @@
 +        // CraftBukkit end
 +        // Paper start - PlayerToggleSneakEvent
 +        net.minecraft.world.entity.player.Input lastInput = this.player.getLastClientInput();
-+        boolean shiftKeyDown = packet.input().shift();
 +        if (lastInput.shift() != packet.input().shift()) {
 +            // Has sneak changed
 +            org.bukkit.event.player.PlayerToggleSneakEvent event = new org.bukkit.event.player.PlayerToggleSneakEvent(this.getCraftPlayer(), packet.input().shift());
 +            this.cserver.getPluginManager().callEvent(event);
 +
 +            // Technically the player input and the flag is desynced, but this is previous behavior.. so should be fine?
-+            if (event.isCancelled()) {
-+               shiftKeyDown = this.player.isShiftKeyDown();
++            if (!event.isCancelled() && this.player.hasClientLoaded()) {
++                // Only set the shift key status if the shift input has changed and the event has not been cancelled
++                this.player.setShiftKeyDown(packet.input().shift());
 +            }
 +        }
 +        // Paper end - PlayerToggleSneakEvent
@@ -183,7 +183,7 @@
              this.player.resetLastActionTime();
 -            this.player.setShiftKeyDown(packet.input().shift());
 -        }
-+            this.player.setShiftKeyDown(shiftKeyDown); // Paper
++            // this.player.setShiftKeyDown(packet.input().shift()); // Paper - move up and only set if event is not cancelled.
 +        }
 +        // Paper start - Add option to make parrots stay
 +        if (packet.input().shift() && this.player.level().paperConfig().entities.behavior.parrotsAreUnaffectedByPlayerMovement) {