PaperMC/nms-patches/PathfinderGoalTame.patch

--- a/net/minecraft/server/PathfinderGoalTame.java
+++ b/net/minecraft/server/PathfinderGoalTame.java
@@ -45,7 +45,8 @@
                 int i = this.entity.getTemper();
                 int j = this.entity.getMaxDomestication();
 
-                if (j > 0 && this.entity.bc().nextInt(j) < i) {
+                // CraftBukkit - fire EntityTameEvent
+                if (j > 0 && this.entity.bc().nextInt(j) < i && !org.bukkit.craftbukkit.event.CraftEventFactory.callEntityTameEvent(this.entity, (EntityHuman) this.entity.passenger).isCancelled() && this.entity.passenger instanceof EntityHuman) {
                     this.entity.h((EntityHuman) this.entity.passenger);
                     this.entity.world.broadcastEntityEffect(this.entity, (byte) 7);
                     return;
@@ -54,8 +55,16 @@
                 this.entity.u(5);
             }
 
-            this.entity.passenger.mount((Entity) null);
-            this.entity.passenger = null;
+            // CraftBukkit start - Handle dismounting to account for VehicleExitEvent being fired.
+            if (this.entity.passenger != null) {
+                this.entity.passenger.mount((Entity) null);
+                // If the entity still has a passenger, then a plugin cancelled the event.
+                if (this.entity.passenger != null) {
+                    return;
+                }
+            }
+            // this.entity.passenger = null;
+            // CraftBukkit end
             this.entity.cW();
             this.entity.world.broadcastEntityEffect(this.entity, (byte) 6);
         }