PaperMC/paper-server/patches/sources/net/minecraft/world/item/ThrowablePotionItem.java.patch

--- a/net/minecraft/world/item/ThrowablePotionItem.java
+++ b/net/minecraft/world/item/ThrowablePotionItem.java
@@ -22,11 +22,28 @@
     public InteractionResult use(Level world, Player user, InteractionHand hand) {
         ItemStack itemStack = user.getItemInHand(hand);
         if (world instanceof ServerLevel serverLevel) {
-            Projectile.spawnProjectileFromRotation(ThrownPotion::new, serverLevel, itemStack, user, -20.0F, PROJECTILE_SHOOT_POWER, 1.0F);
+            // Paper start - PlayerLaunchProjectileEvent
+            final Projectile.Delayed<ThrownPotion> thrownPotion = Projectile.spawnProjectileFromRotationDelayed(ThrownPotion::new, serverLevel, itemStack, user, -20.0F, PROJECTILE_SHOOT_POWER, 1.0F);
+            // Paper start - PlayerLaunchProjectileEvent
+            com.destroystokyo.paper.event.player.PlayerLaunchProjectileEvent event = new com.destroystokyo.paper.event.player.PlayerLaunchProjectileEvent((org.bukkit.entity.Player) user.getBukkitEntity(), org.bukkit.craftbukkit.inventory.CraftItemStack.asCraftMirror(itemStack), (org.bukkit.entity.Projectile) thrownPotion.projectile().getBukkitEntity());
+            if (event.callEvent() && thrownPotion.attemptSpawn()) {
+                if (event.shouldConsume()) {
+                    itemStack.consume(1, user);
+                } else if (user instanceof net.minecraft.server.level.ServerPlayer) {
+                    ((net.minecraft.server.level.ServerPlayer) user).getBukkitEntity().updateInventory();
+                }
+
+                user.awardStat(Stats.ITEM_USED.get(this));
+            } else {
+                if (user instanceof net.minecraft.server.level.ServerPlayer) {
+                    ((net.minecraft.server.level.ServerPlayer) user).getBukkitEntity().updateInventory();
+                }
+                return InteractionResult.FAIL;
+            }
+            // Paper end - PlayerLaunchProjectileEvent
         }
 
-        user.awardStat(Stats.ITEM_USED.get(this));
-        itemStack.consume(1, user);
+        // Paper - PlayerLaunchProjectileEvent - move up
         return InteractionResult.SUCCESS;
     }