paper-server/patches/sources/net/minecraft/world/level/block/piston/PistonBaseBlock.java.patch

@@ -61,6 +61,15 @@
              }
  
              level.playSound(null, pos, SoundEvents.PISTON_CONTRACT, SoundSource.BLOCKS, 0.5F, level.random.nextFloat() * 0.15F + 0.6F);
+@@ -249,7 +_,7 @@
+     }
+ 
+     public static boolean isPushable(BlockState state, Level level, BlockPos pos, Direction movementDirection, boolean allowDestroy, Direction pistonFacing) {
+-        if (pos.getY() < level.getMinY() || pos.getY() > level.getMaxY() || !level.getWorldBorder().isWithinBounds(pos)) {
++        if (pos.getY() < level.getMinY() || pos.getY() > level.getMaxY() || !level.getWorldBorder().isWithinBounds(pos) || !level.getWorldBorder().isWithinBounds(pos.relative(movementDirection))) { // Paper - Fix piston world border check
+             return false;
+         } else if (state.isAir()) {
+             return true;
 @@ -305,12 +_,54 @@
              BlockState[] blockStates = new BlockState[toPush.size() + toDestroy.size()];
              Direction direction = extending ? facing : facing.getOpposite();