fix //calc still being able to crash servers

core/src/main/java/com/boydti/fawe/Fawe.java

@@ -116,6 +116,7 @@ import com.sk89q.worldedit.internal.LocalWorldAdapter;
 import com.sk89q.worldedit.internal.command.WorldEditBinding;
 import com.sk89q.worldedit.internal.expression.Expression;
 import com.sk89q.worldedit.internal.expression.runtime.ExpressionEnvironment;
+import com.sk89q.worldedit.internal.expression.runtime.For;
 import com.sk89q.worldedit.internal.expression.runtime.Functions;
 import com.sk89q.worldedit.math.convolution.HeightMap;
 import com.sk89q.worldedit.math.interpolation.KochanekBartelsInterpolation;
@@ -645,6 +646,7 @@ public class Fawe {
             WorldEditExpressionEnvironment.inject(); // Optimizations + features
             Expression.inject(); // Optimizations
             Functions.inject(); // Optimizations
+            For.inject(); // Fixes
             // BlockData
             BlockData.inject(); // Temporary fix for 1.9.4
             BundledBlockData.inject(); // Add custom rotation

core/src/main/java/com/sk89q/worldedit/command/UtilityCommands.java

@@ -87,10 +87,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.UUID;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
 import java.util.stream.Collectors;
 
 
@@ -552,21 +549,30 @@ public class UtilityCommands extends MethodCommands {
         try {
             FaweLimit limit = FawePlayer.wrap(actor).getLimit();
             final Expression expression = Expression.compile(input);
-            double[] result = new double[] { Double.NaN };
+
             ExecutorService executor = Executors.newSingleThreadExecutor();
+            Future<Double> futureResult = executor.submit(new Callable<Double>() {
+                @Override
+                public Double call() throws Exception {
+
+                    return expression.evaluate();
+                }
+            });
+
+            Double result = Double.NaN;
             try {
-                executor.invokeAll(Arrays.asList(new Callable<Object>() {
-                    @Override
-                    public Object call() throws Exception {
-                        result[0] =  expression.evaluate();
-                        return null;
-                    }
-                }), limit.MAX_EXPRESSION_MS, TimeUnit.MILLISECONDS); // Default timeout of 50 milliseconds to prevent abuse.
+                result = futureResult.get(limit.MAX_EXPRESSION_MS, TimeUnit.MILLISECONDS);
             } catch (InterruptedException e) {
-                throw new RuntimeException(e);
+                e.printStackTrace();
+            } catch (ExecutionException e) {
+                e.printStackTrace();
+            } catch (TimeoutException e) {
+                futureResult.cancel(true);
+                e.printStackTrace();
             }
-            executor.shutdown();
-            actor.print(BBC.getPrefix() + "= " + result[0]);
+
+            executor.shutdownNow();
+            actor.print(BBC.getPrefix() + "= " + result);
         } catch (EvaluationException e) {
             actor.printError(String.format(
                     "'%s' could not be parsed as a valid expression", input));

core/src/main/java/com/sk89q/worldedit/internal/expression/runtime/For.java

@@ -0,0 +1,76 @@
+package com.sk89q.worldedit.internal.expression.runtime;
+
+import com.sk89q.worldedit.command.UtilityCommands;
+import com.sk89q.worldedit.internal.expression.Expression;
+import com.sk89q.worldedit.internal.expression.parser.ParserException;
+
+public class For extends Node {
+    RValue init;
+    RValue condition;
+    RValue increment;
+    RValue body;
+
+    public For(int position, RValue init, RValue condition, RValue increment, RValue body) {
+        super(position);
+        this.init = init;
+        this.condition = condition;
+        this.increment = increment;
+        this.body = body;
+    }
+
+    public double getValue() throws EvaluationException {
+
+        int iterations = 0;
+        double ret = 0.0D;
+        this.init.getValue();
+
+        for(; this.condition.getValue() > 0.0D; this.increment.getValue()) {
+
+            if(iterations > 256) {
+                throw new EvaluationException(this.getPosition(), "Loop exceeded 256 iterations.");
+            }
+
+            if(Thread.currentThread().isInterrupted()){
+                throw new EvaluationException(this.getPosition(), "Thread has been interuppted.");
+            }
+
+            ++iterations;
+
+            try {
+                ret = this.body.getValue();
+            } catch (BreakException var5) {
+                if(!var5.doContinue) {
+                    return ret;
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public char id() {
+        return 'F';
+    }
+
+    public String toString() {
+        return "for (" + this.init + "; " + this.condition + "; " + this.increment + ") { " + this.body + " }";
+    }
+
+    public RValue optimize() throws EvaluationException {
+        RValue newCondition = this.condition.optimize();
+        return (RValue)(newCondition instanceof Constant && newCondition.getValue() <= 0.0D?(new Sequence(this.getPosition(), new RValue[]{this.init, new Constant(this.getPosition(), 0.0D)})).optimize():new For(this.getPosition(), this.init.optimize(), newCondition, this.increment.optimize(), this.body.optimize()));
+    }
+
+    public RValue bindVariables(Expression expression, boolean preferLValue) throws ParserException {
+        this.init = this.init.bindVariables(expression, false);
+        this.condition = this.condition.bindVariables(expression, false);
+        this.increment = this.increment.bindVariables(expression, false);
+        this.body = this.body.bindVariables(expression, false);
+        return this;
+    }
+
+    public static Class<For> inject() {
+        return For.class;
+    }
+}
+