Use our own firstNonNull to maintain back-compat.

Fixes WORLDEDIT-3567.

build.gradle

@@ -21,7 +21,7 @@ buildscript {
 
     configurations.all {
         resolutionStrategy {
-            force 'com.google.guava:guava:17.0'
+            force 'com.google.guava:guava:21.0'
         }
     }
 

worldedit-core/build.gradle

@@ -5,7 +5,7 @@ dependencies {
     compile 'de.schlichtherle:truezip:6.8.3'
     compile 'rhino:js:1.7R2'
     compile 'org.yaml:snakeyaml:1.9'
-    compile 'com.google.guava:guava:17.0'
+    compile 'com.google.guava:guava:21.0'
     compile 'com.sk89q:jchronic:0.2.4a'
     compile 'com.google.code.findbugs:jsr305:1.3.9'
     compile 'com.thoughtworks.paranamer:paranamer:2.6'

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/ReplaceParser.java

@@ -30,7 +30,8 @@ import com.sk89q.worldedit.function.pattern.Pattern;
 import com.sk89q.worldedit.util.command.argument.CommandArgs;
 import com.sk89q.worldedit.util.command.composition.SimpleCommand;
 
-import static com.google.common.base.Objects.firstNonNull;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
+
 
 public class ReplaceParser extends SimpleCommand<Contextual<? extends RegionFunction>> {
 

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Apply.java

@@ -27,8 +27,8 @@ import com.sk89q.worldedit.function.visitor.RegionVisitor;
 import com.sk89q.worldedit.regions.NullRegion;
 import com.sk89q.worldedit.regions.Region;
 
-import static com.google.common.base.Objects.firstNonNull;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
 
 public class Apply implements Contextual<Operation> {
 

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Deform.java

@@ -19,7 +19,6 @@
 
 package com.sk89q.worldedit.function.factory;
 
-import com.google.common.base.Objects;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.Vector;
 import com.sk89q.worldedit.WorldEditException;
@@ -36,6 +35,7 @@ import com.sk89q.worldedit.regions.Region;
 import java.util.List;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
 
 public class Deform implements Contextual<Operation> {
 
@@ -123,7 +123,7 @@ public class Deform implements Contextual<Operation> {
         final Vector zero;
         Vector unit;
 
-        Region region = Objects.firstNonNull(context.getRegion(), this.region);
+        Region region = firstNonNull(context.getRegion(), this.region);
 
         switch (mode) {
             case UNIT_CUBE:

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Paint.java

@@ -33,9 +33,9 @@ import com.sk89q.worldedit.math.noise.RandomNoise;
 import com.sk89q.worldedit.regions.NullRegion;
 import com.sk89q.worldedit.regions.Region;
 
-import static com.google.common.base.Objects.firstNonNull;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.sk89q.worldedit.regions.Regions.*;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
 
 public class Paint implements Contextual<Operation> {
 

worldedit-core/src/main/java/com/sk89q/worldedit/util/GuavaUtil.java

@@ -0,0 +1,33 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util;
+
+import javax.annotation.Nullable;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public final class GuavaUtil {
+
+    private GuavaUtil() {}
+
+    public static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
+        return first != null ? first : checkNotNull(second);
+    }
+}