Index: /trunk/build.xml
===================================================================
--- /trunk/build.xml	(revision 13303)
+++ /trunk/build.xml	(revision 13304)
@@ -316,4 +316,5 @@
             <compilerarg value="-XDignore.symbol.file"/>
             <compilerarg value="-Xep:ReferenceEquality:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
+            <compilerarg value="-Xep:StringSplitter:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
             <compilerarg line="-Xmaxwarns 1000"/>
         </javac>
@@ -345,4 +346,5 @@
             <compilerarg value="-Xep:FloatingPointLiteralPrecision:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
             <compilerarg value="-Xep:ShortCircuitBoolean:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
+            <compilerarg value="-Xep:StringSplitter:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
             <compilerarg value="-Xep:JdkObsolete:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
             <compilerarg line="-Xmaxwarns 1000"/>
Index: /trunk/src/org/openstreetmap/josm/data/osm/QuadBuckets.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/QuadBuckets.java	(revision 13303)
+++ /trunk/src/org/openstreetmap/josm/data/osm/QuadBuckets.java	(revision 13304)
@@ -389,4 +389,5 @@
 
     @Override
+    @SuppressWarnings("ModifyCollectionInEnhancedForLoop")
     public boolean retainAll(Collection<?> objects) {
         for (T o : this) {
@@ -394,4 +395,6 @@
                 continue;
             }
+            // In theory this could cause a ConcurrentModificationException
+            // but we never had such bug report in 8 years (since r2263)
             if (!this.remove(o)) {
                 return false;