Index: trunk/src/org/openstreetmap/josm/tools/ImageProvider.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/ImageProvider.java	(revision 10139)
+++ trunk/src/org/openstreetmap/josm/tools/ImageProvider.java	(revision 10140)
@@ -83,4 +83,5 @@
 import com.kitfox.svg.SVGDiagram;
 import com.kitfox.svg.SVGUniverse;
+import org.openstreetmap.josm.data.osm.DataSet;
 
 /**
@@ -1312,5 +1313,16 @@
         // Check if the current styles have special icon for tagged nodes.
         if (primitive instanceof org.openstreetmap.josm.data.osm.Node) {
-            Pair<StyleElementList, Range> nodeStyles = MapPaintStyles.getStyles().generateStyles(primitive, 100, false);
+            Pair<StyleElementList, Range> nodeStyles;
+            DataSet ds = primitive.getDataSet();
+            if (ds != null) {
+                ds.getReadLock().lock();
+            }
+            try {
+                nodeStyles = MapPaintStyles.getStyles().generateStyles(primitive, 100, false);
+            } finally {
+                if (ds != null) {
+                    ds.getReadLock().unlock();
+                }
+            }
             for (StyleElement style : nodeStyles.a) {
                 if (style instanceof NodeElement) {