Index: /trunk/src/org/openstreetmap/josm/Main.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/Main.java	(revision 2986)
+++ /trunk/src/org/openstreetmap/josm/Main.java	(revision 2987)
@@ -155,4 +155,10 @@
 
     /**
+     * Wheather or not the java vm is openjdk
+     * We use this to work around openjdk bugs
+     */
+    public static boolean isOpenjdk;
+
+    /**
      * Set or clear (if passed <code>null</code>) the map.
      */
@@ -190,5 +196,5 @@
     public Main() {
         main = this;
-        //        platform = determinePlatformHook();
+        isOpenjdk = System.getProperty("java.vm.name").toUpperCase().indexOf("OPENJDK") != -1;
         platform.startupHook();
         contentPane.add(panel, BorderLayout.CENTER);
Index: /trunk/src/org/openstreetmap/josm/actions/ShowStatusReportAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/ShowStatusReportAction.java	(revision 2986)
+++ /trunk/src/org/openstreetmap/josm/actions/ShowStatusReportAction.java	(revision 2987)
@@ -59,5 +59,7 @@
         text.append(" MB allocated, but free)");
         text.append("\n");
-        text.append("Java version: " + System.getProperty("java.version") + ", " + System.getProperty("java.vendor") + ", " + System.getProperty("os.name"));
+        text.append("Java version: " + System.getProperty("java.version") + ", " + System.getProperty("java.vendor") + ", " + System.getProperty("java.vm.name"));
+        text.append("\n");
+        text.append("Operating system: "+ System.getProperty("os.name"));
         text.append("\n\n");
         DataSet dataset = Main.main.getCurrentDataSet();
Index: /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/LineClip.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/LineClip.java	(revision 2987)
+++ /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/LineClip.java	(revision 2987)
@@ -0,0 +1,105 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.osm.visitor.paint;
+
+import static java.awt.geom.Rectangle2D.OUT_LEFT;
+import static java.awt.geom.Rectangle2D.OUT_RIGHT;
+import static java.awt.geom.Rectangle2D.OUT_TOP;
+import static java.awt.geom.Rectangle2D.OUT_BOTTOM;
+import java.awt.Point;
+
+/**
+ * Computes the part of a line that is visible in a given rectangle.
+ * Using int leads to overflow, so we need long int.
+ * http://en.wikipedia.org/wiki/Cohen-Sutherland
+ */
+public class LineClip {
+    private Point p1, p2;
+
+    /**
+     * The outcode of the point.
+     * We cannot use Rectangle.outcode since it does not work with long ints.
+     */
+    public int computeOutCode (long x, long y, long xmin, long ymin, long xmax, long ymax) {
+        int code = 0;
+        if (y > ymax) {
+            code |= OUT_TOP;
+        }
+        else if (y < ymin) {
+            code |= OUT_BOTTOM;
+        }
+        if (x > xmax) {
+            code |= OUT_RIGHT;
+        }
+        else if (x < xmin) {
+            code |= OUT_LEFT;
+        }
+        return code;
+    }
+
+    public boolean cohenSutherland( long x1, long y1, long x2, long y2, long xmin, long ymin, long xmax, long ymax)
+    {
+        int outcode0, outcode1, outcodeOut;
+        boolean accept = false;
+        boolean done = false;
+
+        outcode0 = computeOutCode (x1, y1, xmin, ymin, xmax, ymax);
+        outcode1 = computeOutCode (x2, y2, xmin, ymin, xmax, ymax);
+
+        do {
+            if ((outcode0 | outcode1) == 0 ) {
+                accept = true;
+                done = true;
+            }
+            else if ( (outcode0 & outcode1) > 0 ) {
+                done = true;
+            }
+            else {
+                long x = 0, y = 0;
+                outcodeOut = outcode0 != 0 ? outcode0: outcode1;
+                if ( (outcodeOut & OUT_TOP) > 0 ) {
+                    x = x1 + (x2 - x1) * (ymax - y1)/(y2 - y1);
+                    y = ymax;
+                }
+                else if ((outcodeOut & OUT_BOTTOM) > 0 ) {
+                    x = x1 + (x2 - x1) * (ymin - y1)/(y2 - y1);
+                    y = ymin;
+                }
+                else if ((outcodeOut & OUT_RIGHT)> 0) {
+                    y = y1 + (y2 - y1) * (xmax - x1)/(x2 - x1);
+                    x = xmax;
+                }
+                else if ((outcodeOut & OUT_LEFT) > 0) {
+                    y = y1 + (y2 - y1) * (xmin - x1)/(x2 - x1);
+                    x = xmin;
+                }
+                if (outcodeOut == outcode0) {
+                    x1 = x;
+                    y1 = y;
+                    outcode0 = computeOutCode(x1, y1, xmin, ymin, xmax, ymax);
+                } else {
+                    x2 = x;
+                    y2 = y;
+                    outcode1 = computeOutCode(x2, y2, xmin, ymin, xmax, ymax);
+                }
+            }
+        }
+        while (!done);
+
+        if(accept) {
+            p1 = new Point((int) x1, (int) y1);
+            p2 = new Point((int) x2, (int) y2);
+            return true;
+        }
+        return false;
+    }
+
+    public Point getP1()
+    {
+        return p1;
+    }
+
+    public Point getP2()
+    {
+        return p2;
+    }
+}
Index: /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/MapPainter.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/MapPainter.java	(revision 2986)
+++ /trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/MapPainter.java	(revision 2987)
@@ -131,6 +131,20 @@
 
     private void drawSegment(GeneralPath path, Point p1, Point p2, boolean showDirection, boolean reversedDirection) {
-        if (isSegmentVisible(p1, p2)) {
-
+        boolean drawIt = false;
+        if (Main.isOpenjdk) {
+            /**
+             * Work around openjdk bug. It leads to drawing artefacts when zooming in a lot. (#4289, #4424)
+             * (It looks like int overflow when clipping.) We do custom clipping.
+             */
+            Rectangle bounds = g.getClipBounds();
+            bounds.grow(100, 100);                  // avoid arrow heads at the border
+            LineClip clip = new LineClip();
+            drawIt = clip.cohenSutherland(p1.x, p1.y, p2.x, p2.y, bounds.x, bounds.y, bounds.x+bounds.width, bounds.y+bounds.height);
+            p1 = clip.getP1();
+            p2 = clip.getP2();
+        } else {
+            drawIt = isSegmentVisible(p1, p2);
+        }
+        if (drawIt) {
             /* draw segment line */
             path.moveTo(p1.x, p1.y);