Index: trunk/test/unit/org/openstreetmap/josm/data/projection/ProjectionRefTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/projection/ProjectionRefTest.java	(revision 4277)
+++ trunk/test/unit/org/openstreetmap/josm/data/projection/ProjectionRefTest.java	(revision 4277)
@@ -0,0 +1,111 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.projection;
+
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map.Entry;
+
+import org.junit.Test;
+import org.openstreetmap.josm.data.coor.EastNorth;
+import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.tools.Utils;
+
+/**
+ * Test projections using reference data. (Currently provided by proj.4)
+ * 
+ * The data file data_nodist/projection-reference-data.csv can be created like this:
+ *      Fist run this file's main method to collect epsg codes and bounds data.
+ *      Then pipe the result into test/generate-proj-data.pl.
+ */
+public class ProjectionRefTest {
+
+    /**
+     * create a list of epsg codes and bounds to be used by
+     * @param args
+     */
+    public static void main(String[] args) {
+        HashMap<String, Projection> allCodes = new LinkedHashMap<String, Projection>();
+        List<Projection> projs = Projections.getProjections();
+        for (Projection p: projs) {
+            if (p instanceof ProjectionSubPrefs) {
+                for (String code : ((ProjectionSubPrefs)p).allCodes()) {
+                    ProjectionSubPrefs projSub = recreateProj((ProjectionSubPrefs)p);
+                    Collection<String> prefs = projSub.getPreferencesFromCode(code);
+                    projSub.setPreferences(prefs);
+                    allCodes.put(code, projSub);
+                }
+            } else {
+                allCodes.put(p.toCode(), p);
+            }
+        }
+        for (Entry<String, Projection> e : allCodes.entrySet()) {
+            System.out.println(String.format("%s %s", e.getKey(), e.getValue().getWorldBoundsLatLon()));
+        }
+    }
+
+    private static ProjectionSubPrefs recreateProj(ProjectionSubPrefs proj) {
+        try {
+            return proj.getClass().newInstance();
+        } catch (Exception e) {
+            throw new IllegalStateException(
+                    tr("Cannot instantiate projection ''{0}''", proj.getClass().toString()), e);
+        }
+    }
+
+    @Test
+    public void test() throws IOException, FileNotFoundException {
+        BufferedReader in = new BufferedReader(new FileReader("data_nodist/projection-reference-data.csv"));
+        StringBuilder fail = new StringBuilder();
+        String line;
+        while ((line = in.readLine()) != null) {
+            if (line.startsWith("#")) {
+                continue;
+            }
+            String[] f = line.split(",");
+            String code = f[0];
+            double lat = Double.parseDouble(f[1]);
+            double lon = Double.parseDouble(f[2]);
+            double east = Double.parseDouble(f[3]);
+            double north = Double.parseDouble(f[4]);
+            Projection p = ProjectionInfo.getProjectionByCode(code);
+            {
+                EastNorth en = p.latlon2eastNorth(new LatLon(lat, lon));
+                String error = String.format("%s (%s): Projecting latlon(%s,%s):\n" +
+                        "        expected: eastnorth(%s,%s),\n" +
+                        "        but got:  eastnorth(%s,%s)!\n",
+                        p.toString(), code, lat, lon, east, north, en.east(), en.north());
+                double EPSILON = 1e-3; // 1 mm accuracy
+                if (Math.abs(east - en.east()) > EPSILON || Math.abs(north - en.north()) > EPSILON) {
+                    fail.append(error);
+                }
+            }
+            {
+                LatLon ll = p.eastNorth2latlon(new EastNorth(east, north));
+                String error = String.format("%s (%s): Inverse projecting eastnorth(%s,%s):\n" +
+                        "        expected: latlon(%s,%s),\n" +
+                        "        but got:  latlon(%s,%s)!\n",
+                        p.toString(), code, east, north, lat, lon, ll.lat(), ll.lon());
+                double EPSILON = Math.toDegrees(1e-3 / 6378137); // 1 mm accuracy (or better)
+                if (Math.abs(lat - ll.lat()) > EPSILON || Math.abs(lon - ll.lon()) > EPSILON) {
+                    if (!("yes".equals(System.getProperty("suppressPermanentFailure")) && code.equals("EPSG:21781"))) {
+                        fail.append(error);
+                    }
+                }
+            }
+        }
+        Utils.close(in);
+        if (fail.length() > 0) {
+            System.err.println(fail.toString());
+            throw new AssertionError(fail.toString());
+        }
+
+    }
+}