Add suport for converting JAVA_OBJECT to UUID for better Postgres compatibility

h2/src/main/org/h2/value/Value.java

@@ -910,6 +910,14 @@ public abstract class Value {
                 case BYTES:
                     return ValueUuid.get(getBytesNoCopy());
                 case JAVA_OBJECT:
+                    Object object = JdbcUtils.deserialize(getBytesNoCopy(), getDataHandler());
+                    if (object instanceof java.util.UUID) {
+                        java.util.UUID uuid = (java.util.UUID) object;
+                        return ValueUuid.get(uuid.getMostSignificantBits(), uuid.getLeastSignificantBits());
+                    }
+                    else {
+                        throw DbException.get(ErrorCode.DATA_CONVERSION_ERROR_1, getString());
+                    }
                 case TIMESTAMP_TZ:
                     throw DbException.get(
                             ErrorCode.DATA_CONVERSION_ERROR_1, getString());

h2/src/test/org/h2/test/unit/TestValue.java

@@ -285,8 +285,12 @@ public class TestValue extends TestBase {
         ValueUuid min = ValueUuid.get(minHigh, minLow);
         assertEquals("00000000-0000-4000-8000-000000000000", min.getString());
 
-        ValueJavaObject vo = ValueJavaObject.getNoCopy(UUID.randomUUID(), null, null);
-        assertThrows(DbException.class, vo).convertTo(Value.UUID);
+        // Test conversion from ValueJavaObject to ValueUuid
+        ValueJavaObject vo_uuid = ValueJavaObject.getNoCopy(UUID.randomUUID(), null, null);
+        assertTrue(vo_uuid.convertTo(Value.UUID) instanceof ValueUuid);
+
+        ValueJavaObject vo_string = ValueJavaObject.getNoCopy(new String("This is not a ValueUuid object"), null, null);
+        assertThrows(DbException.class, vo_string).convertTo(Value.UUID);
     }
 
     private void testModulusDouble() {