Fix for ParseTokens

Author: Oleg Nadymov

src/ServiceStack.OrmLite/OrmLiteUtils.cs

@@ -1024,7 +1024,9 @@ public static List<string> ParseTokens(this string expr)
                     if (endPos == -1)
                         endPos = expr.Length;
 
-                    to.Add(expr.Substring(pos, endPos - pos).Trim());
+                    var arg = expr.Substring(pos, endPos - pos).Trim();
+                    if (!string.IsNullOrEmpty(arg))
+                        to.Add(arg);
 
                     pos = endPos;
                     continue;

tests/ServiceStack.OrmLite.Tests/OrmLiteUtilsTests.cs

@@ -0,0 +1,19 @@
+using NUnit.Framework;
+
+namespace ServiceStack.OrmLite.Tests
+{
+    [TestFixture]
+    public class OrmLiteUtilsTests
+        : OrmLiteTestBase
+    {
+        [Test]
+        public void ParseTokens()
+        {
+            var sql =
+                @"(CASE WHEN NOT (((""table_1"".""_display_name"") is null or (""table_1"".""_display_name"") = '')) THEN (""table_1"".""_display_name"") ELSE ""table_1"".""_name"" END) + ""tabel_2"".""_name""";
+            var tokens = OrmLiteUtils.ParseTokens(sql);
+
+            Assert.AreEqual(1,  tokens.Count);
+        }
+    }
+}