ThrowDataException could go screwy if the reader was closed; compensate

Dapper/SqlMapper.cs

@@ -1778,21 +1778,29 @@ static List<FieldInfo> GetSettableFields(Type t)
         /// <param name="reader"></param>
         public static void ThrowDataException(Exception ex, int index, IDataReader reader)
         {
-            string name = "(n/a)", value = "(n/a)";
-            if (reader != null && index >= 0 && index < reader.FieldCount)
+            Exception toThrow;
+            try
             {
-                name = reader.GetName(index);
-                object val = reader.GetValue(index);
-                if (val == null || val is DBNull)
+                string name = "(n/a)", value = "(n/a)";
+                if (reader != null && index >= 0 && index < reader.FieldCount)
                 {
-                    value = "<null>";
-                }
-                else
-                {
-                    value = Convert.ToString(val) + " - " + Type.GetTypeCode(val.GetType());
+                    name = reader.GetName(index);
+                    object val = reader.GetValue(index);
+                    if (val == null || val is DBNull)
+                    {
+                        value = "<null>";
+                    }
+                    else
+                    {
+                        value = Convert.ToString(val) + " - " + Type.GetTypeCode(val.GetType());
+                    }
                 }
+                toThrow = new DataException(string.Format("Error parsing column {0} ({1}={2})", index, name, value), ex);
+            } catch
+            { // throw the **original** exception, wrapped as DataException
+                toThrow = new DataException(ex.Message, ex);   
             }
-            throw new DataException(string.Format("Error parsing column {0} ({1}={2})", index, name, value), ex);
+            throw toThrow;
         }
         private static void EmitInt32(ILGenerator il, int value)
         {

Tests/Program.cs

@@ -111,11 +111,28 @@ insert Posts ([Text],CreationDate, LastChangeDate) values (replicate('x', 2000),
         private static void RunTests()
         {
             var tester = new Tests();
+            int fail = 0;
             foreach (var method in typeof(Tests).GetMethods(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly))
             {
                 Console.Write("Running " + method.Name);
-                method.Invoke(tester, null);
-                Console.WriteLine(" - OK!");
+                try
+                {
+                    method.Invoke(tester, null);
+                    Console.WriteLine(" - OK!");
+                } catch (Exception ex)
+                {
+                    fail++;
+                    Console.WriteLine(" - " + ex.Message);
+                }
+            }
+            Console.WriteLine();
+            if(fail == 0)
+            {
+                Console.WriteLine("(all tests successful)");
+            }
+            else
+            {
+                Console.WriteLine("#### FAILED: {0}", fail);
             }
         }
     }