Fix SQL Server dialect paging bug (NH-3138)

The MsSql2005DialectQueryPager was found to be incorrectly identifying
columns in the ORDER BY expression of a query that contains a function
with parameters separated by commas (e.g. "ORDER BY COALESCE(param1,
param2)").

Employed a regular expression for a more sophisticated method of
identifying the columns.

src/NHibernate.Test/NHSpecificTest/NH3138/FixtureByCode.cs

@@ -0,0 +1,65 @@
+using System;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3138
+{
+	[TestFixture]
+	public class FixtureByCode : TestCaseMappingByCode
+	{
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return dialect is Dialect.MsSql2005Dialect;
+		}
+
+		protected override Cfg.MappingSchema.HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Entity>(ca =>
+			{
+				ca.Lazy(false);
+				ca.Id(x => x.Id, map => map.Generator(Generators.GuidComb));
+				ca.Property(x => x.EnglishName);
+				ca.Property(x => x.GermanName);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		[Test]
+		public void PageQueryWithDistinctAndOrderByContainingFunctionWithCommaSeparatedParameters()
+		{
+			using (var session = OpenSession())
+			{
+				Assert.DoesNotThrow(() =>
+					session
+						.CreateQuery("select distinct e.Id, coalesce(e.EnglishName, e.GermanName) from Entity e order by coalesce(e.EnglishName, e.GermanName) asc")
+						.SetFirstResult(10)
+						.SetMaxResults(20)
+						.List<Entity>());
+			}
+		}
+
+		[Test]
+		[Ignore("Failing")]
+		public void PageQueryWithDistinctAndOrderByContainingAliasedFunction()
+		{
+			using (var session = OpenSession())
+			{
+				Assert.DoesNotThrow(() =>
+					session
+						.CreateQuery("select distinct e.Id, coalesce(e.EnglishName, e.GermanName) as LocalizedName from Entity e order by LocalizedName asc")
+						.SetFirstResult(10)
+						.SetMaxResults(20)
+						.List<Entity>());
+			}
+		}
+	}
+
+	class Entity
+	{
+		public Guid Id { get; set; }
+		public string EnglishName { get; set; }
+		public string GermanName { get; set; }
+	}
+}

src/NHibernate.Test/NHibernate.Test.csproj

@@ -963,6 +963,7 @@
     <Compile Include="NHSpecificTest\NH3074\Fixture.cs" />
     <Compile Include="NHSpecificTest\NH3074\Model.cs" />
     <Compile Include="NHSpecificTest\NH3124\FixtureByCode.cs" />
+    <Compile Include="NHSpecificTest\NH3138\FixtureByCode.cs" />
     <Compile Include="NHSpecificTest\NH941\Domain.cs" />
     <Compile Include="NHSpecificTest\NH941\Fixture.cs" />
     <Compile Include="NHSpecificTest\NH941\FixtureUsingList.cs" />

src/NHibernate/Dialect/MsSql2005DialectQueryPager.cs

@@ -67,8 +67,8 @@ private SqlString PageByLimitAndOffset(SqlString offset, SqlString limit)
 			if (orderIndex > 0 && HasMatchingParens(_sourceQuery.Substring(orderIndex).ToString()))
 			{
 				fromAndWhere = _sourceQuery.Substring(fromIndex, orderIndex - fromIndex).Trim();
-				SqlString orderBy = _sourceQuery.Substring(orderIndex).Trim();
-				sortExpressions = orderBy.Substring(9).Split(",");
+				SqlString orderBy = _sourceQuery.Substring(orderIndex).Trim().Substring(9);
+				sortExpressions = orderBy.SplitWithRegex(@"(?<!\([^\)]*),{1}");
 			}
 			else
 			{

src/NHibernate/SqlCommand/SqlString.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 using System.Text;
 using System.Collections;
+using System.Text.RegularExpressions;
 
 namespace NHibernate.SqlCommand
 {
@@ -557,6 +558,11 @@ public SqlString[] Split(string splitter)
 			return SplitParts(splitter).ToArray();
 		}
 
+		internal SqlString[] SplitWithRegex(string pattern)
+		{
+			return Regex.Split(ToString(), pattern).Select(Parse).ToArray();
+		}
+
 		private IEnumerable<SqlString> SplitParts(string splitter)
 		{
 			var startIndex = 0;