Fixed SD2-1312 - DivideByZeroException when searching an empty file. The ForwardTextIterator's MoveAhead method no longer tries to move forward when the text buffer is empty.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.1@2382 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/Base/Project/Src/TextEditor/SearchAndReplace/Engine/TextIterator/ForwardTextIterator.cs

@@ -85,6 +85,10 @@ namespace SearchAndReplace
 			
 			switch (state) {
 				case TextIteratorState.Resetted:
+					if (textBuffer.Length == 0) {
+						state = TextIteratorState.Done;
+						return false;
+					}
 					Position = endOffset;
 					state = TextIteratorState.Iterating;
 					return true;

src/Main/Base/Test/ForwardIteratorWithEmptyTextBufferTestFixture.cs

@@ -0,0 +1,47 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Matthew Ward" email="mrward@users.sourceforge.net"/>
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using ICSharpCode.SharpDevelop.Tests.Utils;
+using ICSharpCode.TextEditor.Document;
+using SearchAndReplace;
+using NUnit.Framework;
+
+namespace ICSharpCode.SharpDevelop.Tests
+{
+	/// <summary>
+	/// The fix for SD2-857 highlighted another bug (SD2-1312) in the 
+	/// ForwardTextIterator where it does not handle the case where
+	/// the ITextBufferStrategy has a length of zero.
+	/// </summary>
+	[TestFixture]
+	public class ForwardIteratorWithEmptyTextBufferTestFixture
+	{
+		ForwardTextIterator forwardTextIterator;
+		
+		[SetUp]
+		public void SetUp()
+		{
+			// Create the document to be iterated through.
+			MockDocument doc = new MockDocument();
+			StringTextBufferStrategy textBufferStrategy = new StringTextBufferStrategy();
+			doc.TextBufferStrategy = textBufferStrategy;
+			ProvidedDocumentInformation docInfo = new ProvidedDocumentInformation(doc, 
+				@"C:\Temp\test.txt", 
+				0);
+			
+			// Create the forward iterator.
+			forwardTextIterator = new ForwardTextIterator(docInfo);
+		}
+		
+		[Test]
+		public void CannotMoveAhead()
+		{
+			Assert.IsFalse(forwardTextIterator.MoveAhead(1));
+		}
+	}
+}

src/Main/Base/Test/ICSharpCode.SharpDevelop.Tests.csproj

@@ -53,6 +53,7 @@
     <Compile Include="CSharpExpressionFinderTests.cs" />
     <Compile Include="ExceptionClassOverridesTestFixture.cs" />
     <Compile Include="FindNextWithCursorAtEndTestFixture.cs" />
+    <Compile Include="ForwardIteratorWithEmptyTextBufferTestFixture.cs" />
     <Compile Include="ForwardTextIteratorPositionIsEndOffsetTestFixture.cs" />
     <Compile Include="NRefactoryResolverTests.cs" />
     <Compile Include="CollectionClassOverridesTestFixture.cs" />