diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ITextSource.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ITextSource.cs
index 42bdc4f5c5..5f25b65e99 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ITextSource.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ITextSource.cs
@@ -78,6 +78,7 @@ namespace ICSharpCode.AvalonEdit.Document
 	/// Implements the ITextSource interface by wrapping another TextSource
 	/// and viewing only a part of the text.
 	/// </summary>
+	[Obsolete("This class will be removed in a future version of AvalonEdit")]
 	public sealed class TextSourceView : ITextSource
 	{
 		readonly ITextSource baseTextSource;
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/TextUtilities.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/TextUtilities.cs
index 17ec1f309a..ad3389c3fb 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/TextUtilities.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/TextUtilities.cs
@@ -243,8 +243,8 @@ namespace ICSharpCode.AvalonEdit.Document
 		/// in the text source.</returns>
 		/// <remarks>
 		/// This method is NOT equivalent to the actual caret movement when using VisualLine.GetNextCaretPosition.
-		/// In real caret movement, there are additional caret stops at line starts and ends. However, this method
-		/// doesn't know anything about lines: it is often called with a textSource that represents only a single VisualTextElement.
+		/// In real caret movement, there are additional caret stops at line starts and ends. This method
+		/// treats linefeeds as simple whitespace.
 		/// </remarks>
 		public static int GetNextCaretPosition(ITextSource textSource, int offset, LogicalDirection direction, CaretPositioningMode mode)
 		{
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/UndoStack.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/UndoStack.cs
index a7a153d4ff..57d9967302 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/UndoStack.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/UndoStack.cs
@@ -22,7 +22,7 @@ namespace ICSharpCode.AvalonEdit.Document
 		Deque<IUndoableOperation> undostack = new Deque<IUndoableOperation>();
 		Deque<IUndoableOperation> redostack = new Deque<IUndoableOperation>();
 		
-		int sizeLimit = 1000;
+		int sizeLimit = int.MaxValue;
 		bool acceptChanges = true;
 		
 		/// <summary>
@@ -51,7 +51,6 @@ namespace ICSharpCode.AvalonEdit.Document
 		
 		/// <summary>
 		/// Gets/Sets the limit on the number of items on the undo stack.
-		/// The default value is 1000.
 		/// </summary>
 		/// <remarks>The size limit is enforced only on the number of stored top-level undo groups.
 		/// Elements within undo groups do not count towards the size limit.</remarks>
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
index c61394b326..eae09fe65a 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
@@ -52,6 +52,16 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// </summary>
 		public ReadOnlyCollection<TextLine> TextLines { get; private set; }
 		
+		/// <summary>
+		/// Gets the start offset of the VisualLine inside the document.
+		/// This is equivalent to <c>FirstDocumentLine.Offset</c>.
+		/// </summary>
+		public int StartOffset { 
+			get {
+				return FirstDocumentLine.Offset;
+			}
+		}
+		
 		/// <summary>
 		/// Length in visual line coordinates.
 		/// </summary>
@@ -334,7 +344,7 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			if (direction == LogicalDirection.Backward) {
 				// Search Backwards:
 				// If the last element doesn't handle line borders, return the line end as caret stop
-				// (we don't check the mode here: we treat a line end as word start, border, etc.
+				
 				if (visualColumn > this.VisualLength && !elements[elements.Count-1].HandlesLineBorders && HasImplicitStopAtLineEnd(mode)) {
 					return this.VisualLength;
 				}
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLineText.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLineText.cs
index ed909c010a..b4876d6889 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLineText.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLineText.cs
@@ -90,21 +90,18 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// <inheritdoc/>
 		public override int GetVisualColumn(int relativeTextOffset)
 		{
-			return VisualColumn + relativeTextOffset - this.RelativeTextOffset;
+			return this.VisualColumn + relativeTextOffset - this.RelativeTextOffset;
 		}
 		
 		/// <inheritdoc/>
 		public override int GetNextCaretPosition(int visualColumn, LogicalDirection direction, CaretPositioningMode mode)
 		{
-			int textOffset = parentVisualLine.FirstDocumentLine.Offset + this.RelativeTextOffset;
-			TextSourceView view = new TextSourceView(
-				parentVisualLine.Document,
-				new SimpleSegment(textOffset, this.DocumentLength));
-			int pos = TextUtilities.GetNextCaretPosition(view, visualColumn - this.VisualColumn, direction, mode);
-			if (pos < 0)
-				return pos;
+			int textOffset = parentVisualLine.StartOffset + this.RelativeTextOffset;
+			int pos = TextUtilities.GetNextCaretPosition(parentVisualLine.Document, textOffset + visualColumn - this.VisualColumn, direction, mode);
+			if (pos < textOffset || pos > textOffset + this.DocumentLength)
+				return -1;
 			else
-				return this.VisualColumn + pos;
+				return this.VisualColumn + pos - textOffset;
 		}
 	}
 }
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/Deque.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/Deque.cs
index e249378d2e..8b108ef163 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/Deque.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/Deque.cs
@@ -15,6 +15,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 	/// Double-ended queue.
 	/// </summary>
 	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
+	[Serializable]
 	public class Deque<T> : ICollection<T>
 	{
 		T[] arr = Empty<T>.Array;