diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ILineTracker.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ILineTracker.cs
index 0b99f61e64..c1d7a0a3da 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ILineTracker.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/ILineTracker.cs
@@ -32,6 +32,9 @@ namespace ICSharpCode.AvalonEdit.Document
 		
 		/// <summary>
 		/// Is called immediately before a document line changes length.
+		/// This method will be called whenever the line is changed, even when the length stays as it is.
+		/// The method might be called multiple times for a single line because
+		/// a replacement is internally handled as removal followed by insertion.
 		/// </summary>
 		void SetLineLength(DocumentLine line, int newTotalLength);
 		
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/InlineObjectRun.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/InlineObjectRun.cs
index 29ea4b73a6..9ab6419f32 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/InlineObjectRun.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/InlineObjectRun.cs
@@ -43,6 +43,8 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				throw new ArgumentNullException("context");
 			
 			// remove inline object if its already added, can happen e.g. when recreating textrun for word-wrapping
+			// TODO: certainly the text view should handle this internally? external code might want to use InlineObjectRun,
+			// but doesn't have access to textLayer.RemoveInlineObject
 			context.TextView.textLayer.RemoveInlineObject(this.Element);
 			
 			return new InlineObjectRun(1, this.TextRunProperties, this.Element);