Add IsDeleted and Equals() implementation to IDocumentLine.

ICSharpCode.NRefactory/Editor/IDocumentLine.cs

@@ -51,5 +51,10 @@ namespace ICSharpCode.NRefactory.Editor
 		/// Gets the next line. Returns null if this is the last line in the document.
 		/// </summary>
 		IDocumentLine NextLine { get; }
+		
+		/// <summary>
+		/// Gets whether the line was deleted.
+		/// </summary>
+		bool IsDeleted { get; }
 	}
 }

ICSharpCode.NRefactory/Editor/ReadOnlyDocument.cs

@@ -84,6 +84,17 @@ namespace ICSharpCode.NRefactory.Editor
 				this.endOffset = doc.GetEndOffset(lineNumber);
 			}
 			
+			public override int GetHashCode()
+			{
+				return doc.GetHashCode() ^ lineNumber;
+			}
+			
+			public override bool Equals(object obj)
+			{
+				ReadOnlyDocumentLine other = obj as ReadOnlyDocumentLine;
+				return other != null && doc == other.doc && lineNumber == other.lineNumber;
+			}
+			
 			public int Offset {
 				get { return offset; }
 			}
@@ -129,6 +140,10 @@ namespace ICSharpCode.NRefactory.Editor
 						return new ReadOnlyDocumentLine(doc, lineNumber + 1);
 				}
 			}
+			
+			public bool IsDeleted {
+				get { return false; }
+			}
 		}
 		
 		int GetStartOffset(int lineNumber)