fix quirks in XML completion

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/SharpDevelopCompletionWindow.cs

@@ -123,6 +123,9 @@ namespace ICSharpCode.AvalonEdit.AddIn
 						case CompletionItemListKeyResult.InsertionKey:
 							this.CompletionList.RequestInsertion(e);
 							return;
+						case CompletionItemListKeyResult.Cancel:
+							Close();
+							return;
 					}
 				}
 			}

src/AddIns/DisplayBindings/XmlEditor/Project/Src/XmlCodeCompletionBinding.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.XmlEditor
 			this.schemas = schemaFileAssociations.Schemas;
 		}
 		
-		char[] ignoredChars = new[] { '\\', '/', '"', '\'', '=', '>' };
+		char[] ignoredChars = new[] { '\\', '/', '"', '\'', '=', '>', '!', '?' };
 		
 		public CodeCompletionKeyPressResult HandleKeyPress(ITextEditor editor, char ch)
 		{
@@ -70,6 +70,14 @@ namespace ICSharpCode.XmlEditor
 		
 		public bool CtrlSpace(ITextEditor editor)
 		{
+			int elementStartIndex = XmlParser.GetActiveElementStartIndex(editor.Document.Text, editor.Caret.Offset);
+			if (elementStartIndex <= -1)
+				return false;
+			if (editor.Document.GetText(elementStartIndex, editor.Document.TextLength >= elementStartIndex + "<!".Length ? "<!".Length : editor.Document.TextLength - elementStartIndex).Equals("<!", StringComparison.OrdinalIgnoreCase))
+				return false;
+			if (editor.Document.GetText(elementStartIndex, editor.Document.TextLength >= elementStartIndex + "<?".Length ? "<?".Length : editor.Document.TextLength - elementStartIndex).Equals("<?", StringComparison.OrdinalIgnoreCase))
+				return false;
+			
 			XmlSchemaCompletion defaultSchema = schemaFileAssociations.GetSchemaCompletion(editor.FileName);
 			
 			XmlCompletionItemCollection completionItems = GetCompletionItems(editor, defaultSchema);

src/AddIns/DisplayBindings/XmlEditor/Project/Src/XmlCompletionItemCollection.cs

@@ -15,7 +15,7 @@ namespace ICSharpCode.XmlEditor
 
 		public XmlCompletionItemCollection()
 		{
-			normalKeys.AddRange(new char[] { ' ', ':', '.', '_' });
+			normalKeys.AddRange(new char[] { ':', '.', '_' });
 		}
 		
 		public XmlCompletionItemCollection(XmlCompletionItemCollection items)
@@ -120,11 +120,12 @@ namespace ICSharpCode.XmlEditor
 		
 		public CompletionItemListKeyResult ProcessInput(char key)
 		{
-			if (char.IsLetterOrDigit(key)) {
+			if (key == '!' || key == '?')
+				return CompletionItemListKeyResult.Cancel;
+			if (char.IsLetterOrDigit(key))
 				return CompletionItemListKeyResult.NormalKey;
-			} else if (normalKeys.Contains(key)) {
+			if (normalKeys.Contains(key))
 				return CompletionItemListKeyResult.NormalKey;
-			}
 			return CompletionItemListKeyResult.InsertionKey;
 		}
 		

src/Main/Base/Project/Src/Editor/CodeCompletion/ICompletionItemList.cs

@@ -60,7 +60,11 @@ namespace ICSharpCode.SharpDevelop.Editor.CodeCompletion
 		/// key. Can be used to insert whitespace (or other characters) in front of the expression
 		/// while the completion window is open.
 		/// </summary>
-		BeforeStartKey
+		BeforeStartKey,
+		/// <summary>
+		/// This key triggers cancellation of completion. The completion window will be closed.
+		/// </summary>
+		Cancel
 	}
 	
 	public class DefaultCompletionItemList : ICompletionItemList