dispose unneeded AXml data after parsing files without IViewContent

src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlParser.cs

@@ -104,6 +104,21 @@ namespace ICSharpCode.XamlBinding
 				return visitor.CompilationUnit;
 			}
 			//}
+			// During project load all XAML files are parsed
+			// most of them are not opened, thus fileContent.Version is null.
+			// We can clear the parser data, because the file will be reparsed
+			// as soon as it is opened by the user.
+			
+			// This will save us some memory, because we only use the
+			// compilation unit created by the visitor above for code completion.
+			if (fileContent.Version == null) {
+				parser.Lock.EnterWriteLock();
+				// double-checked locking (other threads might parse the document in the meantime)
+				if (lastParsedVersion == null) {
+					parser.Clear();
+				}
+				parser.Lock.ExitWriteLock();
+			}
 		}
 		
 		/// <summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/AXmlParser.cs

@@ -97,15 +97,8 @@ namespace ICSharpCode.AvalonEdit.Xml
 		/// <summary> Create new parser </summary>
 		public AXmlParser()
 		{
-			this.UnknownEntityReferenceIsError = true;
-			this.TrackedSegments = new TrackedSegmentCollection();
 			this.Lock = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
-			
-			this.userDocument = new AXmlDocument() { Parser = this };
-			this.userDocument.Document = this.userDocument;
-			// Track the document
-			this.TrackedSegments.AddParsedObject(this.userDocument, null);
-			this.userDocument.IsCached = false;
+			ClearInternal();
 		}
 		
 		/// <summary> Throws exception if condition is false </summary>
@@ -181,5 +174,24 @@ namespace ICSharpCode.AvalonEdit.Xml
 				return userDocument;
 			}
 		}
+		
+		public void Clear()
+		{
+			if (!Lock.IsWriteLockHeld)
+				throw new InvalidOperationException("Write lock needed!");
+			
+			ClearInternal();
+		}
+		
+		void ClearInternal()
+		{
+			this.UnknownEntityReferenceIsError = true;
+			this.TrackedSegments = new TrackedSegmentCollection();
+			this.userDocument = new AXmlDocument() { Parser = this };
+			this.userDocument.Document = this.userDocument;
+			// Track the document
+			this.TrackedSegments.AddParsedObject(this.userDocument, null);
+			this.userDocument.IsCached = false;
+		}
 	}
 }