[Debugger] Fixed the saving/restoring of watch expressions between sessions

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/998214/

Author: jstedfast

main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValuePad.cs

@@ -50,13 +50,16 @@ public class ObjectValuePad : PadContent
 		StackFrame lastFrame;
 		bool needsUpdateValues;
 		bool needsUpdateFrame;
-		bool initialResume;
 		bool disposed;
 
 		public override Control Control {
 			get { return control; }
 		}
 
+		protected bool IsInitialResume {
+			get; private set;
+		}
+
 		public ObjectValuePad (bool allowWatchExpressions = false)
 		{
 			if (UseNewTreeView) {
@@ -140,7 +143,7 @@ public ObjectValuePad (bool allowWatchExpressions = false)
 			needsUpdateFrame = true;
 
 			//If pad is created/opened while debugging...
-			initialResume = !DebuggingService.IsDebugging;
+			IsInitialResume = !DebuggingService.IsDebugging;
 		}
 
 		public override void Dispose ()
@@ -222,20 +225,20 @@ protected virtual void OnDebuggerPaused (object s, EventArgs a)
 		protected virtual void OnDebuggerResumed (object s, EventArgs a)
 		{
 			if (UseNewTreeView) {
-				if (!initialResume) {
+				if (!IsInitialResume) {
 					controller.ChangeCheckpoint ();
 				}
 
 				controller.ClearValues ();
 			} else {
-				if (!initialResume) {
+				if (!IsInitialResume) {
 					tree.ChangeCheckpoint ();
 				}
 
 				tree.ClearValues ();
 			}
 
-			initialResume = false;
+			IsInitialResume = false;
 		}
 
 		protected virtual void OnDebuggerStopped (object s, EventArgs a)
@@ -252,7 +255,7 @@ protected virtual void OnDebuggerStopped (object s, EventArgs a)
 			}
 
 			lastFrame = null;
-			initialResume = true;
+			IsInitialResume = true;
 		}
 
 		protected virtual void OnEvaluationOptionsChanged (object s, EventArgs a)

main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/WatchPad.cs

@@ -80,12 +80,14 @@ public void AddWatch (string expression)
 			}
 		}
 
-		void ReloadValues ()
+		void SaveExpressions ()
 		{
-			// clone the list of expressions
 			expressions.Clear ();
 			expressions.AddRange (controller.GetExpressions ());
+		}
 
+		void RestoreExpressions ()
+		{
 			// remove the expressions because we're going to rebuild them
 			controller.ClearAll ();
 
@@ -98,15 +100,15 @@ public override void OnUpdateFrame ()
 			base.OnUpdateFrame ();
 
 			if (UseNewTreeView)
-				ReloadValues ();
+				RestoreExpressions ();
 		}
 
 		public override void OnUpdateValues ()
 		{
 			base.OnUpdateValues ();
 
 			if (UseNewTreeView) {
-				ReloadValues ();
+				RestoreExpressions ();
 			} else {
 				tree.Update ();
 			}
@@ -116,14 +118,22 @@ protected override void OnDebuggerResumed (object s, EventArgs a)
 		{
 			// base will clear the controller, which removes all values and expressions
 
-			if (UseNewTreeView) {
-				expressions.Clear ();
-				expressions.AddRange (controller.GetExpressions ());
-			}
+			if (UseNewTreeView && !IsInitialResume)
+				SaveExpressions ();
 
 			base.OnDebuggerResumed (s, a);
 		}
 
+		protected override void OnDebuggerStopped (object s, EventArgs a)
+		{
+			// base will clear the controller, which removes all values and expressions
+
+			if (UseNewTreeView)
+				SaveExpressions ();
+
+			base.OnDebuggerStopped (s, a);
+		}
+
 		#region IMementoCapable implementation 
 
 		public ICustomXmlSerializer Memento {
@@ -132,10 +142,8 @@ public ICustomXmlSerializer Memento {
 			}
 			set {
 				if (UseNewTreeView) {
-					if (controller != null) {
-						controller.ClearAll ();
-						controller.AddExpressions (expressions);
-					}
+					if (controller != null)
+						RestoreExpressions ();
 				} else {
 					if (tree != null) {
 						tree.ClearExpressions ();
@@ -150,7 +158,7 @@ void ICustomXmlSerializer.WriteTo (XmlWriter writer)
 			if (UseNewTreeView) {
 				if (controller != null) {
 					writer.WriteStartElement ("Values");
-					foreach (var expression in controller.GetExpressions())
+					foreach (var expression in expressions)
 						writer.WriteElementString ("Value", expression);
 					writer.WriteEndElement ();
 				}