[Debugger] Fix InvalidCastException in MacObjectValueTreeView.OnCopy()

Based on "Find References" on GetRawValue(), it seems that this can
sometimes return RawValueString instead of string. Make sure that
we handle this instead of assuming the value returned by GetRawValue()
is always a string.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1054038/

1 files changed, 12 insertions, 6 deletions

diff --git a/main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/Mac/MacObjectValueTreeView.cs b/main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/Mac/MacObjectValueTreeView.cs
index fa11d2a3f4..ad7ec71480 100644
--- a/main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/Mac/MacObjectValueTreeView.cs
+++ b/main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/ObjectValue/Mac/MacObjectValueTreeView.cs
@@ -32,6 +32,7 @@ using AppKit;
 using Foundation;
 using CoreGraphics;
 
+using Mono.Debugging.Client;
 using Mono.Debugging.Evaluation;
 
 using MonoDevelop.Core;
@@ -778,7 +779,7 @@ namespace MonoDevelop.Debugger
 			if (SelectedRowCount == 0)
 				return;
 
-			var str = new StringBuilder ();
+			var builder = new StringBuilder ();
 			var needsNewLine = false;
 
 			var selectedRows = SelectedRows;
@@ -791,7 +792,7 @@ namespace MonoDevelop.Debugger
 					break;
 
 				if (needsNewLine)
-					str.AppendLine ();
+					builder.AppendLine ();
 
 				needsNewLine = true;
 
@@ -807,22 +808,27 @@ namespace MonoDevelop.Debugger
 							var opt = DebuggerService.Frame.GetStackFrame ().DebuggerSession.Options.EvaluationOptions.Clone ();
 							opt.EllipsizeStrings = false;
 
-							var rawValue = (string) objVal.GetRawValue (opt);
+							var rawValue = objVal.GetRawValue (opt);
+							var str = rawValue as string;
 
-							value = '"' + Mono.Debugging.Evaluation.ExpressionEvaluator.EscapeString (rawValue) + '"';
+							if (str == null && rawValue is RawValueString rawValueString)
+								str = rawValueString.Value;
+
+							if (str != null)
+								value = '"' + ExpressionEvaluator.EscapeString (str) + '"';
 						} catch (EvaluatorException) {
 							// fall back to using the DisplayValue that we would have used anyway...
 						}
 					}
 				}
 
-				str.Append (value);
+				builder.Append (value);
 			}
 
 			var clipboard = NSPasteboard.GeneralPasteboard;
 
 			clipboard.ClearContents ();
-			clipboard.SetStringForType (str.ToString (), NSPasteboard.NSPasteboardTypeString);
+			clipboard.SetStringForType (builder.ToString (), NSPasteboard.NSPasteboardTypeString);
 
 			//Gtk.Clipboard.Get (Gdk.Selection.Clipboard).Text = str.ToString ();
 		}