set content type for AbstractDebuggerIntelliSenseContext to the original content type (#30679)

src/VisualStudio/Core/Def/Implementation/DebuggerIntelliSense/AbstractDebuggerIntelliSenseContext.cs

@@ -25,6 +25,7 @@ internal abstract class AbstractDebuggerIntelliSenseContext : IDisposable
     {
         private readonly IWpfTextView _textView;
         private readonly IContentType _contentType;
+        private readonly IContentType _originalContentType;
         protected readonly IProjectionBufferFactoryService ProjectionBufferFactoryService;
         protected readonly Microsoft.VisualStudio.TextManager.Interop.TextSpan CurrentStatementSpan;
         private readonly IVsTextLines _debuggerTextLines;
@@ -58,6 +59,7 @@ private class ImmediateWindowContext
             this.ContextBuffer = contextBuffer;
             this.CurrentStatementSpan = currentStatementSpan[0];
             _contentType = contentType;
+            _originalContentType = _textView.TextBuffer.ContentType;
             this.ProjectionBufferFactoryService = componentModel.GetService<IProjectionBufferFactoryService>();
             _bufferGraphFactoryService = componentModel.GetService<IBufferGraphFactoryService>();
             _isImmediateWindow = IsImmediateWindow((IVsUIShell)serviceProvider.GetService(typeof(SVsUIShell)), vsTextView);
@@ -200,6 +202,12 @@ internal bool TryInitialize()
             return true;
         }
 
+        internal void SetContentType(bool install)
+        {
+            var contentType = install ? _contentType :_originalContentType;
+            _textView.TextBuffer.ChangeContentType(contentType, null);
+        }
+
         private ITrackingSpan CreateImmediateWindowProjectionMapping(Document document, out ImmediateWindowContext immediateWindowContext)
         {
             var caretLine = _textView.Caret.ContainingTextViewLine.Extent;

src/VisualStudio/Core/Def/Implementation/DebuggerIntelliSense/DebuggerIntellisenseFilter.cs

@@ -194,6 +194,9 @@ internal void RemoveContext()
             _context = null;
         }
 
+        internal void SetContentType(bool install)
+            => _context?.SetContentType(install);
+
         public void Dispose()
         {
             if (_context != null)

src/VisualStudio/Core/Def/Implementation/LanguageService/AbstractLanguageService`2.IVsImmediateStatementCompletion2.cs

@@ -40,12 +40,7 @@ int IVsImmediateStatementCompletion2.InstallStatementCompletion(int install, IVs
             if (install != 0)
             {
                 DebuggerIntelliSenseFilter<TPackage, TLanguageService> filter;
-                if (this.filters.ContainsKey(textView))
-                {
-                    // We already have a filter in this textview. Return.
-                    return VSConstants.S_OK;
-                }
-                else
+                if (!this.filters.ContainsKey(textView))
                 {
                     filter = new DebuggerIntelliSenseFilter<TPackage, TLanguageService>(this,
                         this.EditorAdaptersFactoryService.GetWpfTextView(textView),
@@ -55,10 +50,13 @@ int IVsImmediateStatementCompletion2.InstallStatementCompletion(int install, IVs
                     Marshal.ThrowExceptionForHR(textView.AddCommandFilter(filter, out var nextFilter));
                     filter.SetNextFilter(nextFilter);
                 }
+
+                this.filters[textView].SetContentType(install: true);
             }
             else
             {
                 Marshal.ThrowExceptionForHR(textView.RemoveCommandFilter(this.filters[textView]));
+                this.filters[textView].SetContentType(install: false);
                 this.filters[textView].Dispose();
                 this.filters.Remove(textView);
             }