Merge pull request #5434 from KevinH-MS/master

Add null checks when calling IWpfTextView.TextViewModel...

src/VisualStudio/Core/Def/Implementation/Snippets/AbstractSnippetExpansionClient.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -365,6 +366,13 @@ public virtual bool TryHandleReturn()
 
         public virtual bool TryInsertExpansion(int startPositionInSubjectBuffer, int endPositionInSubjectBuffer)
         {
+            var textViewModel = TextView.TextViewModel;
+            if (textViewModel == null)
+            {
+                Debug.Assert(TextView.IsClosed);
+                return false;
+            }
+
             int startLine = 0;
             int startIndex = 0;
             int endLine = 0;
@@ -377,13 +385,13 @@ public virtual bool TryInsertExpansion(int startPositionInSubjectBuffer, int end
             SnapshotSpan dataBufferSpan;
             if (!TryGetSpanOnHigherBuffer(
                 SubjectBuffer.CurrentSnapshot.GetSpan(startPositionInSubjectBuffer, endPositionInSubjectBuffer - startPositionInSubjectBuffer),
-                TextView.TextViewModel.DataBuffer,
+                textViewModel.DataBuffer,
                 out dataBufferSpan))
             {
                 return false;
             }
 
-            var buffer = EditorAdaptersFactoryService.GetBufferAdapter(TextView.TextViewModel.DataBuffer);
+            var buffer = EditorAdaptersFactoryService.GetBufferAdapter(textViewModel.DataBuffer);
             var expansion = buffer as IVsExpansion;
             if (buffer == null || expansion == null)
             {
@@ -446,6 +454,13 @@ public int OnBeforeInsertion(IVsExpansionSession pSession)
 
         public int OnItemChosen(string pszTitle, string pszPath)
         {
+            var textViewModel = TextView.TextViewModel;
+            if (textViewModel == null)
+            {
+                Debug.Assert(TextView.IsClosed);
+                return VSConstants.E_FAIL;
+            }
+
             var hr = VSConstants.S_OK;
 
             try
@@ -456,7 +471,7 @@ public int OnItemChosen(string pszTitle, string pszPath)
                 textSpan.iEndLine = textSpan.iStartLine;
                 textSpan.iEndIndex = textSpan.iStartIndex;
 
-                IVsExpansion expansion = EditorAdaptersFactoryService.GetBufferAdapter(TextView.TextViewModel.DataBuffer) as IVsExpansion;
+                IVsExpansion expansion = EditorAdaptersFactoryService.GetBufferAdapter(textViewModel.DataBuffer) as IVsExpansion;
                 earlyEndExpansionHappened = false;
                 hr = expansion.InsertNamedExpansion(pszTitle, pszPath, textSpan, this, LanguageServiceGuid, fShowDisambiguationUI: 0, pSession: out ExpansionSession);
 

src/VisualStudio/Core/Def/Implementation/Venus/VenusCommandFilter.cs

@@ -53,12 +53,20 @@ public override int GetDataTipText(TextSpan[] pSpan, out string pbstrText)
                 return VSConstants.E_INVALIDARG;
             }
 
+            var textViewModel = WpfTextView.TextViewModel;
+            if (textViewModel == null)
+            {
+                Debug.Assert(WpfTextView.IsClosed);
+                pbstrText = null;
+                return VSConstants.E_FAIL;
+            }
+
             // We need to map the TextSpan from the DataBuffer to our subject buffer. We'll
             // only consider spans whose length matches our input span (which we expect to
             // always be zero). This is to address the case where the position is on a seam
             // and maps to multiple source spans.
             // If there is not exactly one matching span, just return.
-            var span = WpfTextView.TextViewModel.DataBuffer.CurrentSnapshot.GetSpan(pSpan[0]);
+            var span = textViewModel.DataBuffer.CurrentSnapshot.GetSpan(pSpan[0]);
             var spanLength = span.Length;
             Debug.Assert(spanLength == 0, $"Expected zero length span (got '{spanLength}'.");
             var subjectSpan = WpfTextView.BufferGraph.MapDownToBuffer(span, SpanTrackingMode.EdgeInclusive, _subjectBuffer)
@@ -83,7 +91,7 @@ public override int GetDataTipText(TextSpan[] pSpan, out string pbstrText)
                 // take the span that intersects with the input span, since that's probably
                 // the one we care about.
                 // If there are no such spans, just return.
-                var surfaceSpan = WpfTextView.BufferGraph.MapUpToBuffer(subjectSpan, SpanTrackingMode.EdgeInclusive, WpfTextView.TextViewModel.DataBuffer)
+                var surfaceSpan = WpfTextView.BufferGraph.MapUpToBuffer(subjectSpan, SpanTrackingMode.EdgeInclusive, textViewModel.DataBuffer)
                                     .SingleOrDefault(x => x.IntersectsWith(span));
 
                 if (surfaceSpan == default(SnapshotSpan))