Ensure we don't crash on null fixes.

src/Features/Core/Portable/AddImport/AbstractAddImportCodeFixProvider.cs

@@ -110,7 +110,7 @@ private async Task<ImmutableArray<CodeAction>> GetCodeActionsAsync(CodeFixContex
                             {
                                 cancellationToken.ThrowIfCancellationRequested();
 
-                                var fixData = await reference.GetFixDataAsync(document, node, placeSystemNamespaceFirst, cancellationToken).ConfigureAwait(false);
+                                var fixData = await reference.TryGetFixDataAsync(document, node, placeSystemNamespaceFirst, cancellationToken).ConfigureAwait(false);
                                 var codeAction = TryCreateCodeAction(document, fixData);
 
                                 result.AddIfNotNull(codeAction);
@@ -123,9 +123,13 @@ private async Task<ImmutableArray<CodeAction>> GetCodeActionsAsync(CodeFixContex
             return result.ToImmutableAndFree();
         }
 
-        private CodeAction TryCreateCodeAction(
-            Document document, AddImportFixData fixData)
+        private CodeAction TryCreateCodeAction(Document document, AddImportFixData fixData)
         {
+            if (fixData == null)
+            {
+                return null;
+            }
+
             switch (fixData.Kind)
             {
                 case AddImportFixKind.ProjectSymbol:

src/Features/Core/Portable/AddImport/References/AssemblyReference.cs

@@ -22,7 +22,7 @@ private partial class AssemblyReference : Reference
                 _referenceAssemblyWithType = referenceAssemblyWithType;
             }
 
-            public override async Task<AddImportFixData> GetFixDataAsync(
+            public override async Task<AddImportFixData> TryGetFixDataAsync(
                 Document document, SyntaxNode node, bool placeSystemNamespaceFirst, CancellationToken cancellationToken)
             {
                 var textChanges = await GetTextChangesAsync(

src/Features/Core/Portable/AddImport/References/PackageReference.cs

@@ -27,7 +27,7 @@ private partial class PackageReference : Reference
                 _versionOpt = versionOpt;
             }
 
-            public override async Task<AddImportFixData> GetFixDataAsync(
+            public override async Task<AddImportFixData> TryGetFixDataAsync(
                 Document document, SyntaxNode node, bool placeSystemNamespaceFirst, CancellationToken cancellationToken)
             {
                 var textChanges = await GetTextChangesAsync(

src/Features/Core/Portable/AddImport/References/Reference.cs

@@ -117,7 +117,7 @@ public override int GetHashCode()
                 return (newContextNode, newDocument);
             }
 
-            public abstract Task<AddImportFixData> GetFixDataAsync(
+            public abstract Task<AddImportFixData> TryGetFixDataAsync(
                 Document document, SyntaxNode node, bool placeSystemNamespaceFirst, CancellationToken cancellationToken);
 
             protected async Task<ImmutableArray<TextChange>> GetTextChangesAsync(

src/Features/Core/Portable/AddImport/References/SymbolReference.cs

@@ -71,7 +71,7 @@ public override int GetHashCode()
                 return textChanges.ToImmutableArray();
             }
 
-            public sealed override async Task<AddImportFixData> GetFixDataAsync(
+            public sealed override async Task<AddImportFixData> TryGetFixDataAsync(
                 Document document, SyntaxNode node,
                 bool placeSystemNamespaceFirst, CancellationToken cancellationToken)
             {