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src/Workspaces/Core/Portable/FindSymbols/FindReferences/DependentTypeFinder.cs

@@ -275,9 +275,12 @@ internal static partial class DependentTypeFinder
 
                         Debug.Assert(foundType.Locations.Any(s_isInMetadata));
 
-                        // Add to the result list.
+                        // This was a good match, add to the final result list.
                         result.Add(foundType);
 
+                        // If we're doing a transitive search, add these found types to the 'current' sets we're
+                        // searching for more results for. These will then be used when searching for more types in the
+                        // next project (which our caller controls).
                         if (transitive && shouldContinueSearching(foundType))
                         {
                             currentMetadataTypes.Add(foundType);