Index: lib/Format/UnwrappedLineParser.cpp
===================================================================
--- lib/Format/UnwrappedLineParser.cpp
+++ lib/Format/UnwrappedLineParser.cpp
@@ -429,7 +429,7 @@
 
   addUnwrappedLine();
   size_t OpeningLineIndex =
-      Lines.empty() ? (UnwrappedLine::kInvalidIndex) : (Lines.size() - 1);
+      CurrentLines->empty() ? (UnwrappedLine::kInvalidIndex) : (CurrentLines->size() - 1);  //////Lines does not account for 'nested' lines
 
   ScopedDeclarationState DeclarationState(*Line, DeclarationScopeStack,
                                           MustBeDeclaration);