Crash while adding string to initializer list with Clang Code Model

Steps to reproduce:
1. Print `std::list<std::string>

;`
2. Try to prepend second and third strings: `std::list<std::string>

;`

When I try to open another pair of `"` after `"-o"`, it merges with the first symbol `"` of `"test"`. The QtCreator crashes with assertion:

qtcreator: /home/user/Projects/llvm/include/llvm/ADT/SmallVector.h:140: reference llvm::SmallVectorTemplateCommon<char, void>::operator[](unsigned int) [T = char]: Assertion `begin() + idx < end()' failed.

The full stack-trace in attachment.