[libc] Fix strtok_r crash when src and *saveptr are both nullptr
While working and testing my refactoring of multiple string functions in libc, I came across a bug that needs to be addressed in a patch on its own: src is checked for nullptr and assigned to *saveptr if it is nullptr. However, saveptr is initially nullptr when it comes to reentry. This could cause a problem if both saveptr and src are null; we need to do the check first and return nullptr if both are nullptr.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D106885
GitOrigin-RevId: 0784e62c3c4a4aaabdf29f6fa0b5f8f7598a90d4
2 files changed
