[Bug libstdc++/87787] [9 Regression] runtime error: null pointer passed as argument 2, which is declared to never be null

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87787

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
That would be my recent commit. We will probably need to add if(size!=0) in
front of the call to memmove...