[Bug libstdc++/118035] deque bug when inserting an empty iterator interval

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118035

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We can call it a regression, since this C++98 version used to work correctly
and now doesn't:

#include <deque>
#include <iostream>
#include <vector>

using namespace std;

int main() {
  deque<string> my_deque;
  my_deque.push_back("one");
  my_deque.push_back("two");
  my_deque.push_back("three");
  vector<string> v;
  my_deque.insert(my_deque.begin() + 1, v.begin(), v.end());
  for (deque<string>::iterator i = my_deque.begin(), end = my_deque.end();
      i != end; ++i)
    cout << *i << endl;
}