Add a missing debug assertion in <list>

[• Quuxplusone]

Summary

This came up in D100595.

[• Quuxplusone]

Just looking for a second libc++ approval at this point.

[curdeius]

LGTM if this will get tested by https://reviews.llvm.org/D100595.

libcxx/include/list

2093

Hmm, would it make sense to add as well a debug check that __p is not in range [__f, __l) (that's a UB)?

[• Quuxplusone]

libcxx/include/list

2093

Perhaps, but I don't think we have any such assertions at the moment, and that would need a new test; so I'm deferring it to a separate PR (and probably a separate programmer :))

libcxx/include/list

             __db->unlock();
         }
 #endif
     }
 }
 
 template <class _Tp, class _Alloc>
 void
 list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l)
 {
 #if _LIBCPP_DEBUG_LEVEL == 2
     _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
         "list::splice(iterator, list, iterator, iterator) called with first iterator not"
         " referring to this list");
     _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == &__c,
         "list::splice(iterator, list, iterator, iterator) called with second iterator not"
         " referring to list argument");
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__l) == &__c,
+        "list::splice(iterator, list, iterator, iterator) called with third iterator not"
+        " referring to list argument");
     if (this == &__c)
     {
         for (const_iterator __i = __f; __i != __l; ++__i)
             _LIBCPP_ASSERT(__i != __p,
                            "list::splice(iterator, list, iterator, iterator)"
                            " called with the first iterator within the range"
                            " of the second and third iterators");
     }