[Bug libstdc++/60587] New: debug-mode -std=c++11 vector::insert(pos, begin, end) dereferences begin too eagerly

[sbergman at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60587

            Bug ID: 60587
           Summary: debug-mode -std=c++11 vector::insert(pos, begin, end)
                    dereferences begin too eagerly
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sbergman at redhat dot com

At least on recent trunk (r208675),

> $ cat test.cc
> #define _GLIBCXX_DEBUG
> #include <vector>
> int main() {
>     std::vector<int> a, b;
>     a.push_back(1);
>     a.insert(a.end(), b.begin(), b.end());
> }
> $ ~/gcc/trunk/inst/g++ -std=c++11 test.cc
> $ ./a.out
> ~/gcc/trunk/inst/include/c++/4.9.0/debug/safe_iterator.h:261:
>     error: attempt to dereference a past-the-end iterator.
>
> Objects involved in the operation:
> iterator "this" @ 0x0x7fff0d764060 {
> type = N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPiNSt9__cxx19986vectorIiSaIiEEEEENSt7__debug6vectorIiS6_EEEE (mutable iterator);
>   state = past-the-end;
>   references sequence with type `NSt7__debug6vectorIiSaIiEEE' @ 0x0x7fff0d764be0
> }

which

> Index: libstdc++-v3/include/debug/macros.h
> ===================================================================
> --- libstdc++-v3/include/debug/macros.h	(revision 208675)
> +++ libstdc++-v3/include/debug/macros.h	(working copy)
> @@ -106,7 +106,7 @@
>  #define __glibcxx_check_insert_range(_Position,_First,_Last)		\
>  __glibcxx_check_valid_range(_First,_Last);				\
>  __glibcxx_check_insert(_Position);					\
> -_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__foreign_iterator(_Position,_First),\
> +_GLIBCXX_DEBUG_VERIFY(_First==_Last||__gnu_debug::__foreign_iterator(_Position,_First),\
>  		      _M_message(__gnu_debug::__msg_insert_range_from_self)\
>  		      ._M_iterator(_First, #_First)			\
>  		      ._M_iterator(_Last, #_Last)			\

works around for me.