[gcc r14-9087] libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_wrap behavior

[gcc r14-9087] libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_wrap behavior

[Francois Dumont]

https://gcc.gnu.org/g:ca5f509903315a56b2f306f8644544861a6525cb

commit r14-9087-gca5f509903315a56b2f306f8644544861a6525cb
Author: François Dumont <fdumont@gcc.gnu.org>
Date:   Tue Feb 20 19:24:47 2024 +0100

    libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_wrap behavior
    
    In _GLIBCXX_DEBUG mode the std::__niter_base can remove 2 layers, the
    __gnu_debug::_Safe_iterator<> and the __gnu_cxx::__normal_iterator<>.
    When std::__niter_wrap is called to build a __gnu_debug::_Safe_iterator<>
    from a __gnu_cxx::__normal_iterator<> we then have a consistency issue
    as the difference between the 2 iterators will done on a __normal_iterator
    on one side and a C pointer on the other. To avoid this problem call
    std::__niter_base on both input iterators.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/stl_algobase.h (std::__niter_wrap): Add a call to
            std::__niter_base on res iterator.

Diff:
---
 libstdc++-v3/include/bits/stl_algobase.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index 0f73da131729..d534e02871f6 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -344,7 +344,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     _GLIBCXX20_CONSTEXPR
     inline _From
     __niter_wrap(_From __from, _To __res)
-    { return __from + (__res - std::__niter_base(__from)); }
+    { return __from + (std::__niter_base(__res) - std::__niter_base(__from)); }
 
   // No need to wrap, iterator already has the right type.
   template<typename _Iterator>