Fixes #151 ("Buffer overflow in monotonic_buffer_resource::do_allocate").

doc/container.qbk

@@ -1329,6 +1329,7 @@ use [*Boost.Container]? There are several reasons for that:
    * [@https://github.com/boostorg/container/issues/145    GitHub #145: ['"Allocations not handled correctly in some cases of vector move with unequal allocators"]].
    * [@https://github.com/boostorg/container/pull/146      GitHub #146: ['"Changes for Embarcadero C++ clang-based compilers, targeting Boost 1.74. Addition needed for Embarcardero clang-based compilers"]].
    * [@https://github.com/boostorg/container/pull/148      GitHub #148: ['"Fix static initialization issues in pmr global resources"]].
+   * [@https://github.com/boostorg/container/issues/151    GitHub #151: ['"Buffer overflow in monotonic_buffer_resource::do_allocate"]].
 
 [endsect]
 

src/monotonic_buffer_resource.cpp

@@ -141,6 +141,9 @@ void* monotonic_buffer_resource::do_allocate(std::size_t bytes, std::size_t alig
    //See if there is room in current buffer
    std::size_t aligner = 0u;
    if(this->remaining_storage(alignment, aligner) < bytes){
+      //The new buffer will be aligned to the strictest alignment so reset
+      //the aligner, which was needed for the old buffer.
+      aligner = 0u;
       //Update next_buffer_size to at least bytes
       this->increase_next_buffer_at_least_to(bytes);
       //Now allocate and update internal data