Re: std::vector: Memory allocation in copy constructor for empty vector

[Paolo Carlini <pcarlini at suse dot de>]

Paolo Carlini wrote:

> I think we should do 2), seems doable. I'm looking into it.

To wit, I'm testing this kind of change. Seems safe. You should be able 
to apply it essentially unchanged to your 4.1 tree and give it a try.

Paolo.

/////////////
Index: stl_vector.h
===================================================================
--- stl_vector.h	(revision 127610)
+++ stl_vector.h	(working copy)
@@ -125,12 +125,12 @@
 
       _Tp*
       _M_allocate(size_t __n)
-      { return _M_impl.allocate(__n); }
+      { return __n != 0 ? _M_impl.allocate(__n) : 0; }
 
       void
       _M_deallocate(_Tp* __p, size_t __n)
       {
-	if (__p)
+	if (__p && __n)
 	  _M_impl.deallocate(__p, __n);
       }
     };