deque fails to meet 23.2.1.3.4-5 causing invalid iterators and extra assignments

[Paolo Carlini]

Steve LoBasso wrote:
> Will this trickle down as a patch fix into older versions of libstdc++, or is deque::erase() forever broken in those older versions?
>   
Well, we have to stay to the GCC longtime rules, in general: this 
problem, while very annoying isn't a regression, therefore in principle 
the fix should go in mainline only, appearing in 4.3.0. Everything 
considered, I think we can have it 4.2.0 too, after a few days of 
testing in mainline. Please let us know ASAP in case you encounter any 
problem while stressing the patched deque::erase together with your code...

Thanks,
Paolo.