[PATCH][libcxx] Prevent '\b' from backing up into invalid memory (case 2)

[Howard Hinnant]

On Jul 10, 2013, at 2:31 PM, William Fisher <william.w.fisher at gmail.com> wrote:

> This patch fixes a less likely case where '\b' can back up into invalid memory, when driven by a regex_iterator (for case 1, see r185273 or http://llvm.org/bugs/show_bug.cgi?id=16240)
> 
> The attached test program also supplies a test for the case 1 fix in r185273.
> 
> Thanks,
> -Bill

Committed revision 186089.

Thanks Bill!

Howard