id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
5086	Fix for possible assertion failure in MSVC isctype.c	Kazutoshi Satoda <k_satoda@…>	jsiek	"Ticket #4791 about warning C6328 was closed as fixed. But in fact, the
fix (r66855) only silenced the warning, not addressing the real problem
indicated by the warning.

The problem is explained [http://msdn.microsoft.com/en-us/library/ms245348.aspx here].
In short: (for character classification functions in <cctype>)
> the valid range of values for its input argument is:
>   0 <= c <= 255, plus the special value EOF.
Otherwise, the behavior is undefined. Thus, passing an user provided
value of char (may be signed) can cause UB. The existing comment just
above struct traits_extension addresses the same issue.

Nothing was changed by the static_cast<int> introduced by the fix. It
just expressed what the compiler implicitly does (integral promotion).

Here is the patch to fix the real problem, including a test about the
problem."	Patches	new	To Be Determined	tokenizer	Boost Development Trunk	Problem