[Voted into WP at March, 2010 meeting.]

Proposed resolution (October, 2009):

Change 5.13.9 [lex.ext] paragraph 5 as follows:

If L is a user-defined-string-literal, let str be the literal without its ud-suffix and let len be the number of characters (or code points) code units in str (i.e., its length excluding the terminating null character)...

5.13.9 [lex.ext] paragraph 5 says,

If L is a user-defined-string-literal, let str be the literal without its ud-suffix and let len be the number of characters (or code points) in str (i.e., its length excluding the terminating null character).

The length of a null-terminated string is defined in 16.3.3.3.4.2 [byte.strings] as the number of bytes preceding the terminator, but a single code point in a UTF-8 string can require more than one byte, so this sentence is inconsistent and needs to be revised to make clear which definition is in view.