Encapsulation boundaries are of a form that contains at one point a
single number of arbitrary precision. The details are not important,
but as an example let me offer "Message separator (ID nnnn)" as one
possibility. Remember, the exact form can be different for different
systems generating these. The way you generate a specific separator
is with a single scan of the parts looking for any lines that look
like separators with this text and remembering the largest number that
appears. You then add one to that number and use it as the seperator
for the combined multipart message, this can't possibly exist in any
of the constituent parts, you have guaranteed correctness. A simple
implementation of this takes O(n) time, you can do better with
application of Boyer-Moore searching. The message separators are
pretty clear, even if you have an old UA that doesn't help you, in
most cases the "ID" is just a small integer which counts the amount of
nesting.
-Mike Patton
What happens when you find a sepatator format line of maximum allowed length
that consists of nothing but the highest possible allowed characters? (i.e. the
largest possible number)
+------------------------------------+--------------------------------------+
| James H. Thompson | jimmy_t(_at_)verifone(_dot_)com
(Internet) |
| VeriFone Inc. | uunet!verifone!jimmy_t (UUCP) |
| 100 Kahelu Avenue | 808-623-2911 (Phone) |
| Mililani, HI 96789 | |
+------------------------------------+--------------------------------------+