SVN syntax and adding "contains" to existing match

[A. S. Budden]

Dear all (and Dmitry in particular),

Regarding the SVN syntax file, can I suggest a minor modification?
Would it be a good idea to add contains=@NoSpell onto the syn
\(match\|region\) lines so that spell checking can be done on the log
entry without also highlighting all the filenames that aren't real
words?

On a similar note, is it possible to have an entry in
~/.vim/after/syntax/*.vim that will take an existing match from the
core syntax files and add the contains=@NoSpell on without completely
redefining the whole syntax in ~/.vim/syntax/*.vim?

Cheers,

Al