I created a little hack [1], which is disabled at my site :)
Copy/paste from the link, because the group may break the lines
//{{{
(function(formatters) { //# set up alias
for (var i=0; i<formatters.length; i++) {
if (formatters[i].name == "characterFormat") {
merge( formatters[i],
{match: "''|//|__|\\^\\^|~~(?!\\s|$)|\\{\\{\\{"});
} // if
} // for
})(config.formatters); //# end of alias
//}}}
the original match looks like this:
match: "''|//|__|\\^\\^|~~|--(?!\\s|$)|\\{\\{\\{"});
Since "--" also means "mdash" all "--" will be rendered as mdashes
now.
have fun!
mario
[1]
http://hoster.peermore.com/recipes/TeamWork/tiddlers.wiki#RemoveStrikethroughHack