$ being mangled even when reserved

[BradleyStaples]

I'm using a jQuery plugin for tagging (https://github.com/daniel-zahariev/jquery-textntags/blob/master/jquery-textntags.js) and uglify is still overriding the $ as a variable even when told not to with the -r flag. Noticed from a build script, but manually running the following command duplicates the issue for me.

uglifyjs jquery-textntags.js -c "warnings=false" -d IS_SERVER=false -m -r '$,require,exports'

Specifically, the editorSelectionLength variable is the one this is happening to (currently line 87). I noticed the issue of this same variable being reassigned within a switch statement around line 286 as well.

[colorhook]

+1

(function($){
     var a = $("a");a.a;
     var aa = $("a");aa.a;
 })($, $$);

minified to:

!function($){var a=$("a");a.a;var $=$("a");$.$}($,$$);

[colorhook]

I have found a hack method:

Before mangling the source code, find all the custom reserved keywork defined by except option, and set the mangled_name to itself.

var except = ['$', 'exports', 'define', 'require'];

var toplevel = UglifyJS.parse(filecontent, {filename: "?", toplevel: null});

//mangle
var $next_mangled = UglifyJS.AST_Scope.prototype.next_mangled;
UglifyJS.AST_Scope.prototype.next_mangled = function(options){
   var m = $next_mangled.call(this, options);
   while(except.indexOf(m) != -1){
      m = $next_mangled.call(this, options);
   }
   return m;
}

toplevel.figure_out_scope();
toplevel.compute_char_frequency();
toplevel.mangle_names({except: except});

Also created a pull request to fix it:

AST_Scope.DEFMETHOD("next_mangled", function(options){
    var ext = this.enclosed;
    out: while (true) {
        var m = base54(++this.cname);
        if (!is_identifier(m)) continue; // skip over "do"
        // we must ensure that the mangled name does not shadow a name
        // from some parent scope that is referenced in this or in
        // inner scopes.
        if(options.except.indexOf(m) !== -1){
            continue;
        }
        for (var i = ext.length; --i >= 0;) {
            var sym = ext[i];
            var name = sym.mangled_name || (sym.unmangleable(options) && sym.name);
            if (m == name) continue out;
        }
        console.log(m);
        return m;
    }
});

[mishoo]

Closed with PR #371