merging rlfletchers branch with a safer _.template when the template delimiter includes RegExp characters.

underscore.js

@@ -30,6 +30,9 @@
   // Export the Underscore object for CommonJS.
   if (typeof exports !== 'undefined') exports._ = _;
 
+  // Quick regexp-escaping function, because JS doesn't have RegExp.escape().
+  var escapeRegExp = function(s) { return s.replace(/([.*+?^${}()|[\]\/\\])/g, '\\$1'); };
+
   // Create quick reference variables for speed access to core prototypes.
   var slice                 = Array.prototype.slice,
       unshift               = Array.prototype.unshift,
@@ -576,7 +579,7 @@
       'var p=[],print=function(){p.push.apply(p,arguments);};' +
       'with(obj){p.push(\'' +
       str.replace(/[\r\t\n]/g, " ")
-         .replace(new RegExp("'(?=[^"+c.end[0]+"]*\\"+c.end.split('').join("\\")+")","g"),"\t")
+         .replace(new RegExp("'(?=[^"+c.end[0]+"]*"+escapeRegExp(c.end)+")","g"),"\t")
          .split("'").join("\\'")
          .split("\t").join("'")
          .replace(c.interpolate, "',$1,'")