Add ability to escape comma in a scriptlet's list of arguments

An instance of `\,` will not be interpreted as an arguments
separator -- thus allowing the use of commas inside
argument values.

src/js/scriptlet-filtering.js

@@ -230,17 +230,26 @@
  toInject.set(rawToken, content);
  };
 
- // Fill template placeholders. Return falsy if:
- // - At least one argument contains anything else than /\w/ and `.`
-
+ // Fill-in scriptlet argument placeholders.
  const patchScriptlet = function(content, args) {
+ let s = args;
+ let len = s.length;
+ let beg = 0, pos = 0;
  let i = 1;
- while ( args !== '' ) {
- let pos = args.indexOf(',');
- if ( pos === -1 ) { pos = args.length; }
- const arg = args.slice(0, pos).trim().replace(reEscapeScriptArg, '\\$&');
- content = content.replace(`{{${i}}}`, arg);
- args = args.slice(pos + 1).trim();
+ while ( beg < len ) {
+ pos = s.indexOf(',', pos);
+ // Escaped comma? If so, skip.
+ if ( pos > 0 && s.charCodeAt(pos - 1) === 0x5C /* '\\' */ ) {
+ s = s.slice(0, pos - 1) + s.slice(pos);
+ len -= 1;
+ continue;
+ }
+ if ( pos === -1 ) { pos = len; }
+ content = content.replace(
+ `{{${i}}}`,
+ s.slice(beg, pos).trim().replace(reEscapeScriptArg, '\\$&')
+ );
+ beg = pos = pos + 1;
  i++;
  }
  return content;