I actually used %x intentionally because it is not a valid URL encoding. The error I was trying to correct for is when the content name includes a % character that is not a valid URL encoding. For example: "graph-of-75%-closure.png" or "report-50%x25%-success.xls". These types of names show up in the content sets of my customers, and trying to get a list of content items fails without my patch. Making the change to %20 here removes the purpose of the test.