Add input validation for html param in setHTML()

src/node/db/API.js

@@ -382,8 +382,23 @@ exports.getHTML = function(padID, rev, callback)
   });
 }
 
+/**
+setHTML(padID, html) sets the text of a pad based on HTML
+
+Example returns:
+
+{code: 0, message:"ok", data: null}
+{code: 1, message:"padID does not exist", data: null}
+*/
 exports.setHTML = function(padID, html, callback)
 {
+  //html is required
+  if(typeof html != "string")
+  {
+    callback(new customError("html is no string","apierror"));
+    return;
+  }
+
   //get the pad
   getPadSafe(padID, true, function(err, pad)
   {