Content-side DOM insertions made compatible with XML document.

Author: hackademix

src/content/PlaceHolder.js

@@ -2,6 +2,10 @@
 
  // debug = () => {}; // XPI_ONLY
 
+function createHTMLElement(name) {
+  return document.createElementNS("http://www.w3.org/1999/xhtml", name);
+}
+
 var _ = browser.i18n.getMessage;
 
 var canScript = true;

src/content/content.js

@@ -1,7 +1,7 @@
 function onScriptDisabled() {
   for (let noscript of document.querySelectorAll("noscript")) {
     // force show NOSCRIPT elements content
-    let replacement = document.createElement("no-script");
+    let replacement = createHTMLElement("no-script");
     replacement.innerHTML = noscript.innerHTML;
     noscript.parentNode.replaceChild(replacement, noscript);
     // emulate meta-refresh