Bug 1328013 - Do not collect the flag of `allowJavascript` DocShell capabilities. r=mikedeboer

browser/components/sessionstore/DocShellCapabilities.jsm

@@ -19,6 +19,8 @@ this.DocShellCapabilities = Object.freeze({
   },
 });
 
+const CAPABILITIES_TO_IGNORE = new Set(["Javascript"]);
+
 /**
  * Internal functionality to save and restore the docShell.allow* properties.
  */
@@ -39,7 +41,8 @@ var DocShellCapabilitiesInternal = {
 
   collect(docShell) {
     let caps = this.allCapabilities(docShell);
-    return caps.filter(cap => !docShell["allow" + cap]);
+    return caps.filter(cap => !docShell["allow" + cap]
+                              && !CAPABILITIES_TO_IGNORE.has(cap));
   },
 
   restore(docShell, disallow) {

browser/components/sessionstore/test/browser_capabilities.js

@@ -24,6 +24,7 @@ add_task(async function docshell_capabilities() {
   // Flip a couple of allow* flags.
   docShell.allowImages = false;
   docShell.allowMetaRedirects = false;
+  docShell.allowJavascript = false;
 
   // Now reload the document to ensure that these capabilities
   // are taken into account.
@@ -58,11 +59,15 @@ add_task(async function docshell_capabilities() {
   ok(!docShell.allowImages, "images not allowed");
   ok(!docShell.allowMetaRedirects, "meta redirects not allowed");
 
+  // Check that docShell allowJavascript flag is not set.
+  ok(docShell.allowJavascript, "Javascript still allowed");
+
   // Check that we correctly restored features as disabled.
   state = JSON.parse(ss.getTabState(tab));
   disallow = new Set(state.disallow.split(","));
   ok(disallow.has("Images"), "images not allowed anymore");
   ok(disallow.has("MetaRedirects"), "meta redirects not allowed anymore");
+  ok(!disallow.has("Javascript"), "Javascript still allowed");
   is(disallow.size, 2, "two capabilities disallowed");
 
   // Clean up after ourselves.