Bug 607219 - dynamic role attribute change on body doesn't affect on document role. r=surkov,marcoz a=blocking2.0

accessible/src/base/nsDocAccessible.cpp

@@ -1024,8 +1024,21 @@ nsDocAccessible::AttributeChangedImpl(nsIContent* aContent, PRInt32 aNameSpaceID
     }
   }
 
-  if (aAttribute == nsAccessibilityAtoms::role ||
-      aAttribute == nsAccessibilityAtoms::href ||
+  if (aAttribute == nsAccessibilityAtoms::role) {
+    if (mContent == aContent) {
+      // It is common for js libraries to set the role of the body element after
+      // the doc has loaded. In this case we just update the role map entry. 
+      SetRoleMapEntry(nsAccUtils::GetRoleMapEntry(aContent));
+    }
+    else {
+      // Recreate the accessible when role is changed because we might require a
+      // different accessible class for the new role or the accessible may
+      // expose a different sets of interfaces (COM restriction).
+      RecreateAccessible(aContent);
+    }
+  }
+
+  if (aAttribute == nsAccessibilityAtoms::href ||
       aAttribute == nsAccessibilityAtoms::onclick) {
     // Not worth the expense to ensure which namespace these are in
     // It doesn't kill use to recreate the accessible even if the attribute was used

accessible/tests/mochitest/test_aria_roles.html

@@ -71,6 +71,12 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=529289
       testRole("scrollbar", ROLE_SCROLLBAR);
       testRole("dir", ROLE_LIST);
 
+      // test document role map update
+      var testDoc = getAccessible(document, [nsIAccessibleDocument]);
+      testRole(testDoc, ROLE_DOCUMENT);
+      document.body.setAttribute("role", "application");
+      testRole(testDoc, ROLE_APPLICATION);
+
       SimpleTest.finish();
     }
 
@@ -84,6 +90,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=529289
   <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=469688">Mozilla Bug 469688</a>
   <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=469688">Mozilla Bug 520188</a>
   <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=529289">Mozilla Bug 529289</a>
+  <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=529289">Mozilla Bug 607219</a>
   </a>
   <p id="display"></p>
   <div id="content" style="display: none"></div>