Bug 1801879: Don't cross document boundaries in nsAccUtils::GetSelectableContainer. r=eeejay,geckoview-reviewers,owlish

Trying to access a local OuterDocAccessible from the Android UI thread was causing a crash.
We shouldn't be crossing document boundaries anyway.

Differential Revision: https://phabricator.services.mozilla.com/D163067

accessible/base/nsAccUtils.cpp

@@ -194,10 +194,13 @@ Accessible* nsAccUtils::GetSelectableContainer(const Accessible* aAccessible,
   if (!aAccessible) return nullptr;
 
   if (!(aState & states::SELECTABLE)) return nullptr;
+  MOZ_ASSERT(!aAccessible->IsDoc());
 
   const Accessible* parent = aAccessible;
   while ((parent = parent->Parent()) && !parent->IsSelect()) {
-    if (parent->Role() == roles::PANE) return nullptr;
+    if (parent->IsDoc() || parent->Role() == roles::PANE) {
+      return nullptr;
+    }
   }
   return const_cast<Accessible*>(parent);
 }

mobile/android/geckoview/src/androidTest/assets/www/accessibility/test-selectable.html

@@ -8,5 +8,6 @@
           this.getAttribute('aria-selected') == 'true' ? 'false' : 'true')">1</li>
       <li role="option" aria-selected="false">2</li>
   </ul>
+  <li id="outsideSelectable" role="option" tabindex="0">outside selectable</li>
 </body>
 </html>

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/AccessibilityTest.kt

@@ -1056,6 +1056,18 @@ class AccessibilityTest : BaseSessionTest() {
 
         provider.performAction(nodeId, AccessibilityNodeInfo.ACTION_SELECT, null)
         waitUntilSelect(false)
+
+        // Ensure that querying an option outside of a selectable container
+        // doesn't crash (bug 1801879).
+        mainSession.evaluateJS("document.getElementById('outsideSelectable').focus()")
+        sessionRule.waitUntilCalled(object : EventDelegate {
+            @AssertCalled(count = 1)
+            override fun onFocused(event: AccessibilityEvent) {
+                nodeId = getSourceId(event)
+                val node = createNodeInfo(nodeId)
+                assertThat("Focused outsideSelectable", node.text.toString(), equalTo("outside selectable"))
+            }
+        })
     }
 
     @Test fun testMutation() {