Bug 1686839 - Apply MustPrune dynamically and not at creation time. r=morgan

Differential Revision: https://phabricator.services.mozilla.com/D101853

accessible/mac/AccessibleWrap.mm

@@ -71,17 +71,10 @@ mozAccessible* AccessibleWrap::GetNativeObject() {
     // We don't creat OSX accessibles for xul tooltips, defunct accessibles,
     // <br> (whitespace) elements, or pruned children.
     //
-    // We also don't create a native object if we're child of a "flat"
-    // accessible; for example, on OS X buttons shouldn't have any children,
-    // because that makes the OS confused.
-    //
     // To maintain a scripting environment where the XPCOM accessible hierarchy
     // look the same on all platforms, we still let the C++ objects be created
     // though.
-    Accessible* parent = Parent();
-    bool mustBePruned = parent && nsAccUtils::MustPrune(parent);
-    if (!IsXULTooltip() && !IsDefunct() && !mustBePruned &&
-        Role() != roles::WHITESPACE) {
+    if (!IsXULTooltip() && !IsDefunct() && Role() != roles::WHITESPACE) {
       mNativeObject = [[GetNativeType() alloc] initWithAccessible:this];
     }
   }

accessible/mac/Platform.mm

@@ -41,9 +41,7 @@ void PlatformInit() {}
 void PlatformShutdown() {}
 
 void ProxyCreated(ProxyAccessible* aProxy, uint32_t) {
-  ProxyAccessible* parent = aProxy->Parent();
-  if ((parent && nsAccUtils::MustPrune(parent)) ||
-      aProxy->Role() == roles::WHITESPACE) {
+  if (aProxy->Role() == roles::WHITESPACE) {
     // We don't create a native object if we're child of a "flat" accessible;
     // for example, on OS X buttons shouldn't have any children, because that
     // makes the OS confused. We also don't create accessibles for <br>

accessible/mac/mozAccessible.mm

@@ -96,7 +96,7 @@ using namespace mozilla::a11y;
 }
 
 - (BOOL)moxIgnoreChild:(mozAccessible*)child {
-  return NO;
+  return nsAccUtils::MustPrune(mGeckoAccessible);
 }
 
 - (id)childAt:(uint32_t)i {

accessible/tests/browser/mac/browser_hierarchy.js

@@ -27,3 +27,49 @@ addAccessibleTask(
     is(index, 1, "link is second child");
   }
 );
+
+/**
+ * Test textbox with more than one child
+ */
+addAccessibleTask(
+  `<div id="textbox" role="textbox">Hello <a href="#">strange</a> world</div>`,
+  (browser, accDoc) => {
+    let textbox = getNativeInterface(accDoc, "textbox");
+
+    is(
+      textbox.getAttributeValue("AXChildren").length,
+      3,
+      "textbox has 3 children"
+    );
+  }
+);
+
+/**
+ * Test textbox with one child
+ */
+addAccessibleTask(
+  `<div id="textbox" role="textbox">Hello </div>`,
+  async (browser, accDoc) => {
+    let textbox = getNativeInterface(accDoc, "textbox");
+
+    is(
+      textbox.getAttributeValue("AXChildren").length,
+      0,
+      "textbox with one child is pruned"
+    );
+
+    let reorder = waitForEvent(EVENT_REORDER, "textbox");
+    await SpecialPowers.spawn(browser, [], () => {
+      let link = content.document.createElement("a");
+      link.textContent = "World";
+      content.document.getElementById("textbox").appendChild(link);
+    });
+    await reorder;
+
+    is(
+      textbox.getAttributeValue("AXChildren").length,
+      2,
+      "textbox with two child is not pruned"
+    );
+  }
+);