Fixed IAccessible::accNavigate for NAVDIR_NEXT and NAVDIR_PREVIOUS when start object was a simple c…

content/browser/accessibility/browser_accessibility_com_win.cc

 // Copyright (c) 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility_com_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include <algorithm>
@@ skipping 481 matching lines @@
   return AXPlatformNodeWin::accLocation(x_left, y_top, width, height, var_id);
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::accNavigate(LONG nav_dir,
                                                      VARIANT start,
                                                      VARIANT* end) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_ACC_NAVIGATE);
   if (!owner())
     return E_FAIL;
 
-  // Forward all directions but NAVDIR_ to the platform node implementation.
+  // Forward all logical directions (e.g. NAVDIR_NEXT) to the platform node

[dmazzoni, 2017/05/15 20:46:45]

The comment says NAVDIR_NEXT but the code below it
only includes UP, DOWN, LEFT and RIGHT.

+  // implementation.
   if (nav_dir != NAVDIR_DOWN && nav_dir != NAVDIR_UP &&
       nav_dir != NAVDIR_LEFT && nav_dir != NAVDIR_RIGHT) {
     return AXPlatformNodeWin::accNavigate(nav_dir, start, end);
   }
 
+  if (end) {
+    end->vt = VT_EMPTY;
+  } else {
+    return E_INVALIDARG;
+  }
+
   BrowserAccessibilityComWin* target = GetTargetFromChildID(start);
   if (!target)
     return E_INVALIDARG;
 
   BrowserAccessibility* result = nullptr;
+  // Only handle spatial directions for tables here.
   switch (nav_dir) {
     case NAVDIR_DOWN:
       result = target->owner()->GetTableCell(
           owner()->GetTableRow() + owner()->GetTableRowSpan(),
           owner()->GetTableColumn());
       break;
     case NAVDIR_UP:
       result = target->owner()->GetTableCell(owner()->GetTableRow() - 1,
                                              owner()->GetTableColumn());
       break;
     case NAVDIR_LEFT:
       result = target->owner()->GetTableCell(owner()->GetTableRow(),
                                              owner()->GetTableColumn() - 1);
       break;
     case NAVDIR_RIGHT:
       result = target->owner()->GetTableCell(
           owner()->GetTableRow(),
           owner()->GetTableColumn() + owner()->GetTableColumnSpan());
       break;
   }
 
-  if (!result) {
-    end->vt = VT_EMPTY;
+  if (!result)
     return S_FALSE;
-  }
 
   end->vt = VT_DISPATCH;
   end->pdispVal = ToBrowserAccessibilityComWin(result)->NewReference();
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityComWin::get_accChild(VARIANT var_child,
                                                       IDispatch** disp_child) {
   WIN_ACCESSIBILITY_API_HISTOGRAM(UMA_API_GET_ACC_CHILD);
   if (!owner())
@@ skipping 5174 matching lines @@
 
 BrowserAccessibilityComWin* ToBrowserAccessibilityComWin(
     BrowserAccessibility* obj) {
   if (!obj || !obj->IsNative())
     return nullptr;
   auto* result = static_cast<BrowserAccessibilityWin*>(obj)->GetCOM();
   return result;
 }
 
 }  // namespace content