Always check if View::GetWidget() is NULL.

ui/views/accessibility/native_view_accessibility_win.cc

 // Copyright (c) 2012 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 "ui/views/accessibility/native_view_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <oleacc.h>
 
 #include <set>
@@ skipping 236 matching lines @@
   view_ = NULL;
   Release();
 }
 
 STDMETHODIMP NativeViewAccessibilityWin::accHitTest(
     LONG x_left, LONG y_top, VARIANT* child) {
   if (!child)
     return E_INVALIDARG;
 
   if (!view_)
     return E_FAIL;

[sky, 2013/11/04 21:06:36]

Should the check for widget be moved here?

[dmazzoni, 2013/11/04 21:12:16]

That seems reasonable. If there's no widget, it can't possibly be returning any
useful information.

I made a similar change throughout.

 
   // If this is a root view, our widget might have child widgets.
   // Search child widgets first, since they're on top in the z-order.
-  if (view_->GetWidget()->GetRootView() == view_) {
+  if (view_->GetWidget() && view_->GetWidget()->GetRootView() == view_) {
     std::vector<Widget*> child_widgets;
     PopulateChildWidgetVector(&child_widgets);
     for (size_t i = 0; i < child_widgets.size(); ++i) {
       Widget* child_widget = child_widgets[i];
       IAccessible* child_accessible =
           child_widget->GetRootView()->GetNativeViewAccessible();
       HRESULT result = child_accessible->accHitTest(x_left, y_top, child);
       if (result == S_OK)
         return result;
     }
@@ skipping 194 matching lines @@
 
   LONG child_id = V_I4(&var_child);
 
   if (child_id == CHILDID_SELF) {
     // Remain with the same dispatch.
     return S_OK;
   }
 
   // If this is a root view, our widget might have child widgets. Include
   std::vector<Widget*> child_widgets;
-  if (view_->GetWidget()->GetRootView() == view_)
+  if (view_->GetWidget() && view_->GetWidget()->GetRootView() == view_)
     PopulateChildWidgetVector(&child_widgets);
   int child_widget_count = static_cast<int>(child_widgets.size());
 
   View* child_view = NULL;
   if (child_id > 0) {
     // Positive child ids are a 1-based child index, used by clients
     // that want to enumerate all immediate children.
     int child_id_as_index = child_id - 1;
     if (child_id_as_index < view_->child_count()) {
       child_view = view_->child_at(child_id_as_index);
@@ skipping 46 matching lines @@
   if (!child_count || !view_)
     return E_INVALIDARG;
 
   if (!view_)
     return E_FAIL;
 
   *child_count = view_->child_count();
 
   // If this is a root view, our widget might have child widgets. Include
   // them, too.
-  if (view_->GetWidget()->GetRootView() == view_) {
+  if (view_->GetWidget() && view_->GetWidget()->GetRootView() == view_) {
     std::vector<Widget*> child_widgets;
     PopulateChildWidgetVector(&child_widgets);
     *child_count += child_widgets.size();
   }
 
   return S_OK;
 }
 
 STDMETHODIMP NativeViewAccessibilityWin::get_accDefaultAction(
     VARIANT var_id, BSTR* def_action) {
@@ skipping 831 matching lines @@
   HandleSpecialTextOffset(text, &start_offset);
   ui::TextBoundaryType boundary = IA2TextBoundaryToTextBoundary(ia2_boundary);
   std::vector<int32> line_breaks;
   return ui::FindAccessibleTextBoundary(
       text, line_breaks, boundary, start_offset, direction);
 }
 
 void NativeViewAccessibilityWin::PopulateChildWidgetVector(
     std::vector<Widget*>* result_child_widgets) {
   const Widget* widget = view()->GetWidget();
+  if (!widget)
+    return;
+
   std::set<Widget*> child_widgets;
   Widget::GetAllChildWidgets(widget->GetNativeView(), &child_widgets);
   Widget::GetAllOwnedWidgets(widget->GetNativeView(), &child_widgets);
   for (std::set<Widget*>::const_iterator iter = child_widgets.begin();
            iter != child_widgets.end(); ++iter) {
     Widget* child_widget = *iter;
     if (child_widget == widget)
       continue;
 
     if (!child_widget->IsVisible())
       continue;
 
     if (widget->GetNativeWindowProperty(kWidgetNativeViewHostKey))
       continue;
 
     result_child_widgets->push_back(child_widget);
   }
 }
 
 }  // namespace views