Bug 706784 - Firefox 8.0.1 Crash Report [@ nsLinkableAccessible::GetValue(nsAString_internal&) ], r=marcoz

accessible/src/msaa/nsAccessibleWrap.cpp

@@ -312,22 +312,25 @@ STDMETHODIMP nsAccessibleWrap::get_accValue(
 {
 __try {
   *pszValue = NULL;
+
   nsAccessible* xpAccessible = GetXPAccessibleFor(varChild);
-  if (xpAccessible) {
+  if (!xpAccessible || xpAccessible->IsDefunct())
+    return E_FAIL;
+
   nsAutoString value;
   if (NS_FAILED(xpAccessible->GetValue(value)))
     return E_FAIL;
 
-    // see bug 438784: Need to expose URL on doc's value attribute.
-    // For this, reverting part of fix for bug 425693 to make this MSAA method 
-    // behave IAccessible2-style.
+  // See bug 438784: need to expose URL on doc's value attribute. For this,
+  // reverting part of fix for bug 425693 to make this MSAA method behave
+  // IAccessible2-style.
   if (value.IsEmpty())
     return S_FALSE;
 
   *pszValue = ::SysAllocStringLen(value.get(), value.Length());
   if (!*pszValue)
     return E_OUTOFMEMORY;
-  }
+
 } __except(FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
   return S_OK;
 }