Added more checks to ACE_Double_Linked_List::remove_element to prevent

double removal of elements.

2 files changed, 7 insertions, 3 deletions

diff --git a/ace/Containers.cpp b/ace/Containers.cpp
index 0728099a65e..1a78ba29624 100644
--- a/ace/Containers.cpp
+++ b/ace/Containers.cpp
@@ -905,11 +905,13 @@ ACE_Double_Linked_List<T>::remove_element (T *item)
   // Notice that you have to ensure that item is an element of this
   // list.  We can't do much checking here.
 
-  if (item == this->head_ || this->size () == 0)      // Can't remove head
+  if (item == this->head_ || item->next_ == 0
+      || item->prev_ == 0 || this->size () == 0)      // Can't remove head
     return -1;
 
   item->prev_->next_ = item->next_;
   item->next_->prev_ = item->prev_;
+  item->next_ = item->prev_ = 0; // reset pointers to prevent double removal.
   this->size_--;
   return 0;
 }
diff --git a/ace/Containers.h b/ace/Containers.h
index 5a042a65488..af4b37d5c76 100644
--- a/ace/Containers.h
+++ b/ace/Containers.h
@@ -650,8 +650,10 @@ protected:
 
   int remove_element (T *item);
   // Remove an <item> from the list.  Return 0 if succeed, -1 otherwise.
-  // Notice that this function only checks if item is <head_>.  Users
-  // must ensure the item is in the list.
+  // Notice that this function checks if item is <head_> and either its
+  // <next_> or <prev_> is NULL.  The function resets item's <next_> and
+  // <prev_> to 0 to prevent clobbering the double-linked list if a user
+  // tries to remove the same node again.
   
   T *head_;
   // Head of the circular double-linked list.