diff --git a/mozilla/layout/forms/nsComboboxControlFrame.cpp b/mozilla/layout/forms/nsComboboxControlFrame.cpp
index ce76f428e55..9030326ce31 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/forms/nsComboboxControlFrame.cpp
@@ -1939,6 +1939,13 @@ nsComboboxControlFrame::SelectionChanged()
   return rv;
 }
 
+NS_IMETHODIMP
+nsComboboxControlFrame::GetIndexOfDisplayArea(PRInt32* aSelectedIndex)
+{
+  NS_ENSURE_ARG_POINTER(aSelectedIndex);
+  *aSelectedIndex = mSelectedIndex;
+  return NS_OK;
+}
 
 //----------------------------------------------------------------------
 // nsISelectControlFrame
diff --git a/mozilla/layout/forms/nsComboboxControlFrame.h b/mozilla/layout/forms/nsComboboxControlFrame.h
index 4584222a836..86607ea0544 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.h
+++ b/mozilla/layout/forms/nsComboboxControlFrame.h
@@ -166,6 +166,7 @@ public:
   NS_IMETHOD UpdateSelection(PRBool aDoDispatchEvent, PRBool aForceUpdate, PRInt32 aNewIndex);
   NS_IMETHOD AbsolutelyPositionDropDown();
   NS_IMETHOD GetAbsoluteRect(nsRect* aRect);
+  NS_IMETHOD GetIndexOfDisplayArea(PRInt32* aSelectedIndex);
 
   // nsISelectControlFrame
   NS_IMETHOD AddOption(nsIPresContext* aPresContext, PRInt32 index);
diff --git a/mozilla/layout/forms/nsIComboboxControlFrame.h b/mozilla/layout/forms/nsIComboboxControlFrame.h
index 38dd1cb024c..81ac099086e 100644
--- a/mozilla/layout/forms/nsIComboboxControlFrame.h
+++ b/mozilla/layout/forms/nsIComboboxControlFrame.h
@@ -115,6 +115,23 @@ public:
    */
   NS_IMETHOD SetFrameConstructor(nsCSSFrameConstructor *aConstructor) = 0;
 
+  /**
+   * This returns the index of the item that is currently being displayed
+   * in the display area. It may differ from what the currently Selected index
+   * is in in the dropdown.
+   *
+   * Detailed explanation: 
+   * When the dropdown is dropped down via a mouse click and the user moves the mouse 
+   * up and down without clicking, the currently selected item is being tracking inside 
+   * the dropdown, but the combobox is not being updated. When the user selects items
+   * with the arrow keys, the combobox is being updated. So when the user clicks outside
+   * the dropdown and it needs to roll up it has to decide whether to keep the current 
+   * selection or not. This method is used to get the current index in the combobox to
+   * compare it to the current index in the dropdown to see if the combox has been updated
+   * and that way it knows whether to "cancel" the the current selection residing in the 
+   * dropdown. Or whether to leave the selection alone.
+   */
+  NS_IMETHOD GetIndexOfDisplayArea(PRInt32* aSelectedIndex) = 0;
 };
 
 #endif
diff --git a/mozilla/layout/forms/nsListControlFrame.cpp b/mozilla/layout/forms/nsListControlFrame.cpp
index 2f0f6aea3ba..0f9b93694a5 100644
--- a/mozilla/layout/forms/nsListControlFrame.cpp
+++ b/mozilla/layout/forms/nsListControlFrame.cpp
@@ -2847,10 +2847,30 @@ nsListControlFrame::AboutToDropDown()
 NS_IMETHODIMP 
 nsListControlFrame::AboutToRollup()
 {
-  // XXX By uncommenting this line below the "act" of rolling up
-  // will reset the the contents of the combobox to it's original contents
-  // (i.e. the contents before it was dropped down
-  ResetSelectedItem();
+  // XXX To have clicking outside the combobox ALWAYS reset the contents to the
+  // state before it was dropped, remove the all the code in the "if" below and replace it
+  // with just the call to ResetSelectedItem()
+  //
+  //
+  // When the dropdown is dropped down via a mouse click and the user moves the mouse 
+  // up and down without clicking, the currently selected item is being tracking inside 
+  // the dropdown, but the combobox is not being updated. When the user selects items
+  // with the arrow keys, the combobox is being updated. So when the user clicks outside
+  // the dropdown and it needs to roll up it has to decide whether to keep the current 
+  // selection or not. The GetIndexOfDisplayArea method is used to get the current index 
+  // in the combobox to compare it to the current index in the dropdown to see if the combox 
+  // has been updated and that way it knows whether to "cancel" the the current selection 
+  // residing in the dropdown. Or whether to leave the selection alone.
+  if (IsInDropDownMode() == PR_TRUE) {
+    PRInt32 index;
+    mComboboxFrame->GetIndexOfDisplayArea(&index);
+    // if the indexes do NOT match then the selection in the combobox 
+    // was never updated, and therefore we should reset the the selection back to 
+    // whatever it was before it was dropped down.
+    if (index != mSelectedIndex) {
+      ResetSelectedItem();
+    }
+  }
   return NS_OK;
 }
 
diff --git a/mozilla/layout/html/forms/public/nsIComboboxControlFrame.h b/mozilla/layout/html/forms/public/nsIComboboxControlFrame.h
index 38dd1cb024c..81ac099086e 100644
--- a/mozilla/layout/html/forms/public/nsIComboboxControlFrame.h
+++ b/mozilla/layout/html/forms/public/nsIComboboxControlFrame.h
@@ -115,6 +115,23 @@ public:
    */
   NS_IMETHOD SetFrameConstructor(nsCSSFrameConstructor *aConstructor) = 0;
 
+  /**
+   * This returns the index of the item that is currently being displayed
+   * in the display area. It may differ from what the currently Selected index
+   * is in in the dropdown.
+   *
+   * Detailed explanation: 
+   * When the dropdown is dropped down via a mouse click and the user moves the mouse 
+   * up and down without clicking, the currently selected item is being tracking inside 
+   * the dropdown, but the combobox is not being updated. When the user selects items
+   * with the arrow keys, the combobox is being updated. So when the user clicks outside
+   * the dropdown and it needs to roll up it has to decide whether to keep the current 
+   * selection or not. This method is used to get the current index in the combobox to
+   * compare it to the current index in the dropdown to see if the combox has been updated
+   * and that way it knows whether to "cancel" the the current selection residing in the 
+   * dropdown. Or whether to leave the selection alone.
+   */
+  NS_IMETHOD GetIndexOfDisplayArea(PRInt32* aSelectedIndex) = 0;
 };
 
 #endif
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
index ce76f428e55..9030326ce31 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
@@ -1939,6 +1939,13 @@ nsComboboxControlFrame::SelectionChanged()
   return rv;
 }
 
+NS_IMETHODIMP
+nsComboboxControlFrame::GetIndexOfDisplayArea(PRInt32* aSelectedIndex)
+{
+  NS_ENSURE_ARG_POINTER(aSelectedIndex);
+  *aSelectedIndex = mSelectedIndex;
+  return NS_OK;
+}
 
 //----------------------------------------------------------------------
 // nsISelectControlFrame
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
index 4584222a836..86607ea0544 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
@@ -166,6 +166,7 @@ public:
   NS_IMETHOD UpdateSelection(PRBool aDoDispatchEvent, PRBool aForceUpdate, PRInt32 aNewIndex);
   NS_IMETHOD AbsolutelyPositionDropDown();
   NS_IMETHOD GetAbsoluteRect(nsRect* aRect);
+  NS_IMETHOD GetIndexOfDisplayArea(PRInt32* aSelectedIndex);
 
   // nsISelectControlFrame
   NS_IMETHOD AddOption(nsIPresContext* aPresContext, PRInt32 index);
diff --git a/mozilla/layout/html/forms/src/nsListControlFrame.cpp b/mozilla/layout/html/forms/src/nsListControlFrame.cpp
index 2f0f6aea3ba..0f9b93694a5 100644
--- a/mozilla/layout/html/forms/src/nsListControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsListControlFrame.cpp
@@ -2847,10 +2847,30 @@ nsListControlFrame::AboutToDropDown()
 NS_IMETHODIMP 
 nsListControlFrame::AboutToRollup()
 {
-  // XXX By uncommenting this line below the "act" of rolling up
-  // will reset the the contents of the combobox to it's original contents
-  // (i.e. the contents before it was dropped down
-  ResetSelectedItem();
+  // XXX To have clicking outside the combobox ALWAYS reset the contents to the
+  // state before it was dropped, remove the all the code in the "if" below and replace it
+  // with just the call to ResetSelectedItem()
+  //
+  //
+  // When the dropdown is dropped down via a mouse click and the user moves the mouse 
+  // up and down without clicking, the currently selected item is being tracking inside 
+  // the dropdown, but the combobox is not being updated. When the user selects items
+  // with the arrow keys, the combobox is being updated. So when the user clicks outside
+  // the dropdown and it needs to roll up it has to decide whether to keep the current 
+  // selection or not. The GetIndexOfDisplayArea method is used to get the current index 
+  // in the combobox to compare it to the current index in the dropdown to see if the combox 
+  // has been updated and that way it knows whether to "cancel" the the current selection 
+  // residing in the dropdown. Or whether to leave the selection alone.
+  if (IsInDropDownMode() == PR_TRUE) {
+    PRInt32 index;
+    mComboboxFrame->GetIndexOfDisplayArea(&index);
+    // if the indexes do NOT match then the selection in the combobox 
+    // was never updated, and therefore we should reset the the selection back to 
+    // whatever it was before it was dropped down.
+    if (index != mSelectedIndex) {
+      ResetSelectedItem();
+    }
+  }
   return NS_OK;
 }