fixed critical bug EXT-3559 Crash when deleting last Favorites entry

Cause:
An error of invalid array index.
Solution:
Additional check has been added.

--HG--
branch : product-engine

1 files changed, 6 insertions, 3 deletions

diff --git a/indra/newview/llfavoritesbar.cpp b/indra/newview/llfavoritesbar.cpp
index da0a9727a9..64af1225bf 100644
--- a/indra/newview/llfavoritesbar.cpp
+++ b/indra/newview/llfavoritesbar.cpp
@@ -657,7 +657,7 @@ void LLFavoritesBarCtrl::updateButtons()
 	int first_changed_item_index = 0;
 	int rightest_point = getRect().mRight - mChevronButton->getRect().getWidth();
 	//lets find first changed button
-	while (child_it != childs->end())
+	while (child_it != childs->end() && first_changed_item_index < mItems.count())
 	{
 		LLFavoriteLandmarkButton* button = dynamic_cast<LLFavoriteLandmarkButton*> (*child_it);
 		if (button)
@@ -675,9 +675,8 @@ void LLFavoritesBarCtrl::updateButtons()
 	}
 	// now first_changed_item_index should contains a number of button that need to change
 
-	if (first_changed_item_index < mItems.count())
+	if (first_changed_item_index <= mItems.count())
 	{
-		mUpdateDropDownItems = true;
 		// Rebuild the buttons only
 		// child_list_t is a linked list, so safe to erase from the middle if we pre-incrament the iterator
 
@@ -722,6 +721,10 @@ void LLFavoritesBarCtrl::updateButtons()
 		// Chevron button
 		if (mFirstDropDownItem < mItems.count())
 		{
+			// if updateButton had been called it means:
+			//or there are some new favorites, or width had been changed
+			// so if we need to display chevron button,  we must update dropdown items too. 
+			mUpdateDropDownItems = true;
 			S32 buttonHGap = 2; // default value
 			buttonXMLNode->getAttributeS32("left", buttonHGap);
 			LLRect rect;