diff --git a/indra/llui/llaccordionctrl.cpp b/indra/llui/llaccordionctrl.cpp
index dca43c578444f200db9fe7f4a7c8c49d30f63709..5d1d57cbb28e26f9c5f0118cf63203594cdaf8fc 100644
--- a/indra/llui/llaccordionctrl.cpp
+++ b/indra/llui/llaccordionctrl.cpp
@@ -329,7 +329,7 @@ void LLAccordionCtrl::addCollapsibleCtrl(LLView* view)
 	LLAccordionCtrlTab* accordion_tab = dynamic_cast<LLAccordionCtrlTab*>(view);
 	if(!accordion_tab)
 		return;
-	if(std::find(getChildList()->begin(),getChildList()->end(),accordion_tab) == getChildList()->end())
+	if(std::find(beginChild(), endChild(), accordion_tab) == endChild())
 		addChild(accordion_tab);
 	mAccordionTabs.push_back(accordion_tab);
 
@@ -343,7 +343,7 @@ void LLAccordionCtrl::removeCollapsibleCtrl(LLView* view)
 	if(!accordion_tab)
 		return;
 
-	if(std::find(getChildList()->begin(),getChildList()->end(),accordion_tab) != getChildList()->end())
+	if(std::find(beginChild(), endChild(), accordion_tab) != endChild())
 		removeChild(accordion_tab);
 
 	for (std::vector<LLAccordionCtrlTab*>::iterator iter = mAccordionTabs.begin();
diff --git a/indra/llui/llaccordionctrltab.cpp b/indra/llui/llaccordionctrltab.cpp
index d38923664235037953a8a0d4cfcefdf9388f0a6e..3c706ce90edbbdebefa60a470e3173b5a61bc7c9 100644
--- a/indra/llui/llaccordionctrltab.cpp
+++ b/indra/llui/llaccordionctrltab.cpp
@@ -554,7 +554,8 @@ S32	LLAccordionCtrlTab::notifyParent(const LLSD& info)
 			}
 			
 			//LLAccordionCtrl should rearrange accodion tab if one of accordion change its size
-			getParent()->notifyParent(info);
+			if (getParent()) // A parent may not be set if tabs are added dynamically.
+				getParent()->notifyParent(info);
 			return 1;
 		}
 		else if(str_action == "select_prev") 
diff --git a/indra/newview/llinventoryitemslist.cpp b/indra/newview/llinventoryitemslist.cpp
index 9f54b86607e99c71236868d584ad41cb8c5f48c3..dca130c672996f010685abca88455f4e60f3bafd 100644
--- a/indra/newview/llinventoryitemslist.cpp
+++ b/indra/newview/llinventoryitemslist.cpp
@@ -2,6 +2,10 @@
  * @file llinventoryitemslist.cpp
  * @brief A list of inventory items represented by LLFlatListView.
  *
+ * Class LLInventoryItemsList implements a flat list of inventory items.
+ * Class LLPanelInventoryListItem displays inventory item as an element
+ * of LLInventoryItemsList.
+ *
  * $LicenseInfo:firstyear=2010&license=viewergpl$
  *
  * Copyright (c) 2010, Linden Research, Inc.
@@ -39,33 +43,31 @@
 #include "lliconctrl.h"
 
 #include "llinventoryfunctions.h"
+#include "llinventorymodel.h"
 #include "lltextutil.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 
-LLPanelInventoryItem::LLPanelInventoryItem(LLAssetType::EType asset_type,
-										   LLInventoryType::EType inventory_type,
-										   U32 wearable_type,
-										   const std::string &item_name,
-										   const std::string &hl)
-:	 LLPanel()
-	,mItemName(item_name)
-	,mHighlightedText(hl)
-	,mIcon(NULL)
-	,mTitle(NULL)
+// static
+LLPanelInventoryListItem* LLPanelInventoryListItem::createItemPanel(const LLViewerInventoryItem* item)
 {
-	mItemIcon = get_item_icon(asset_type, inventory_type, wearable_type, FALSE);
-
-	LLUICtrlFactory::getInstance()->buildPanel(this, "panel_inventory_item.xml");
+	if (item)
+	{
+		return new LLPanelInventoryListItem(item);
+	}
+	else
+	{
+		return NULL;
+	}
 }
 
-LLPanelInventoryItem::~LLPanelInventoryItem()
+LLPanelInventoryListItem::~LLPanelInventoryListItem()
 {}
 
 //virtual
-BOOL LLPanelInventoryItem::postBuild()
+BOOL LLPanelInventoryListItem::postBuild()
 {
 	mIcon = getChild<LLIconCtrl>("item_icon");
 	mTitle = getChild<LLTextBox>("item_name");
@@ -76,14 +78,14 @@ BOOL LLPanelInventoryItem::postBuild()
 }
 
 //virtual
-void LLPanelInventoryItem::setValue(const LLSD& value)
+void LLPanelInventoryListItem::setValue(const LLSD& value)
 {
 	if (!value.isMap()) return;
 	if (!value.has("selected")) return;
 	childSetVisible("selected_icon", value["selected"]);
 }
 
-void LLPanelInventoryItem::updateItem()
+void LLPanelInventoryListItem::updateItem()
 {
 	if (mItemIcon.notNull())
 		mIcon->setImage(mItemIcon);
@@ -95,28 +97,47 @@ void LLPanelInventoryItem::updateItem()
 		mHighlightedText);
 }
 
-void LLPanelInventoryItem::onMouseEnter(S32 x, S32 y, MASK mask)
+void LLPanelInventoryListItem::onMouseEnter(S32 x, S32 y, MASK mask)
 {
 	childSetVisible("hovered_icon", true);
 
 	LLPanel::onMouseEnter(x, y, mask);
 }
 
-void LLPanelInventoryItem::onMouseLeave(S32 x, S32 y, MASK mask)
+void LLPanelInventoryListItem::onMouseLeave(S32 x, S32 y, MASK mask)
 {
 	childSetVisible("hovered_icon", false);
 
 	LLPanel::onMouseLeave(x, y, mask);
 }
 
+LLPanelInventoryListItem::LLPanelInventoryListItem(const LLViewerInventoryItem* item)
+:	 LLPanel()
+	,mIcon(NULL)
+	,mTitle(NULL)
+{
+	mItemName = item->getName();
+	mItemIcon = get_item_icon(item->getType(), item->getInventoryType(), item->getFlags(), FALSE);
+
+	LLUICtrlFactory::getInstance()->buildPanel(this, "panel_inventory_item.xml");
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 
-LLInventoryItemsList::LLInventoryItemsList(const LLFlatListView::Params& p)
+LLInventoryItemsList::Params::Params()
+{}
+
+LLInventoryItemsList::LLInventoryItemsList(const LLInventoryItemsList::Params& p)
 :	LLFlatListView(p)
 ,	mNeedsRefresh(false)
-{}
+{
+	// TODO: mCommitOnSelectionChange is set to "false" in LLFlatListView
+	// but reset to true in all derived classes. This settings might need to
+	// be added to LLFlatListView::Params() and/or set to "true" by default.
+	setCommitOnSelectionChange(true);
+}
 
 // virtual
 LLInventoryItemsList::~LLInventoryItemsList()
@@ -196,10 +217,15 @@ void LLInventoryItemsList::computeDifference(
 
 void LLInventoryItemsList::addNewItem(LLViewerInventoryItem* item)
 {
-	llassert(item);
+	if (!item)
+	{
+		llwarns << "No inventory item. Couldn't create flat list item." << llendl;
+		llassert(!"No inventory item. Couldn't create flat list item.");
+	}
 
-	LLPanelInventoryItem *list_item = new LLPanelInventoryItem(item->getType(),
-		item->getInventoryType(), item->getFlags(), item->getName(), LLStringUtil::null);
+	LLPanelInventoryListItem *list_item = LLPanelInventoryListItem::createItemPanel(item);
+	if (!list_item)
+		return;
 
 	if (!addItem(list_item, item->getUUID()))
 	{
diff --git a/indra/newview/llinventoryitemslist.h b/indra/newview/llinventoryitemslist.h
index 0ca4146867f2b79525f07856c3f5329a2bbf4b47..b496f4b9e94c74a24e16997154fa31bd010f4616 100644
--- a/indra/newview/llinventoryitemslist.h
+++ b/indra/newview/llinventoryitemslist.h
@@ -2,6 +2,10 @@
  * @file llinventoryitemslist.h
  * @brief A list of inventory items represented by LLFlatListView.
  *
+ * Class LLInventoryItemsList implements a flat list of inventory items.
+ * Class LLPanelInventoryListItem displays inventory item as an element
+ * of LLInventoryItemsList.
+ *
  * $LicenseInfo:firstyear=2010&license=viewergpl$
  *
  * Copyright (c) 2010, Linden Research, Inc.
@@ -32,28 +36,23 @@
 #ifndef LL_LLINVENTORYITEMSLIST_H
 #define LL_LLINVENTORYITEMSLIST_H
 
-#include "llpanel.h"
-
-#include "llassettype.h"
+#include "lldarray.h"
 
-#include "llinventorytype.h"
+#include "llpanel.h"
 
 // newview
 #include "llflatlistview.h"
-#include "llinventorymodel.h"
 
 class LLIconCtrl;
 class LLTextBox;
+class LLViewerInventoryItem;
 
-class LLPanelInventoryItem : public LLPanel
+class LLPanelInventoryListItem : public LLPanel
 {
 public:
-	LLPanelInventoryItem(LLAssetType::EType asset_type,
-						 LLInventoryType::EType inventory_type,
-						 U32 wearable_type,
-						 const std::string &item_name,
-						 const std::string &hl);
-	virtual ~LLPanelInventoryItem();
+	static LLPanelInventoryListItem* createItemPanel(const LLViewerInventoryItem* item);
+
+	virtual ~LLPanelInventoryListItem();
 
 	/*virtual*/ BOOL postBuild();
 	/*virtual*/ void setValue(const LLSD& value);
@@ -63,6 +62,9 @@ class LLPanelInventoryItem : public LLPanel
 	void onMouseEnter(S32 x, S32 y, MASK mask);
 	void onMouseLeave(S32 x, S32 y, MASK mask);
 
+protected:
+	LLPanelInventoryListItem(const LLViewerInventoryItem* item);
+
 private:
 	LLIconCtrl*		mIcon;
 	LLTextBox*		mTitle;
@@ -72,13 +74,17 @@ class LLPanelInventoryItem : public LLPanel
 	std::string		mHighlightedText;
 };
 
-
 class LLInventoryItemsList : public LLFlatListView
 {
 public:
+	struct Params : public LLInitParam::Block<Params, LLFlatListView::Params>
+	{
+		Params();
+	};
+
 	virtual ~LLInventoryItemsList();
 
-	void refreshList(const LLInventoryModel::item_array_t item_array);
+	void refreshList(const LLDynamicArray<LLPointer<LLViewerInventoryItem> > item_array);
 
 	/**
 	 * Let list know items need to be refreshed in next draw()
@@ -91,7 +97,7 @@ class LLInventoryItemsList : public LLFlatListView
 
 protected:
 	friend class LLUICtrlFactory;
-	LLInventoryItemsList(const LLFlatListView::Params& p);
+	LLInventoryItemsList(const LLInventoryItemsList::Params& p);
 
 	uuid_vec_t& getIDs() { return mIDs; }
 
diff --git a/indra/newview/llinventoryobserver.cpp b/indra/newview/llinventoryobserver.cpp
index 03006243f9f8fde72c882095dc78e1f07e652ed5..214b5d317a530f6773fe545693ed972d136d7b91 100644
--- a/indra/newview/llinventoryobserver.cpp
+++ b/indra/newview/llinventoryobserver.cpp
@@ -658,11 +658,13 @@ void LLInventoryCategoriesObserver::changed(U32 mask)
 
 	for (category_map_t::iterator iter = mCategoryMap.begin();
 		 iter != mCategoryMap.end();
-		 iter++)
+		 ++iter)
 	{
-		// Inventory category version is used to find out if some changes
-		// to a category have been made.
-		S32 version = gInventory.getCategory((*iter).first)->getVersion();
+		LLViewerInventoryCategory* category = gInventory.getCategory((*iter).first);
+		if (!category)
+			continue;
+
+		S32 version = category->getVersion();
 		if (version != (*iter).second.mVersion)
 		{
 			// Update category version in map.
@@ -674,11 +676,27 @@ void LLInventoryCategoriesObserver::changed(U32 mask)
 
 void LLInventoryCategoriesObserver::addCategory(const LLUUID& cat_id, callback_t cb)
 {
-	S32 version = gInventory.getCategory(cat_id)->getVersion();
+	S32 version;
+	LLViewerInventoryCategory* category = gInventory.getCategory(cat_id);
+	if (category)
+	{
+		// Inventory category version is used to find out if some changes
+		// to a category have been made.
+		version = category->getVersion();
+	}
+	else
+	{
+		// If category could not be retrieved it might mean that
+		// inventory is unusable at the moment so the category is
+		// stored with VERSION_UNKNOWN and it may be updated later.
+		version = LLViewerInventoryCategory::VERSION_UNKNOWN;
+	}
+
+	version = category->getVersion();
 	mCategoryMap.insert(category_map_value_t(cat_id, LLCategoryData(cb, version)));
 }
 
 void LLInventoryCategoriesObserver::removeCategory(const LLUUID& cat_id)
 {
-	mCategoryMap.erase(mCategoryMap.find(cat_id));
+	mCategoryMap.erase(cat_id);
 }
diff --git a/indra/newview/lloutfitslist.cpp b/indra/newview/lloutfitslist.cpp
index cce4f940288100d3d0ba8c1d9a17935afe43b04f..1c627d452fb6b4e26fa5278a9c20606f942d6004 100644
--- a/indra/newview/lloutfitslist.cpp
+++ b/indra/newview/lloutfitslist.cpp
@@ -33,6 +33,9 @@
 
 #include "lloutfitslist.h"
 
+// llcommon
+#include "llcommonutils.h"
+
 #include "llaccordionctrl.h"
 #include "llaccordionctrltab.h"
 #include "llinventoryfunctions.h"
@@ -45,7 +48,12 @@ LLOutfitsList::LLOutfitsList()
 	:	LLPanel()
 	,	mAccordion(NULL)
 	,	mListCommands(NULL)
-{}
+{
+	mCategoriesObserver = new LLInventoryCategoriesObserver();
+	gInventory.addObserver(mCategoriesObserver);
+
+	gInventory.addObserver(this);
+}
 
 LLOutfitsList::~LLOutfitsList()
 {
@@ -65,11 +73,6 @@ BOOL LLOutfitsList::postBuild()
 {
 	mAccordion = getChild<LLAccordionCtrl>("outfits_accordion");
 
-	mCategoriesObserver = new LLInventoryCategoriesObserver();
-	gInventory.addObserver(mCategoriesObserver);
-
-	gInventory.addObserver(this);
-
 	return TRUE;
 }
 
@@ -79,15 +82,15 @@ void LLOutfitsList::changed(U32 mask)
 	if (!gInventory.isInventoryUsable())
 		return;
 
-	// Start observing changes in "My Outfits" category.
 	const LLUUID outfits = gInventory.findCategoryUUIDForType(LLFolderType::FT_MY_OUTFITS);
-	mCategoriesObserver->addCategory(outfits,
-			boost::bind(&LLOutfitsList::refreshList, this, outfits));
-
 	LLViewerInventoryCategory* category = gInventory.getCategory(outfits);
 	if (!category)
 		return;
 
+	// Start observing changes in "My Outfits" category.
+	mCategoriesObserver->addCategory(outfits,
+			boost::bind(&LLOutfitsList::refreshList, this, outfits));
+
 	// Fetch "My Outfits" contents and refresh the list to display
 	// initially fetched items. If not all items are fetched now
 	// the observer will refresh the list as soon as the new items
@@ -121,7 +124,7 @@ void LLOutfitsList::refreshList(const LLUUID& category_id)
 	// Creating a vector of newly collected sub-categories UUIDs.
 	for (LLInventoryModel::cat_array_t::const_iterator iter = cat_array.begin();
 		 iter != cat_array.end();
-		 iter++)
+		 ++iter)
 	{
 		vnew.push_back((*iter)->getUUID());
 	}
@@ -131,35 +134,21 @@ void LLOutfitsList::refreshList(const LLUUID& category_id)
 	// Creating a vector of currently displayed sub-categories UUIDs.
 	for (outfits_map_t::const_iterator iter = mOutfitsMap.begin();
 		 iter != mOutfitsMap.end();
-		 iter++)
+		 ++iter)
 	{
 		vcur.push_back((*iter).first);
 	}
 
-	// Sorting both vectors to compare.
-	std::sort(vcur.begin(), vcur.end());
-	std::sort(vnew.begin(), vnew.end());
-
 	uuid_vec_t vadded;
 	uuid_vec_t vremoved;
 
-	uuid_vec_t::iterator it;
-	size_t maxsize = llmax(vcur.size(), vnew.size());
-	vadded.resize(maxsize);
-	vremoved.resize(maxsize);
-
-	// what to remove
-	it = set_difference(vcur.begin(), vcur.end(), vnew.begin(), vnew.end(), vremoved.begin());
-	vremoved.erase(it, vremoved.end());
-
-	// what to add
-	it = set_difference(vnew.begin(), vnew.end(), vcur.begin(), vcur.end(), vadded.begin());
-	vadded.erase(it, vadded.end());
+	// Create added and removed items vectors.
+	LLCommonUtils::computeDifference(vnew, vcur, vadded, vremoved);
 
 	// Handle added tabs.
 	for (uuid_vec_t::const_iterator iter = vadded.begin();
 		 iter != vadded.end();
-		 iter++)
+		 ++iter)
 	{
 		const LLUUID cat_id = (*iter);
 		LLViewerInventoryCategory *cat = gInventory.getCategory(cat_id);
@@ -175,7 +164,7 @@ void LLOutfitsList::refreshList(const LLUUID& category_id)
 		LLAccordionCtrlTab* tab = LLUICtrlFactory::defaultBuilder<LLAccordionCtrlTab>(accordionXmlNode, NULL, NULL);
 
 		// *TODO: LLUICtrlFactory::defaultBuilder does not use "display_children" from xml. Should be investigated.
-		tab->setDisplayChildren(false); 
+		tab->setDisplayChildren(false);
 		mAccordion->addCollapsibleCtrl(tab);
 
 		// Map the new tab with outfit category UUID.
@@ -185,6 +174,9 @@ void LLOutfitsList::refreshList(const LLUUID& category_id)
 		LLWearableItemsList* list  = tab->getChild<LLWearableItemsList>("wearable_items_list");
 		mCategoriesObserver->addCategory(cat_id, boost::bind(&LLWearableItemsList::updateList, list, cat_id));
 
+		// Setting drop down callback to monitor currently selected outfit.
+		tab->setDropDownStateChangedCallback(boost::bind(&LLOutfitsList::onTabExpandedCollapsed, this, list));
+
 		// Fetch the new outfit contents.
 		cat->fetch();
 
@@ -252,6 +244,14 @@ void LLOutfitsList::updateOutfitTab(const LLUUID& category_id)
 	}
 }
 
+void LLOutfitsList::onTabExpandedCollapsed(LLWearableItemsList* list)
+{
+	if (!list)
+		return;
+
+	// TODO: Add outfit selection handling.
+}
+
 void LLOutfitsList::setFilterSubString(const std::string& string)
 {
 	mFilterSubString = string;
diff --git a/indra/newview/lloutfitslist.h b/indra/newview/lloutfitslist.h
index f1756ce873b1e7339743465a9d7e947c80786fd8..de14c1541580a31cb29dba9662730b04b29a65b0 100644
--- a/indra/newview/lloutfitslist.h
+++ b/indra/newview/lloutfitslist.h
@@ -41,6 +41,17 @@ class LLAccordionCtrl;
 class LLAccordionCtrlTab;
 class LLWearableItemsList;
 
+/**
+ * @class LLOutfitsList
+ *
+ * A list of agents's outfits from "My Outfits" inventory category
+ * which displays each outfit in an accordion tab with a flat list
+ * of items inside it.
+ * Uses LLInventoryCategoriesObserver to monitor changes to "My Outfits"
+ * inventory category and refresh the outfits listed in it.
+ * This class is derived from LLInventoryObserver to know when inventory
+ * becomes usable and it is safe to request data from inventory model.
+ */
 class LLOutfitsList : public LLPanel, public LLInventoryObserver
 {
 public:
@@ -56,6 +67,8 @@ class LLOutfitsList : public LLPanel, public LLInventoryObserver
 	// Update tab displaying outfit identified by category_id.
 	void updateOutfitTab(const LLUUID& category_id);
 
+	void onTabExpandedCollapsed(LLWearableItemsList* list);
+
 	void setFilterSubString(const std::string& string);
 
 private:
diff --git a/indra/newview/llwearableitemslist.cpp b/indra/newview/llwearableitemslist.cpp
index ff309cbbc3333580edc1767353f8aeb11fe1516a..3d110dcc786c9b456a049d6c7243f4a1b84a646a 100644
--- a/indra/newview/llwearableitemslist.cpp
+++ b/indra/newview/llwearableitemslist.cpp
@@ -62,7 +62,10 @@ bool LLFindOutfitItems::operator()(LLInventoryCategory* cat,
 
 static const LLDefaultChildRegistry::Register<LLWearableItemsList> r("wearable_items_list");
 
-LLWearableItemsList::LLWearableItemsList(const LLFlatListView::Params& p)
+LLWearableItemsList::Params::Params()
+{}
+
+LLWearableItemsList::LLWearableItemsList(const LLWearableItemsList::Params& p)
 :	LLInventoryItemsList(p)
 {}
 
diff --git a/indra/newview/llwearableitemslist.h b/indra/newview/llwearableitemslist.h
index e3b011912ba109a628e9a1e57bc7960d1da7e7a2..e7ccba8e6c151b1ee64f8adebcfce0fe94341b2a 100644
--- a/indra/newview/llwearableitemslist.h
+++ b/indra/newview/llwearableitemslist.h
@@ -34,23 +34,32 @@
 
 #include "llpanel.h"
 
-#include "llassettype.h"
-
-#include "llinventorytype.h"
-
 // newview
 #include "llinventoryitemslist.h"
 
+/**
+ * @class LLWearableItemsList
+ *
+ * A flat list of wearable inventory items.
+ * Collects all items that can be a part of an outfit from
+ * an inventory category specified by UUID and displays them
+ * as a flat list.
+ */
 class LLWearableItemsList : public LLInventoryItemsList
 {
 public:
+	struct Params : public LLInitParam::Block<Params, LLInventoryItemsList::Params>
+	{
+		Params();
+	};
+
 	virtual ~LLWearableItemsList();
 
 	void updateList(const LLUUID& category_id);
 
 protected:
 	friend class LLUICtrlFactory;
-	LLWearableItemsList(const LLFlatListView::Params& p);
+	LLWearableItemsList(const LLWearableItemsList::Params& p);
 };
 
 #endif //LL_LLWEARABLEITEMSLIST_H
diff --git a/indra/newview/skins/default/xui/en/outfit_accordion_tab.xml b/indra/newview/skins/default/xui/en/outfit_accordion_tab.xml
index d00b1bfb7b8273e86b839ab32967728f0aa1d129..b3150bb98bd789ac7ad98ec0eaa933b737a7f64c 100644
--- a/indra/newview/skins/default/xui/en/outfit_accordion_tab.xml
+++ b/indra/newview/skins/default/xui/en/outfit_accordion_tab.xml
@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 <!-- *NOTE: mantipov: this xml is intended to be used inside panel_outfits_list.xml for each outfit folder-->
-<!-- All accordion tabs in the My Appearance/My Outfits panel will be created from this one at runtume-->
+<!-- All accordion tabs in the My Appearance/My Outfits panel will be created from this one at runtime-->
 <accordion_tab
  display_children="false"
  follows="all"
- height="40"
+ height="45"
  layout="topleft"
  name="Mockup Tab"
  title="Mockup Tab"