diff --git a/indra/llaudio/llaudioengine.cpp b/indra/llaudio/llaudioengine.cpp
index 238fbed1d963d839a2576bb356e0c541b46b536a..6cfcf54eb4d82ac6494df91a835d53a1dec2e8e8 100644
--- a/indra/llaudio/llaudioengine.cpp
+++ b/indra/llaudio/llaudioengine.cpp
@@ -1267,7 +1267,7 @@ void LLAudioEngine::assetCallback(const LLUUID &uuid, LLAssetType::EType type, v
 		    gAudioDecodeMgrp->addDecodeRequest(uuid);
 		}
 	}
-	gAudiop->mCurrentTransfer = LLUUID::null;
+	gAudiop->mCurrentTransfer.setNull();
 	gAudiop->startNextTransfer();
 }
 
diff --git a/indra/newview/llagent.cpp b/indra/newview/llagent.cpp
index 174b39b1fd354236f06af005aa1e3506f8dfff9e..0c21be8ac4401d425d2b1dc1b663f8ae02fdb707 100644
--- a/indra/newview/llagent.cpp
+++ b/indra/newview/llagent.cpp
@@ -2541,7 +2541,7 @@ void LLAgent::setStartPosition( U32 location_id )
 {
     LLViewerObject          *object;
 
-    if (gAgentID == LLUUID::null)
+    if (gAgentID.isNull())
     {
         return;
     }
diff --git a/indra/newview/llavataractions.cpp b/indra/newview/llavataractions.cpp
index 0e7ffbc90c8ee9150ff8ba37528baaafe7bb5cb9..4435180488aec871f7a191409dfc42996674cd0f 100644
--- a/indra/newview/llavataractions.cpp
+++ b/indra/newview/llavataractions.cpp
@@ -211,7 +211,7 @@ static void on_avatar_name_cache_start_im(const LLUUID& agent_id,
 {
 	std::string name = av_name.getDisplayName();
 	LLUUID session_id = gIMMgr->addSession(name, IM_NOTHING_SPECIAL, agent_id);
-	if (session_id != LLUUID::null)
+	if (session_id.notNull())
 	{
 		LLFloaterIMContainer::getInstance()->showConversation(session_id);
 	}
@@ -243,7 +243,7 @@ void LLAvatarActions::endIM(const LLUUID& id)
 		return;
 	
 	LLUUID session_id = gIMMgr->computeSessionID(IM_NOTHING_SPECIAL, id);
-	if (session_id != LLUUID::null)
+	if (session_id.notNull())
 	{
 		gIMMgr->leaveSession(session_id);
 	}
@@ -254,7 +254,7 @@ static void on_avatar_name_cache_start_call(const LLUUID& agent_id,
 {
 	std::string name = av_name.getDisplayName();
 	LLUUID session_id = gIMMgr->addSession(name, IM_NOTHING_SPECIAL, agent_id, true);
-	if (session_id != LLUUID::null)
+	if (session_id.notNull())
 	{
 		gIMMgr->startCall(session_id);
 	}
@@ -311,7 +311,7 @@ void LLAvatarActions::startAdhocCall(const uuid_vec_t& ids, const LLUUID& floate
 	const std::string title = LLTrans::getString("conference-title");
 	LLUUID session_id = gIMMgr->addSession(title, IM_SESSION_CONFERENCE_START,
 										   ids[0], id_array, true, floater_id);
-	if (session_id == LLUUID::null)
+	if (session_id.isNull())
 	{
 		return;
 	}
@@ -366,7 +366,7 @@ void LLAvatarActions::startConference(const uuid_vec_t& ids, const LLUUID& float
 	const std::string title = LLTrans::getString("conference-title");
 	LLUUID session_id = gIMMgr->addSession(title, IM_SESSION_CONFERENCE_START, ids[0], id_array, false, floater_id);
 
-	if (session_id == LLUUID::null)
+	if (session_id.isNull())
 	{
 		return;
 	}
diff --git a/indra/newview/llfavoritesbar.cpp b/indra/newview/llfavoritesbar.cpp
index 0f39d773787c2743080e83b86b33829bff2eaade..61b25e7693fd9f998baa0e65342df8d74e96bc36 100644
--- a/indra/newview/llfavoritesbar.cpp
+++ b/indra/newview/llfavoritesbar.cpp
@@ -1432,7 +1432,7 @@ void LLFavoritesBarCtrl::onEndDrag()
 
 BOOL LLFavoritesBarCtrl::handleHover(S32 x, S32 y, MASK mask)
 {
-	if (mDragItemId != LLUUID::null && mStartDrag)
+	if (mDragItemId.notNull() && mStartDrag)
 	{
 		S32 screenX, screenY;
 		localPointToScreen(x, y, &screenX, &screenY);
diff --git a/indra/newview/llfloaterconversationpreview.cpp b/indra/newview/llfloaterconversationpreview.cpp
index 580a3f26103792a4f52cc63feed51a0e694324e7..d76793bfd296bdac3a2bbf503fa98d147f11baf5 100644
--- a/indra/newview/llfloaterconversationpreview.cpp
+++ b/indra/newview/llfloaterconversationpreview.cpp
@@ -72,7 +72,7 @@ BOOL LLFloaterConversationPreview::postBuild()
 		name = mCompleteName;
 		file = mAccountName;
 	}
-	else if (mSessionID != LLUUID::null && conv)
+	else if (mSessionID.notNull() && conv)
 	{
 		name = conv->getConversationName();
 		file = conv->getHistoryFileName();
diff --git a/indra/newview/llfloaterimcontainer.cpp b/indra/newview/llfloaterimcontainer.cpp
index 18cd4f6770d71f80210eb2e310152b506ca99b16..2b0e491a9febb5b11861bc2d633537db8cb8f2c2 100644
--- a/indra/newview/llfloaterimcontainer.cpp
+++ b/indra/newview/llfloaterimcontainer.cpp
@@ -165,7 +165,7 @@ void LLFloaterIMContainer::sessionRemoved(const LLUUID& session_id)
 // static
 void LLFloaterIMContainer::onCurrentChannelChanged(const LLUUID& session_id)
 {
-    if (session_id != LLUUID::null)
+    if (session_id.notNull())
     {
     	LLFloaterIMContainer::getInstance()->showConversation(session_id);
     }
diff --git a/indra/newview/llfloaterinspect.cpp b/indra/newview/llfloaterinspect.cpp
index 5ae9abe67b9cc4a5281c6db217305cc7aedc97e3..39c27a241da02fc68acd3b2eb541e23611d29ffe 100644
--- a/indra/newview/llfloaterinspect.cpp
+++ b/indra/newview/llfloaterinspect.cpp
@@ -170,7 +170,7 @@ void LLFloaterInspect::onClickOwnerProfile()
 
 void LLFloaterInspect::onSelectObject()
 {
-	if(LLFloaterInspect::getSelectedUUID() != LLUUID::null)
+	if(LLFloaterInspect::getSelectedUUID().notNull())
 	{
 		if (!RlvActions::isRlvEnabled())
 		{
@@ -256,7 +256,7 @@ void LLFloaterInspect::onSelectObject()
 
 //void LLFloaterInspect::onSelectObject()
 //{
-//	if(LLFloaterInspect::getSelectedUUID() != LLUUID::null)
+//	if(LLFloaterInspect::getSelectedUUID().notNull())
 //	{
 //		getChildView("button owner")->setEnabled(true);
 //		getChildView("button creator")->setEnabled(true);
diff --git a/indra/newview/llfloaterpreference.cpp b/indra/newview/llfloaterpreference.cpp
index 22f229835a070f383fa8e7a0d77f9726c99b1eed..f12824c09ed31e6990cb25060ec5f708bcd303bd 100644
--- a/indra/newview/llfloaterpreference.cpp
+++ b/indra/newview/llfloaterpreference.cpp
@@ -365,7 +365,7 @@ void LLFloaterPreference::processProperties( void* pData, EAvatarProcessorType t
 	if ( APT_PROPERTIES == type )
 	{
 		const LLAvatarData* pAvatarData = static_cast<const LLAvatarData*>( pData );
-		if (pAvatarData && (gAgent.getID() == pAvatarData->avatar_id) && (pAvatarData->avatar_id != LLUUID::null))
+		if (pAvatarData && (gAgent.getID() == pAvatarData->avatar_id) && (pAvatarData->avatar_id.notNull()))
 		{
 			storeAvatarProperties( pAvatarData );
 			processProfileProperties( pAvatarData );
diff --git a/indra/newview/llgroupactions.cpp b/indra/newview/llgroupactions.cpp
index db579f95cf05a25506f84e2ae249e686cf670836..4d03e5e02b5f2fc85543ca55f6e7a895ce66ce1d 100644
--- a/indra/newview/llgroupactions.cpp
+++ b/indra/newview/llgroupactions.cpp
@@ -227,7 +227,7 @@ void LLGroupActions::startCall(const LLUUID& group_id)
 // [/RLVa:KB]
 
 	LLUUID session_id = gIMMgr->addSession(gdata.mName, IM_SESSION_GROUP_START, group_id, true);
-	if (session_id == LLUUID::null)
+	if (session_id.isNull())
 	{
 		LL_WARNS() << "Error adding session" << LL_ENDL;
 		return;
@@ -496,7 +496,7 @@ LLUUID LLGroupActions::startIM(const LLUUID& group_id)
 			group_data.mName,
 			IM_SESSION_GROUP_START,
 			group_id);
-		if (session_id != LLUUID::null)
+		if (session_id.notNull())
 		{
 			LLFloaterIMContainer::getInstance()->showConversation(session_id);
 		}
@@ -520,7 +520,7 @@ static void close_group_im(const LLUUID& group_id, LLIMModel::LLIMSession::SClos
 		return;
 	
 	LLUUID session_id = gIMMgr->computeSessionID(IM_SESSION_GROUP_START, group_id);
-	if (session_id != LLUUID::null)
+	if (session_id.notNull())
 	{
 		LLIMModel::LLIMSession* pIMSession = LLIMModel::getInstance()->findIMSession(session_id);
 		if (pIMSession)
@@ -557,7 +557,7 @@ void LLGroupActions::endIM(const LLUUID& group_id)
 //		return;
 //	
 //	LLUUID session_id = gIMMgr->computeSessionID(IM_SESSION_GROUP_START, group_id);
-//	if (session_id != LLUUID::null)
+//	if (session_id.notNull())
 //	{
 //		gIMMgr->leaveSession(session_id);
 //	}
diff --git a/indra/newview/llgroupmgr.cpp b/indra/newview/llgroupmgr.cpp
index 82998b4f418808226c4500ae2ccfe5184098d7ee..6ee83b4c735fc5d03955e4765d9c1afcfc657d9e 100644
--- a/indra/newview/llgroupmgr.cpp
+++ b/indra/newview/llgroupmgr.cpp
@@ -843,7 +843,7 @@ void LLGroupMgr::clearGroupData(const LLUUID& group_id)
 
 void LLGroupMgr::addObserver(LLGroupMgrObserver* observer) 
 { 
-	if( observer->getID() != LLUUID::null )
+	if( observer->getID().notNull())
 		mObservers.insert(std::pair<LLUUID, LLGroupMgrObserver*>(observer->getID(), observer));
 }
 
diff --git a/indra/newview/llinventorybridge.cpp b/indra/newview/llinventorybridge.cpp
index 3416b7c8abeeca0d701049263c06f14a780caded..3795b27dd22f1e83733c70396db3b52d216577c3 100644
--- a/indra/newview/llinventorybridge.cpp
+++ b/indra/newview/llinventorybridge.cpp
@@ -5937,7 +5937,7 @@ void LLCallingCardBridge::performAction(LLInventoryModel* model, std::string act
 // [/RLVa:KB]
 
 			LLUUID session_id = gIMMgr->addSession(callingcard_name, IM_NOTHING_SPECIAL, item->getCreatorUUID());
-			if (session_id != LLUUID::null)
+			if (session_id.notNull())
 			{
 				LLFloaterIMContainer::getInstance()->showConversation(session_id);
 			}
diff --git a/indra/newview/llinventoryfilter.cpp b/indra/newview/llinventoryfilter.cpp
index 587bd4183b883171a4596e7d854f1c5ab354f170..8baba6e6d5dc6184cfe238b7ec92836a394f5026 100644
--- a/indra/newview/llinventoryfilter.cpp
+++ b/indra/newview/llinventoryfilter.cpp
@@ -836,7 +836,7 @@ void LLInventoryFilter::setFilterNoMarketplaceFolder()
 
 void LLInventoryFilter::setFilterUUID(const LLUUID& object_id)
 {
-	if (mFilterOps.mFilterUUID == LLUUID::null)
+	if (mFilterOps.mFilterUUID.isNull())
 	{
 		setModified(FILTER_MORE_RESTRICTIVE);
 	}
diff --git a/indra/newview/llinventorymodel.cpp b/indra/newview/llinventorymodel.cpp
index bec400acbc7301cafeb3d4daabdf870794dd7bca..a6a597c49958be46831dab6a85db39a9e9301be7 100644
--- a/indra/newview/llinventorymodel.cpp
+++ b/indra/newview/llinventorymodel.cpp
@@ -2608,7 +2608,7 @@ void LLInventoryModel::buildParentChildMap()
 		}
 	}
 
-	const BOOL COF_exists = (findCategoryUUIDForType(LLFolderType::FT_CURRENT_OUTFIT, FALSE) != LLUUID::null);
+	const BOOL COF_exists = (findCategoryUUIDForType(LLFolderType::FT_CURRENT_OUTFIT, FALSE).notNull());
 	sFirstTimeInViewer2 = !COF_exists || gAgent.isFirstLogin();
 
 
diff --git a/indra/newview/llinventoryobserver.cpp b/indra/newview/llinventoryobserver.cpp
index 26d7a7a28a80ec86be340d7d6489d581d2b6def0..8ef8e0cc6a3ccd76a3b86096d8ffe6d05f32c9e7 100644
--- a/indra/newview/llinventoryobserver.cpp
+++ b/indra/newview/llinventoryobserver.cpp
@@ -71,7 +71,7 @@ LLInventoryObserver::~LLInventoryObserver()
 LLInventoryFetchObserver::LLInventoryFetchObserver(const LLUUID& id)
 {
 	mIDs.clear();
-	if (id != LLUUID::null)
+	if (id.notNull())
 	{
 		setFetchID(id);
 	}
diff --git a/indra/newview/llinventorypanel.cpp b/indra/newview/llinventorypanel.cpp
index 4d8b6ef1a8a725607146a44ab30d151567fa7e39..a3916d7da6fe8e0dea7b74abd36f1efe62f761f9 100644
--- a/indra/newview/llinventorypanel.cpp
+++ b/indra/newview/llinventorypanel.cpp
@@ -1488,7 +1488,7 @@ bool LLInventoryPanel::beginIMSession()
 	}
 // [/RLVa:KB]
 //	LLUUID session_id = gIMMgr->addSession(name, type, members[0], members);
-//	if (session_id != LLUUID::null)
+//	if (session_id.notNull())
 //	{
 //		LLFloaterIMContainer::getInstance()->showConversation(session_id);
 //	}
diff --git a/indra/newview/llpanelgroup.cpp b/indra/newview/llpanelgroup.cpp
index 38531b82b531ed1177275272f06e47c929aa8bf8..392276312dfcfa0f8f2c96e18e4a257c0f50ba21 100644
--- a/indra/newview/llpanelgroup.cpp
+++ b/indra/newview/llpanelgroup.cpp
@@ -121,7 +121,7 @@ void LLPanelGroup::onOpen(const LLSD& key)
 
 	if(str_action == "refresh")
 	{
-		if(mID == group_id || group_id == LLUUID::null)
+		if(mID == group_id || group_id.isNull())
 			refreshData();
 	}
 	else if(str_action == "close")
@@ -365,7 +365,7 @@ void LLPanelGroup::setGroupID(const LLUUID& group_id)
 	LLButton* button_chat = findChild<LLButton>("btn_chat");
 
 
-	bool is_null_group_id = group_id == LLUUID::null;
+	bool is_null_group_id = group_id.isNull();
 	if(button_apply)
 		button_apply->setVisible(!is_null_group_id);
 	if(button_refresh)
diff --git a/indra/newview/llpanelgroupexperiences.cpp b/indra/newview/llpanelgroupexperiences.cpp
index 6c404992081ff51648159da97b22c710de6bf582..10ff6ef269acf2dd694745c69a62027ff6be4b82 100644
--- a/indra/newview/llpanelgroupexperiences.cpp
+++ b/indra/newview/llpanelgroupexperiences.cpp
@@ -67,7 +67,7 @@ BOOL LLPanelGroupExperiences::postBuild()
 
 void LLPanelGroupExperiences::activate()
 {
-	if ((getGroupID() == LLUUID::null) || gDisconnected)
+	if ((getGroupID().isNull()) || gDisconnected)
 	{
 		return;
 	}
@@ -80,7 +80,7 @@ void LLPanelGroupExperiences::setGroupID(const LLUUID& id)
 {
 	LLPanelGroupTab::setGroupID(id);
 
-	if(id == LLUUID::null)
+	if(id.isNull())
 	{
 		return;
 	}
diff --git a/indra/newview/llpanelgroupgeneral.cpp b/indra/newview/llpanelgroupgeneral.cpp
index 962241af0b75320a783a7d2aa0194ebc755231a1..2272f4c1d8d260e95eeeb4b16f47700f35c603ed 100644
--- a/indra/newview/llpanelgroupgeneral.cpp
+++ b/indra/newview/llpanelgroupgeneral.cpp
@@ -797,7 +797,7 @@ void LLPanelGroupGeneral::setGroupID(const LLUUID& id)
 {
 	LLPanelGroupTab::setGroupID(id);
 
-	if(id == LLUUID::null)
+	if(id.isNull())
 	{
 		reset();
 		return;
diff --git a/indra/newview/llpanelgroupinvite.cpp b/indra/newview/llpanelgroupinvite.cpp
index d6b66ee6225a7a961109a46f4bf688aafa326e39..2b2b9408d7fa0021e16d0a5dc9ffa6c7a9a2b933 100644
--- a/indra/newview/llpanelgroupinvite.cpp
+++ b/indra/newview/llpanelgroupinvite.cpp
@@ -288,7 +288,7 @@ void LLPanelGroupInvite::impl::addRoleNames(LLGroupMgrGroupData* gdatap)
 				// Add all roles user is in
 				|| (can_assign_limited && member_data && member_data->isInRole(role_id))
 				// Everyone role.
-				|| role_id == LLUUID::null )
+				|| role_id.isNull() )
 			{
 				mRoleNames->add(rd.mRoleName,
 								role_id,
diff --git a/indra/newview/llpanelobject.cpp b/indra/newview/llpanelobject.cpp
index da6547da59cd6f9a0d59dabf8d0719db58f62cf9..039e7f4a6cd48f31bcac51295e7b0a8809a6778f 100644
--- a/indra/newview/llpanelobject.cpp
+++ b/indra/newview/llpanelobject.cpp
@@ -2206,7 +2206,7 @@ BOOL LLPanelObject::onDropSculpt(LLInventoryItem* item)
 
 void LLPanelObject::onCancelSculpt(const LLSD& data)
 {
-	if(mSculptTextureRevert == LLUUID::null)
+	if(mSculptTextureRevert.isNull())
 	{
 		mSculptTextureRevert = LLUUID(SCULPT_DEFAULT_TEXTURE);
 	}
diff --git a/indra/newview/llselectmgr.cpp b/indra/newview/llselectmgr.cpp
index ad2cd365bb0f3930afb62f4a2bf9eddf51d0da59..5df6033cc946442b76b7d366772dd4978f34bb4d 100644
--- a/indra/newview/llselectmgr.cpp
+++ b/indra/newview/llselectmgr.cpp
@@ -6793,7 +6793,7 @@ void LLSelectMgr::updateSelectionCenter()
 
 	}
 	
-	if ( !(gAgentID == LLUUID::null)) 
+	if (gAgentID.notNull())
 	{
 		LLTool		*tool = LLToolMgr::getInstanceFast()->getCurrentTool();
 		if (mShowSelection)
diff --git a/indra/newview/llstartup.cpp b/indra/newview/llstartup.cpp
index 3bf4cd099fe5eba41444ca0ae729e23f1d56932f..b7c323c5dc422ef6ae003cd4961e3d8e2fce38d4 100644
--- a/indra/newview/llstartup.cpp
+++ b/indra/newview/llstartup.cpp
@@ -1271,7 +1271,7 @@ bool idle_startup()
 		set_startup_status(0.30f, LLTrans::getString("LoginInitializingWorld"), gAgent.mMOTD);
 		display_startup();
 		// We should have an agent id by this point.
-		llassert(!(gAgentID == LLUUID::null));
+		llassert(gAgentID.notNull());
 
 		// Finish agent initialization.  (Requires gSavedSettings, builds camera)
 		gAgent.init();
diff --git a/indra/newview/llstylemap.cpp b/indra/newview/llstylemap.cpp
index 43fe37ac77ba390ff7452ec5b3a3956759c072c1..9e2bc0c6261a6276aa317b1e23684659ffc719b2 100644
--- a/indra/newview/llstylemap.cpp
+++ b/indra/newview/llstylemap.cpp
@@ -40,7 +40,7 @@ const LLStyle::Params &LLStyleMap::lookupAgent(const LLUUID &source)
 	if (mMap.find(source) == mMap.end())
 	{
 		LLStyle::Params style_params;
-		if (source != LLUUID::null)
+		if (source.notNull())
 		{
 			style_params.color.control = "HTMLLinkColor";
 			style_params.readonly_color.control = "HTMLLinkColor";
@@ -60,7 +60,7 @@ const LLStyle::Params &LLStyleMap::lookup(const LLUUID& id, const std::string& l
 	{
 		LLStyle::Params style_params;
 
-		if (id != LLUUID::null && !link.empty())
+		if (id.notNull() && !link.empty())
 		{
 			style_params.color.control = "HTMLLinkColor";
 			style_params.readonly_color.control = "HTMLLinkColor";
diff --git a/indra/newview/llviewergesture.cpp b/indra/newview/llviewergesture.cpp
index 1a57225ce8766eac20a058424e91dd32dbf0e7f9..c502f3340024b3dcc965e53f2abf60ba8bcd252b 100644
--- a/indra/newview/llviewergesture.cpp
+++ b/indra/newview/llviewergesture.cpp
@@ -104,7 +104,7 @@ BOOL LLViewerGesture::trigger(const std::string &trigger_string)
 // private
 void LLViewerGesture::doTrigger( BOOL send_chat )
 {
-	if (mSoundItemID != LLUUID::null)
+	if (mSoundItemID.notNull())
 	{
 		LLViewerInventoryItem *item;
 		item = gInventory.getItem(mSoundItemID);
diff --git a/indra/newview/llviewermedia.cpp b/indra/newview/llviewermedia.cpp
index 64e7c555c7d0b7d94b843d0086afa6cba8271921..637239d7bd180b5b906be78bd53be5117a8c3d5f 100644
--- a/indra/newview/llviewermedia.cpp
+++ b/indra/newview/llviewermedia.cpp
@@ -2101,7 +2101,7 @@ void LLViewerMediaImpl::updateVolume()
 			}
 		}
 
-		if (sOnlyAudibleTextureID == LLUUID::null || sOnlyAudibleTextureID == mTextureId)
+		if (sOnlyAudibleTextureID.isNull() || sOnlyAudibleTextureID == mTextureId)
 		{
 			mMediaSource->setVolume(volume);
 		}
diff --git a/indra/newview/llviewermenu.cpp b/indra/newview/llviewermenu.cpp
index 6e5e8d33719e301fc637c8f42c98e803bfebaa93..f39cd74efa4238ffe2c83db20bdab3734e020a65 100644
--- a/indra/newview/llviewermenu.cpp
+++ b/indra/newview/llviewermenu.cpp
@@ -3093,7 +3093,7 @@ bool enable_mute_particle()
 {
 	const LLPickInfo& pick = LLToolPie::getInstance()->getPick();
 
-	return pick.mParticleOwnerID != LLUUID::null && pick.mParticleOwnerID != gAgent.getID();
+	return pick.mParticleOwnerID.notNull() && pick.mParticleOwnerID != gAgent.getID();
 }
 
 // mutually exclusive - show either edit option or build in menu
diff --git a/indra/newview/llviewermessage.cpp b/indra/newview/llviewermessage.cpp
index a13e9044193af62866892190531f6e4bf004faf6..d70650242faad30c7a1138c671a25ccf4b3186f6 100644
--- a/indra/newview/llviewermessage.cpp
+++ b/indra/newview/llviewermessage.cpp
@@ -4004,7 +4004,7 @@ void process_kill_object(LLMessageSystem *mesgsys, void **user_data)
 		mesgsys->getU32Fast(_PREHASH_ObjectData, _PREHASH_ID, local_id, i);
 
 		LLViewerObjectList::getUUIDFromLocal(id, local_id, ip, port); 
-		if (id == LLUUID::null)
+		if (id.isNull())
 		{
 			LL_DEBUGS("Messaging") << "Unknown kill for local " << local_id << LL_ENDL;
 			continue;
diff --git a/indra/newview/llviewerobject.cpp b/indra/newview/llviewerobject.cpp
index d346932514786d9f6ed2e6fd7c9d0e7f78db18de..0ebd53268d224bb1205add090af6ea4761d8c999 100644
--- a/indra/newview/llviewerobject.cpp
+++ b/indra/newview/llviewerobject.cpp
@@ -4964,7 +4964,7 @@ S32 LLViewerObject::setTETextureCore(const U8 te, LLViewerTexture *image)
 	const LLUUID& uuid = image->getID();
 	S32 retval = 0;
 	if (uuid != getTE(te)->getID() ||
-		uuid == LLUUID::null)
+		uuid.isNull())
 	{
 		retval = LLPrimitive::setTETexture(te, uuid);
 		LLViewerTexture* baked_texture = getBakedTextureForMagicId(uuid);
@@ -4984,7 +4984,7 @@ S32 LLViewerObject::setTENormalMapCore(const U8 te, LLViewerTexture *image)
 	S32 retval = TEM_CHANGE_TEXTURE;
 	const LLUUID& uuid = image ? image->getID() : LLUUID::null;
 	if (uuid != getTE(te)->getID() ||
-		uuid == LLUUID::null)
+		uuid.isNull())
 	{
 		LLTextureEntry* tep = getTE(te);
 		LLMaterial* mat = NULL;
@@ -5007,7 +5007,7 @@ S32 LLViewerObject::setTESpecularMapCore(const U8 te, LLViewerTexture *image)
 	S32 retval = TEM_CHANGE_TEXTURE;
 	const LLUUID& uuid = image ? image->getID() : LLUUID::null;
 	if (uuid != getTE(te)->getID() ||
-		uuid == LLUUID::null)
+		uuid.isNull())
 	{
 		LLTextureEntry* tep = getTE(te);
 		LLMaterial* mat = NULL;
@@ -5065,14 +5065,14 @@ S32 LLViewerObject::setTETexture(const U8 te, const LLUUID& uuid)
 
 S32 LLViewerObject::setTENormalMap(const U8 te, const LLUUID& uuid)
 {
-	LLViewerFetchedTexture *image = (uuid == LLUUID::null) ? NULL : LLViewerTextureManager::getFetchedTexture(
+	LLViewerFetchedTexture *image = (uuid.isNull()) ? NULL : LLViewerTextureManager::getFetchedTexture(
 		uuid, FTT_DEFAULT, TRUE, LLGLTexture::BOOST_ALM, LLViewerTexture::LOD_TEXTURE, 0, 0, LLHost());
 	return setTENormalMapCore(te, image);
 }
 
 S32 LLViewerObject::setTESpecularMap(const U8 te, const LLUUID& uuid)
 {
-	LLViewerFetchedTexture *image = (uuid == LLUUID::null) ? NULL : LLViewerTextureManager::getFetchedTexture(
+	LLViewerFetchedTexture *image = (uuid.isNull()) ? NULL : LLViewerTextureManager::getFetchedTexture(
 		uuid, FTT_DEFAULT, TRUE, LLGLTexture::BOOST_ALM, LLViewerTexture::LOD_TEXTURE, 0, 0, LLHost());
 	return setTESpecularMapCore(te, image);
 }
@@ -5766,7 +5766,7 @@ void LLViewerObject::setParticleSource(const LLPartSysData& particle_parameters,
 		if (mPartSourcep->getImage()->getID() != mPartSourcep->mPartSysData.mPartImageID)
 		{
 			LLViewerTexture* image;
-			if (mPartSourcep->mPartSysData.mPartImageID == LLUUID::null)
+			if (mPartSourcep->mPartSysData.mPartImageID.isNull())
 			{
 				image = LLViewerFetchedTexture::sPixieSmallImagep;
 			}
@@ -5815,7 +5815,7 @@ void LLViewerObject::unpackParticleSource(const S32 block_num, const LLUUID& own
 		if (mPartSourcep->getImage()->getID() != mPartSourcep->mPartSysData.mPartImageID)
 		{
 			LLViewerTexture* image;
-			if (mPartSourcep->mPartSysData.mPartImageID == LLUUID::null)
+			if (mPartSourcep->mPartSysData.mPartImageID.isNull())
 			{
 				image = LLViewerFetchedTexture::sPixieSmallImagep;
 			}
@@ -5862,7 +5862,7 @@ void LLViewerObject::unpackParticleSource(LLDataPacker &dp, const LLUUID& owner_
 		if (mPartSourcep->getImage()->getID() != mPartSourcep->mPartSysData.mPartImageID)
 		{
 			LLViewerTexture* image;
-			if (mPartSourcep->mPartSysData.mPartImageID == LLUUID::null)
+			if (mPartSourcep->mPartSysData.mPartImageID.isNull())
 			{
 				image = LLViewerFetchedTexture::sPixieSmallImagep;
 			}
diff --git a/indra/newview/llviewerobjectlist.cpp b/indra/newview/llviewerobjectlist.cpp
index b3cf06efc44266dd6e36c02da06c771db67c6c6a..ecf7c6f5dc58db31a37c86bbd33fb2b73d6d38e5 100644
--- a/indra/newview/llviewerobjectlist.cpp
+++ b/indra/newview/llviewerobjectlist.cpp
@@ -2097,7 +2097,7 @@ LLViewerObject *LLViewerObjectList::createObject(const LLPCode pcode, LLViewerRe
 {
 	
 	LLUUID fullid;
-	if (uuid == LLUUID::null)
+	if (uuid.isNull())
 	{
 		fullid.generate();
 	}
diff --git a/indra/newview/llviewerpartsource.cpp b/indra/newview/llviewerpartsource.cpp
index f20175436c393c275b000d89a79a8d57dc234c8c..f8100a0741ee0df227417c0fbed8475027d15bc8 100644
--- a/indra/newview/llviewerpartsource.cpp
+++ b/indra/newview/llviewerpartsource.cpp
@@ -132,7 +132,7 @@ void LLViewerPartSourceScript::update(const F32 dt)
 	if( mIsSuspended )
 		return;
 
-	if (mOwnerAvatarp.isNull() && mOwnerUUID != LLUUID::null)
+	if (mOwnerAvatarp.isNull() && mOwnerUUID.notNull())
 	{
 		mOwnerAvatarp = find_avatar(mOwnerUUID);
 	}
diff --git a/indra/test/llpermissions_tut.cpp b/indra/test/llpermissions_tut.cpp
index e6ccd5ecb7b107e3394a919d4439e06d5f05b1fd..995c7e4444a46163c85a495cf03e0045e9e06a21 100644
--- a/indra/test/llpermissions_tut.cpp
+++ b/indra/test/llpermissions_tut.cpp
@@ -53,8 +53,8 @@ namespace tut
 		LLUUID	uuid2 = permissions.getGroup();
 		LLUUID	uuid3 = permissions.getLastOwner(); 
 
-		ensure("LLPermission Get Functions failed", (uuid == LLUUID::null && uuid1 == LLUUID::null && 
-			uuid2 == LLUUID::null && uuid3 == LLUUID::null));
+		ensure("LLPermission Get Functions failed", (uuid.isNull() && uuid1.isNull() &&
+			uuid2.isNull() && uuid3.isNull()));
 		ensure("LLPermission Get Functions failed", (permissions.getMaskBase() == PERM_ALL && permissions.getMaskOwner() == PERM_ALL && 
 			permissions.getMaskGroup() == PERM_ALL && permissions.getMaskEveryone() == PERM_ALL && permissions.getMaskNextOwner() == PERM_ALL));
 		ensure("Ownership functions failed", ((! permissions.isGroupOwned()) && (! permissions.isOwned())));