diff --git a/indra/newview/CMakeLists.txt b/indra/newview/CMakeLists.txt
index 630902c48f5dcafdcc0d3d9a8e93de4b1e4bdb00..d6622f164e68e62aaac18b67eb3efb9ba9b14019 100644
--- a/indra/newview/CMakeLists.txt
+++ b/indra/newview/CMakeLists.txt
@@ -203,6 +203,7 @@ set(viewer_SOURCE_FILES
     llfloatersearch.cpp
     llfloatersellland.cpp
     llfloatersettingsdebug.cpp
+    llfloatersidetraytab.cpp
     llfloatersnapshot.cpp
     llfloatertelehub.cpp
     llfloatertestinspectors.cpp
@@ -727,6 +728,7 @@ set(viewer_HEADER_FILES
     llfloatersearch.h
     llfloatersellland.h
     llfloatersettingsdebug.h
+    llfloatersidetraytab.h
     llfloatersnapshot.h
     llfloatertelehub.h
     llfloatertestinspectors.h
diff --git a/indra/newview/llfloatersidetraytab.cpp b/indra/newview/llfloatersidetraytab.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f13b4db3a062e45679a17be31ff39f1d1ff1bd4f
--- /dev/null
+++ b/indra/newview/llfloatersidetraytab.cpp
@@ -0,0 +1,45 @@
+/** 
+ * @file llfloatersidetraytab.cpp
+ * @brief LLFloaterSideTrayTab class definition
+ *
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "llviewerprecompiledheaders.h"
+
+#include "llfloatersidetraytab.h"
+
+// newview includes
+#include "lltransientfloatermgr.h"
+
+LLFloaterSideTrayTab::LLFloaterSideTrayTab(const LLSD& key, const Params& params)
+:	LLFloater(key, params)
+{
+	// Prevent transient floaters (e.g. IM windows) from hiding
+	// when this floater is clicked.
+	LLTransientFloaterMgr::getInstance()->addControlView(LLTransientFloaterMgr::GLOBAL, this);
+}
+
+LLFloaterSideTrayTab::~LLFloaterSideTrayTab()
+{
+	LLTransientFloaterMgr::getInstance()->removeControlView(LLTransientFloaterMgr::GLOBAL, this);
+}
diff --git a/indra/newview/llfloatersidetraytab.h b/indra/newview/llfloatersidetraytab.h
new file mode 100644
index 0000000000000000000000000000000000000000..e47f82e8ba250c47f0ad890ae2f4c69cc2f116bd
--- /dev/null
+++ b/indra/newview/llfloatersidetraytab.h
@@ -0,0 +1,47 @@
+/** 
+ * @file llfloatersidetraytab.h
+ * @brief LLFloaterSideTrayTab class definition
+ *
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLFLOATERSIDETRAYTAB_H
+#define LL_LLFLOATERSIDETRAYTAB_H
+
+#include "llfloater.h"
+
+/**
+ * When a side tray tab gets detached, it's wrapped in an instance of this class.
+ *
+ * This class helps to make sure that clicking a detached side tray tab doesn't
+ * make transient floaters (e.g. IM windows) hide, so that it's possible to
+ * drag an inventory item from detached My Inventory window to a docked IM window,
+ * i.e. share the item (see VWR-22891).
+ */
+class LLFloaterSideTrayTab : public LLFloater
+{
+public:
+	LLFloaterSideTrayTab(const LLSD& key, const Params& params = getDefaultParams());
+	~LLFloaterSideTrayTab();
+};
+
+#endif // LL_LLFLOATERSIDETRAYTAB_H
diff --git a/indra/newview/llviewerfloaterreg.cpp b/indra/newview/llviewerfloaterreg.cpp
index 87282985751572617025722faa36479c19d26ac2..b6f2d34663ba1ab5b600c45750718b8e502750b6 100644
--- a/indra/newview/llviewerfloaterreg.cpp
+++ b/indra/newview/llviewerfloaterreg.cpp
@@ -86,6 +86,7 @@
 #include "llfloaterscriptlimits.h"
 #include "llfloatersellland.h"
 #include "llfloatersettingsdebug.h"
+#include "llfloatersidetraytab.h"
 #include "llfloatersnapshot.h"
 #include "llfloatertelehub.h"
 #include "llfloatertestinspectors.h"
@@ -234,7 +235,7 @@ void LLViewerFloaterReg::registerFloaters()
 	LLFloaterReg::add("script_limits", "floater_script_limits.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterScriptLimits>);
 	LLFloaterReg::add("sell_land", "floater_sell_land.xml", &LLFloaterSellLand::buildFloater);
 	LLFloaterReg::add("settings_debug", "floater_settings_debug.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterSettingsDebug>);
-	LLFloaterReg::add("side_bar_tab", "floater_side_bar_tab.xml",&LLFloaterReg::build<LLFloater>);
+	LLFloaterReg::add("side_bar_tab", "floater_side_bar_tab.xml", &LLFloaterReg::build<LLFloaterSideTrayTab>);
 	LLFloaterReg::add("stats", "floater_stats.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloater>);
 	LLFloaterReg::add("start_queue", "floater_script_queue.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterRunQueue>);
 	LLFloaterReg::add("stop_queue", "floater_script_queue.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterNotRunQueue>);