From 6b0977b0b831f0ffdef3d13fc9d1d56bc393bbaf Mon Sep 17 00:00:00 2001
From: AngryGamer <AngryGamer@github.com>
Date: Sun, 28 May 2017 16:41:38 -0700
Subject: [PATCH] Fix rapid swapping between two tabs during tab drag and drop.

Closes 3328, Fixes #3017, fixes #2771
---
 PowerEditor/src/WinControls/TabBar/TabBar.cpp | 11 +++++++++++
 PowerEditor/src/WinControls/TabBar/TabBar.h   |  1 +
 2 files changed, 12 insertions(+)

diff --git a/PowerEditor/src/WinControls/TabBar/TabBar.cpp b/PowerEditor/src/WinControls/TabBar/TabBar.cpp
index 0980cef4..e4fab7a2 100644
--- a/PowerEditor/src/WinControls/TabBar/TabBar.cpp
+++ b/PowerEditor/src/WinControls/TabBar/TabBar.cpp
@@ -1194,13 +1194,24 @@ void TabBarPlus::exchangeItemData(POINT point)
 
 		if (nTab != _nTabDragged)
 		{
+			if (_previousTabSwapped == nTab)
+			{
+				return;
+			}
+
 			exchangeTabItemData(_nTabDragged, nTab);
+			_previousTabSwapped = _nTabDragged;
 			_nTabDragged = nTab;
 		}
+		else
+		{
+			_previousTabSwapped = -1;
+		}
 	}
 	else
 	{
 		//::SetCursor(::LoadCursor(_hInst, MAKEINTRESOURCE(IDC_DRAG_TAB)));
+		_previousTabSwapped = -1;
 		_isDraggingInside = false;
 	}
 
diff --git a/PowerEditor/src/WinControls/TabBar/TabBar.h b/PowerEditor/src/WinControls/TabBar/TabBar.h
index 2ed4b006..0790a316 100644
--- a/PowerEditor/src/WinControls/TabBar/TabBar.h
+++ b/PowerEditor/src/WinControls/TabBar/TabBar.h
@@ -229,6 +229,7 @@ protected:
 	bool _isDraggingInside = false;
     int _nSrcTab = -1;
 	int _nTabDragged = -1;
+	int _previousTabSwapped = -1;
 	POINT _draggingPoint; // coordinate of Screen
 	WNDPROC _tabBarDefaultProc = nullptr;