From 7b433605f93a368647e25d190a62faabf8be256d Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Wed, 25 Apr 2018 15:38:19 +0200
Subject: [PATCH] Viewport: Avoid creating viewport on drag (fix
 cc882b07239b28b1dab6d46af72d3a463c92254a)

---
 imgui.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/imgui.cpp b/imgui.cpp
index f0689f66..19bdfe0d 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -6229,7 +6229,8 @@ static void ImGui::UpdateSelectWindowViewport(ImGuiWindow* window)
     }
     else if (!window->ViewportOwned && g.MovingWindow && g.MovingWindow->RootWindow == window && IsMousePosValid())
     {
-        window->Viewport = AddUpdateViewport(window, window->ID, window->Pos, window->Size, ImGuiViewportFlags_NoDecoration | ImGuiViewportFlags_NoFocusOnAppearing | ImGuiViewportFlags_NoInputs);
+        if (!window->Viewport->GetRect().Contains(window->Rect()))
+            window->Viewport = AddUpdateViewport(window, window->ID, window->Pos, window->Size, ImGuiViewportFlags_NoDecoration | ImGuiViewportFlags_NoFocusOnAppearing | ImGuiViewportFlags_NoInputs);
     }
     else if (!window->ViewportOwned && GetWindowAlwaysWantOwnViewport(window))
     {