Docking: Fixed moving window being interrupted when undocing a window with "io.ConfigDockingAlwaysTabBar = true". (#5324)

Regression introduced in 6b7766817

docs/CHANGELOG.txt

@@ -188,7 +188,9 @@ Other Changes:
 Docking+Viewports Branch:
 
 - Docking: Fixed floating docked nodes not being clamped into viewport workrect to stay reachable
-  when g.ConfigWindowsMoveFromTitleBarOnly is set and multi-viewports are disabled. (#5044)
+  when io.ConfigWindowsMoveFromTitleBarOnly is true and multi-viewports are disabled. (#5044)
+- Docking: Fixed a regression where moving window would be interrupted after undocking a tab
+  when io.ConfigDockingAlwaysTabBar is true. (#5324) [@rokups]
 - Viewports: Fixed translating a host viewport from briefly altering the size of AlwaysAutoResize windows. (#5057)
 - Viewports: Fixed main viewport size not matching ImDrawData::DisplaySize for one frame during resize
   when multi-viewports are disabled. (#4900)

imgui.cpp

@@ -3936,7 +3936,7 @@ void ImGui::UpdateMouseMovingWindowNewFrame()
         ImGuiWindow* moving_window = g.MovingWindow->RootWindowDockTree;
 
         // When a window stop being submitted while being dragged, it may will its viewport until next Begin()
-        const bool window_disappared = (!moving_window->WasActive || moving_window->Viewport == NULL);
+        const bool window_disappared = ((!moving_window->WasActive && !moving_window->Active) || moving_window->Viewport == NULL);
         if (g.IO.MouseDown[0] && IsMousePosValid(&g.IO.MousePos) && !window_disappared)
         {
             ImVec2 pos = g.IO.MousePos - g.ActiveIdClickOffset;