Docking: follow to 27c735e to fix rendering of docked-window scrollba…

…r above outer border. (#2522)

docs/CHANGELOG.txt

@@ -131,6 +131,7 @@ Docking+Viewports Branch:
 
 - Docking: added style.DockingSeparatorSize, ImGuiStyleVar_DockingSeparatorSize. Now
   also scaled by style.ScaleAllSizes(). (#3481, #4721, #2522) [@PossiblyAShrub, @wobbier]
+- Docking: fixed rendering of docked-window scrollbar above outer border. (#2522)
 
 
 -----------------------------------------------------------------------

imgui.cpp

@@ -6860,7 +6860,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // LOCK BORDER SIZE AND PADDING FOR THE FRAME (so that altering them doesn't cause inconsistencies)
         // We read Style data after the call to UpdateSelectWindowViewport() which might be swapping the style.
 
-        if (flags & ImGuiWindowFlags_ChildWindow)
+        if (!window->DockIsActive && (flags & ImGuiWindowFlags_ChildWindow))
             window->WindowBorderSize = style.ChildBorderSize;
         else
             window->WindowBorderSize = ((flags & (ImGuiWindowFlags_Popup | ImGuiWindowFlags_Tooltip)) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;