Docking: make dock node tab bar ID match parent ID of its tab items.

imgui.cpp

diff --git a/imgui.cpp b/imgui.cpp
index f3ad085..eebffff 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -19406,7 +19406,7 @@
     tab_bar_flags |= ImGuiTabBarFlags_DrawSelectedOverline;
     if (!host_window->Collapsed && is_focused)
         tab_bar_flags |= ImGuiTabBarFlags_IsFocused;
-    tab_bar->ID = GetID("#TabBar");
+    tab_bar->ID = node->ID;// GetID("#TabBar");
     tab_bar->SeparatorMinX = node->Pos.x + host_window->WindowBorderSize; // Separator cover the whole node width
     tab_bar->SeparatorMaxX = node->Pos.x + node->Size.x - host_window->WindowBorderSize;
     BeginTabBarEx(tab_bar, tab_bar_rect, tab_bar_flags);

imgui_widgets.cpp

diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 93589a1..57ab6f0 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -9659,7 +9659,7 @@
         return false;
 
     IM_ASSERT(tab_bar->ID != 0);
-    if ((flags & ImGuiTabBarFlags_DockNode) == 0)
+    if ((flags & ImGuiTabBarFlags_DockNode) == 0) // Already done
         PushOverrideID(tab_bar->ID);
 
     // Add to stack
@@ -9742,7 +9742,7 @@
         window->DC.CursorPos = tab_bar->BackupCursorPos;
 
     tab_bar->LastTabItemIdx = -1;
-    if ((tab_bar->Flags & ImGuiTabBarFlags_DockNode) == 0)
+    if ((tab_bar->Flags & ImGuiTabBarFlags_DockNode) == 0) // Already done
         PopID();
 
     g.CurrentTabBarStack.pop_back();