diff --git a/imgui.cpp b/imgui.cpp
index 7db3d6e0..e6cb324c 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5143,6 +5143,7 @@ ImGuiWindow* ImGui::FindWindowByName(const char* name)
 static ImGuiWindow* CreateNewWindow(const char* name, ImVec2 size, ImGuiWindowFlags flags)
 {
     ImGuiContext& g = *GImGui;
+    //IMGUI_DEBUG_LOG("CreateNewWindow '%s', flags = 0x%08X\n", name, flags);
 
     // Create window the first time
     ImGuiWindow* window = IM_NEW(ImGuiWindow)(&g, name);
@@ -14571,7 +14572,12 @@ void ImGui::ShowMetricsWindow(bool* p_open)
 
         static void NodeWindow(ImGuiWindow* window, const char* label)
         {
-            if (!ImGui::TreeNode(window, "%s '%s', %d @ 0x%p", label, window->Name, window->Active || window->WasActive, window))
+            if (window == NULL)
+            {
+                ImGui::BulletText("%s: NULL", label);
+                return;
+            }
+            if (!ImGui::TreeNode(window, "%s '%s', %d @ 0x%p", label, window->Name, (window->Active || window->WasActive), window))
                 return;
             ImGuiWindowFlags flags = window->Flags;
             NodeDrawList(window, window->Viewport, window->DrawList, "DrawList");
diff --git a/imgui_internal.h b/imgui_internal.h
index be6a0ca7..ddad75f4 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -148,12 +148,15 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #define IM_NEWLINE      "\n"
 #endif
 #define IM_TABSIZE      (4)
-
-#define IMGUI_DEBUG_LOG(_FMT,...)       printf("[%05d] " _FMT, GImGui->FrameCount, __VA_ARGS__)
 #define IM_STATIC_ASSERT(_COND)         typedef char static_assertion_##__line__[(_COND)?1:-1]
 #define IM_F32_TO_INT8_UNBOUND(_VAL)    ((int)((_VAL) * 255.0f + ((_VAL)>=0 ? 0.5f : -0.5f)))   // Unsaturated, for display purpose
 #define IM_F32_TO_INT8_SAT(_VAL)        ((int)(ImSaturate(_VAL) * 255.0f + 0.5f))               // Saturated, always output 0..255
 
+// Debug Logging
+#ifndef IMGUI_DEBUG_LOG
+#define IMGUI_DEBUG_LOG(_FMT,...)       printf("[%05d] " _FMT, GImGui->FrameCount, __VA_ARGS__)
+#endif
+
 // Enforce cdecl calling convention for functions called by the standard library, in case compilation settings changed the default to e.g. __vectorcall
 #ifdef _MSC_VER
 #define IMGUI_CDECL __cdecl
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 4d9e9942..91033993 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -5947,6 +5947,10 @@ void ImGui::EndMainMenuBar()
     End();
 }
 
+// FIXME: Provided a rectangle perhaps e.g. a BeginMenuBarEx() could be used anywhere..
+// Currently the main responsibility of this function being to setup clip-rect + horizontal layout + menu navigation layer.
+// Ideally we also want this to be responsible for claiming space out of the main window scrolling rectangle, in which case ImGuiWindowFlags_MenuBar will become unnecessary.
+// Then later the same system could be used for multiple menu-bars, scrollbars, side-bars.
 bool ImGui::BeginMenuBar()
 {
     ImGuiWindow* window = GetCurrentWindow();
@@ -5956,7 +5960,7 @@ bool ImGui::BeginMenuBar()
         return false;
 
     IM_ASSERT(!window->DC.MenuBarAppending);
-    BeginGroup(); // Backup position on layer 0
+    BeginGroup(); // Backup position on layer 0 // FIXME: Misleading to use a group for that backup/restore
     PushID("##menubar");
 
     // We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.