From 1848480798463e1757bf714fdbcc5de0edf370d7 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Mon, 19 Oct 2020 14:06:14 +0200
Subject: [PATCH] Begin: WIP consistent Begin/End behavior, more fixes.

---
 imgui.cpp         | 27 ++++++++++++++-------------
 imgui_demo.cpp    | 15 +++++++--------
 imgui_widgets.cpp |  2 +-
 3 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/imgui.cpp b/imgui.cpp
index a818748b..1ffd0e5b 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -4115,7 +4115,9 @@ void ImGui::NewFrame()
     // - The fallback window exceptionally doesn't call End() automatically if Begin() returns false (this is intended).
     g.WithinFrameScopeWithImplicitWindow = true;
     SetNextWindowSize(ImVec2(400, 400), ImGuiCond_FirstUseEver);
-    Begin("Debug##Default");
+    bool ret = Begin("Debug##Default");
+    IM_UNUSED(ret);
+    IM_ASSERT(ret);
     IM_ASSERT(g.CurrentWindow->IsFallbackWindow == true);
 
     // [DEBUG] When io.ConfigDebugBeginReturnValue is set, we make Begin() return false at different level of the window stack to validate Begin()/End() behavior in user code.
@@ -5215,7 +5217,6 @@ void ImGui::EndChild()
 // Helper to create a child window / scrolling region that looks like a normal widget frame.
 bool ImGui::BeginChildFrame(ImGuiID id, const ImVec2& size, ImGuiWindowFlags extra_flags)
 {
-    // FIXME-NEWBEGIN
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
     PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
@@ -6760,22 +6761,22 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
     }
 
     // FIXME-OPT
-    if (window->SkipItems || g.DebugBeginReturnValueCullDepth == g.CurrentWindowStack.Size)
+    bool debug_skip = (g.DebugBeginReturnValueCullDepth == g.CurrentWindowStack.Size) && (window->Flags & ImGuiWindowFlags_DockNodeHost) == 0;
+    if (window->SkipItems || debug_skip)
     {
         // The implicit fallback is NOT automatically ended as an exception to the rule,
         // allowing it to always be able to receive commands without crashing.
-        if (!window->IsFallbackWindow)
-        {
-            if (window->Flags & ImGuiWindowFlags_Popup)
-                EndPopup();
-            else if (window->Flags & ImGuiWindowFlags_ChildWindow)
-                EndChild();
-            else
-                End();
-        }
+        if (window->IsFallbackWindow)
+            return true;
+
+        if (window->Flags & ImGuiWindowFlags_Popup)
+            EndPopup();
+        else if (window->Flags & ImGuiWindowFlags_ChildWindow)
+            EndChild();
+        else
+            End();
         return false;
     }
-
     return true;
 }
 
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 76b8c957..535150a5 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -5422,15 +5422,13 @@ void ImGui::ShowAboutWindow(bool* p_open)
 
     static bool show_config_info = false;
     ImGui::Checkbox("Config/Build Information", &show_config_info);
-    if (show_config_info)
+
+    ImGuiIO& io = ImGui::GetIO();
+    ImGuiStyle& style = ImGui::GetStyle();
+    const bool copy_to_clipboard = show_config_info && ImGui::Button("Copy to clipboard");
+    const ImVec2 child_size = ImVec2(0, ImGui::GetTextLineHeightWithSpacing() * 18);
+    if (show_config_info && ImGui::BeginChildFrame(ImGui::GetID("cfg_infos"), child_size, ImGuiWindowFlags_NoMove))
     {
-        ImGuiIO& io = ImGui::GetIO();
-        ImGuiStyle& style = ImGui::GetStyle();
-
-        bool copy_to_clipboard = ImGui::Button("Copy to clipboard");
-        ImVec2 child_size = ImVec2(0, ImGui::GetTextLineHeightWithSpacing() * 18);
-        ImGui::BeginChildFrame(ImGui::GetID("cfg_infos"), child_size, ImGuiWindowFlags_NoMove);
-
         if (copy_to_clipboard)
         {
             ImGui::LogToClipboard();
@@ -5558,6 +5556,7 @@ void ImGui::ShowAboutWindow(bool* p_open)
             ImGui::LogText("\n```\n");
             ImGui::LogFinish();
         }
+        ImGui::EndChildFrame();
     }
     ImGui::End();
 }
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index 2e99e6ed..e9ce7489 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -6131,7 +6131,7 @@ bool ImGui::ListBoxHeader(const char* label, const ImVec2& size_arg)
     if (label_size.x > 0)
         RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label);
 
-    // FIXME-NEWBEGIN
+    // FIXME-NEWBEGIN: Use to be return true so we'll trigger more issues.
     return BeginChildFrame(id, frame_bb.GetSize());
 }