TabBars in Tab can cause crash

[cmheo]

Version/Branch of Dear ImGui:

Version: 1.69 WIP (16899)
Branch: master

Back-end/Renderer/Compiler/OS

Back-ends: imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp

if (show_crash_window)
{
	char buf[2048] = { 0 };

	ImGui::Begin("TabBar Crash", &show_crash_window);

	ImGuiTabBarFlags tab_bar_flags = ImGuiTabBarFlags_None;
	if (ImGui::BeginTabBar("TabBar 0", tab_bar_flags))
	{
		if (ImGui::BeginTabItem("TabItem 0 in TabBar 0"))
		{
			ImGui::Text("TabItem 0 in TabBar 0");

			// if we have many tab bars here, it will invalidate pointers in g.CurrentTabBar
			for (int i = 0; i < 128; i++)
			{
				sprintf(buf, "Inner TabBar %d", i);
				if (ImGui::BeginTabBar(buf, tab_bar_flags))
				{
					sprintf(buf, "Inner TabBar %d TabItem", i);
					if (ImGui::BeginTabItem(buf))
					{
						ImGui::Text("Inner TabBar TabItem");
						ImGui::EndTabItem();
					}

					ImGui::EndTabBar();
				}
			}

			ImGui::Text("TabBar 0 pointer in g.CurrentTabar is invalid");
			ImGui::EndTabItem();
		}

		ImGui::EndTabBar();
	}

	ImGui::End();
}

[ocornut]

Confirmed the bug, thank you. It's a really silly error on my side to have let that go (the stack stores tabbar pointers that are pointing to a resizable vector). Fixing soon.

[ocornut]

I have pushed a fix for this, confirmed with docking branch and added a test for recursive manual tab bar in my wip testing system. Thanks again!

[cmheo]

Thank you! I will pull the fix. Thanks again.