From 503b8c20de28373f8d6c6e5837983833fc9ae234 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Thu, 2 Apr 2015 17:48:22 +0100
Subject: [PATCH] Delete font clear pointer in ImGui state to get a clear
 crasah instead of a dangling pointer. #181

---
 imgui.cpp | 10 ++++++++++
 imgui.h   |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/imgui.cpp b/imgui.cpp
index 51ee2e66..6f87da2b 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -8264,6 +8264,16 @@ ImFont::ImFont()
     Clear();
 }
 
+ImFont::~ImFont()
+{
+    // Invalidate active font so that the user gets a clear crash instead of a dangling pointer.
+    // If you want to delete fonts you need to do it between Render() and NewFrame().
+    ImGuiState& g = *GImGui;
+    if (g.Font == this)
+        g.Font = NULL;
+    Clear();
+}
+
 void    ImFont::Clear()
 {
     FontSize = 0.0f;
diff --git a/imgui.h b/imgui.h
index d237e09e..8035090e 100644
--- a/imgui.h
+++ b/imgui.h
@@ -998,7 +998,7 @@ struct ImFont
 
     // Methods
     IMGUI_API ImFont();
-    IMGUI_API ~ImFont() { Clear(); }
+    IMGUI_API ~ImFont();
     IMGUI_API void                  Clear();
     IMGUI_API void                  BuildLookupTable();
     IMGUI_API const Glyph*          FindGlyph(unsigned short c) const;