From 670775ac22e4fb93be2335d9c4ceb50f5f9ab056 Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Thu, 13 Apr 2017 20:01:24 +0200
Subject: [PATCH] Added assert/comment about using MergeMode (#1100)

---
 imgui_draw.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 1b2e9e0c..b0931b60 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -1143,6 +1143,10 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
         IM_PLACEMENT_NEW(font) ImFont();
         Fonts.push_back(font);
     }
+    else
+    {
+        IM_ASSERT(!Fonts.empty()); // When using MergeMode make sure that a font has already been added before. You can use ImGui::AddFontDefault() to add the default imgui font.
+    }
 
     ConfigData.push_back(*font_cfg);
     ImFontConfig& new_font_cfg = ConfigData.back();