From 937f6112ce64255db980c0b1df9818d0a52a4a33 Mon Sep 17 00:00:00 2001
From: Vojtech Kral <vojtech@kral.hk>
Date: Tue, 26 Mar 2019 17:57:54 +0100
Subject: [PATCH] imgui: Fix assert caused by set_language() while new frame is
 open

---
 src/slic3r/GUI/ImGuiWrapper.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/slic3r/GUI/ImGuiWrapper.cpp b/src/slic3r/GUI/ImGuiWrapper.cpp
index 0050b6463..0932c8ce9 100644
--- a/src/slic3r/GUI/ImGuiWrapper.cpp
+++ b/src/slic3r/GUI/ImGuiWrapper.cpp
@@ -56,6 +56,14 @@ bool ImGuiWrapper::init()
 
 void ImGuiWrapper::set_language(const std::string &language)
 {
+    if (m_new_frame_open) {
+        // ImGUI internally locks the font between NewFrame() and EndFrame()
+        // NewFrame() might've been called here because of input from the 3D scene;
+        // call EndFrame()
+        ImGui::EndFrame();
+        m_new_frame_open = false;
+    }
+
     const ImWchar *ranges = nullptr;
     size_t idx = language.find('_');
     std::string lang = (idx == std::string::npos) ? language : language.substr(0, idx);