Better error handling for glGetString(GL_VERSION)

Author: cschreib

impl/gui/gl/src/gui_gl_renderer.cpp

@@ -53,7 +53,12 @@ renderer::renderer(const vector2ui& window_dimensions, bool init_glew [[maybe_un
 }
 
 std::string renderer::get_name() const {
-    std::string full_version = reinterpret_cast<const char*>(glGetString(GL_VERSION));
+    const char* gl_version = reinterpret_cast<const char*>(glGetString(GL_VERSION));
+    if (gl_version == nullptr) {
+        throw gui::exception("Cannot get OpenGL version; check that an OpenGL context exists");
+    }
+
+    std::string full_version = gl_version;
 #if defined(LXGUI_OPENGL3)
 #    if defined(LXGUI_COMPILER_EMSCRIPTEN)
     return "WebGL (" + full_version + ")";