gentoo-overlay/app-text/llpp/files/llpp-20-WM_CLASS.patch

--- llpp-20/link.c
+++ llpp-20/link.c
@@ -4305,6 +4305,32 @@
 }
 #endif
 
+#if !defined (_WIN32) && !defined (__APPLE__)
+#undef pixel
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <GL/glx.h>
+
+static void set_wm_class (void)
+{
+    Display *dpy;
+    Window win;
+    int screen;
+    XClassHint hint;
+
+    dpy = XOpenDisplay (getenv ("DISPLAY"));
+    screen = DefaultScreen (dpy);
+    hint.res_name = "llpp";
+    hint.res_class = "llpp";
+    win = glXGetCurrentDrawable ();
+    XSetClassHint (dpy, win, &hint);
+    XCloseDisplay (dpy);
+}
+#else
+#define set_wm_class()
+#endif
+
 CAMLprim value ml_init (value csock_v, value params_v)
 {
     CAMLparam2 (csock_v, params_v);
@@ -4425,5 +4451,6 @@
         errx (1, "pthread_create: %s", strerror (ret));
     }
 
+    set_wm_class ();
     CAMLreturn (Val_unit);
 }