[gtk/wip/chergert/glproto: 310/526] unlikely but check anyway

[Christian Hergert <chergert src gnome org>]

commit c1ee0aaa5da65629bf4a554c11bcd8b49b86fceb
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jan 26 13:49:11 2021 -0800

    unlikely but check anyway

 gsk/next/gskglrenderjob.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gsk/next/gskglrenderjob.c b/gsk/next/gskglrenderjob.c
index 90e820114b..b288a5542e 100644
--- a/gsk/next/gskglrenderjob.c
+++ b/gsk/next/gskglrenderjob.c
@@ -2553,6 +2553,9 @@ gsk_gl_render_job_visit_text_node (GskGLRenderJob *job,
   GskGLGlyphKey lookup;
   guint last_texture = 0;
 
+  if (num_glyphs == 0)
+    return;
+
   /* If the font has color glyphs, we don't need to recolor anything */
   if (!force_color && gsk_text_node_has_color_glyphs (node))
     {