File x3270-handle-missing-font.patch of Package x3270.18298

--- x3270/screen.c	2020-10-30 13:35:58.238416347 +0100
+++ x3270/screen.c	2020-10-30 13:39:12.721353850 +0100
@@ -4686,7 +4686,9 @@
 	}
     }
 
-    g = XLoadQueryFont(display, best);
+    if ((g = XLoadQueryFont(display, best)) == NULL) {
+        return xs_buffer("Font %s could not be loaded", best);
+    }
     set_font_globals(g, /*name*/best, best, g->fid, is_dbcs);
     return NULL;
 }