--- src/diff3.c	2004-04-12 09:44:35.000000000 +0200
+++ src/diff3.c.oden	2008-12-19 16:30:54.000000000 +0100
@@ -1406,7 +1406,7 @@ output_diff3 (FILE *outputfile, struct d
 	      line = 0;
 	      do
 		{
-		  fprintf (outputfile, line_prefix);
+		  fprintf (outputfile, "%s", line_prefix);
 		  cp = D_RELNUM (ptr, realfile, line);
 		  length = D_RELLEN (ptr, realfile, line);
 		  fwrite (cp, sizeof (char), length, outputfile);