diff -ruNp libtool-1.5~/ChangeLog libtool-1.5/ChangeLog
--- libtool-1.5~/ChangeLog	2003-04-14 23:48:00.000000000 +0100
+++ libtool-1.5/ChangeLog	2003-09-10 22:53:55.000000000 +0100
@@ -0,0 +1,6 @@
+2003-10-09  Scott James Remnant  <address@hidden>
+
+	* libltdl/ltdl.c (lt_dlerror): change return value when
+	no error has occured to NULL to match documentation.
+	(Debian Bug #157229)
+
diff -ruNp libtool-1.5~/libltdl/ltdl.c libtool-1.5/libltdl/ltdl.c
--- libtool-1.5~/libltdl/ltdl.c	2003-03-29 04:09:00.000000000 +0000
+++ libtool-1.5/libltdl/ltdl.c	2003-09-10 22:52:54.000000000 +0100
@@ -3919,7 +3919,7 @@ lt_dlerror ()
   LT_DLMUTEX_GETERROR (error);
   LT_DLMUTEX_SETERROR (0);
 
-  return error ? error : LT_DLSTRERROR (UNKNOWN);
+  return error ? error : NULL;
 }
 
 static int