diff -up openslp-1.2.1/slpd/slpd_log.c.orig openslp-1.2.1/slpd/slpd_log.c
--- openslp-1.2.1/slpd/slpd_log.c.orig	2005-02-08 05:34:31.000000000 +0000
+++ openslp-1.2.1/slpd/slpd_log.c	2009-09-15 19:39:23.000000000 +0100
@@ -179,7 +179,8 @@ void SLPDLogBuffer(const char* prefix, i
     if (G_SlpdLogFile)
     {
         fprintf(G_SlpdLogFile,"%s",prefix);
-        fwrite(buf,bufsize,1,G_SlpdLogFile);
+        if (buf && (bufsize > 0))
+            fwrite(buf,bufsize,1,G_SlpdLogFile);
         fprintf(G_SlpdLogFile,"\n");
         fflush(G_SlpdLogFile);
     }
@@ -275,7 +276,21 @@ void SLPDLogSrvTypeRqstMessage(SLPSrvTyp
 /*-------------------------------------------------------------------------*/
 {
     SLPDLog("Message SRVTYPERQST:\n");
-    SLPDLogBuffer("   namingauth = ", srvtyperqst->namingauthlen, srvtyperqst->namingauth);
+
+    if (srvtyperqst->namingauthlen == 0xffff)
+    {
+        /* Naming authority matches all */
+        SLPDLog("   namingauth = (all)\n");
+    }
+    else if (srvtyperqst->namingauthlen == 0)
+    {
+        SLPDLog("   namingauth = (empty)\n");
+    }
+    else
+    {
+        /* Naming authority has been provided */
+        SLPDLogBuffer("   namingauth = ", srvtyperqst->namingauthlen, srvtyperqst->namingauth);
+    }
     SLPDLogBuffer("   scope = ", srvtyperqst->scopelistlen, srvtyperqst->scopelist);
 }