Pretty up a debug message if the referred-by-uri isn't available

Instead of formatting a NULL pointer into a "%s" format string (which is
usually not a good thing to do), we instead print "Unknown".

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@394278 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 3c1f97b..83c521d 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -18141,7 +18141,7 @@ static int get_refer_info(struct sip_pvt *transferer, struct sip_request *outgoi
        /* Either an existing extension or the parking extension */
        if (refer->attendedtransfer || ast_exists_extension(NULL, transfer_context, refer_to, 1, NULL)) {
                if (sip_debug_test_pvt(transferer)) {
-                       ast_verbose("SIP transfer to extension %s@%s by %s\n", refer_to, transfer_context, referred_by_uri);
+                       ast_verbose("SIP transfer to extension %s@%s by %s\n", refer_to, transfer_context, S_OR(referred_by_uri, "Unknown"));
                }
                /* We are ready to transfer to the extension */
                return 0;