openbsd writes a warning to the kernel log when you sprintf a null pointer

Index: third-party/pjproject/source/pjmedia/src/pjmedia/sdp.c
--- third-party/pjproject/source/pjmedia/src/pjmedia/sdp.c.orig
+++ third-party/pjproject/source/pjmedia/src/pjmedia/sdp.c
@@ -597,13 +597,13 @@ PJ_DEF(pj_status_t) pjmedia_sdp_rtpmap_to_attr(pj_pool
     len = pj_ansi_snprintf(tempbuf, sizeof(tempbuf), 
 			   "%.*s %.*s/%u%s%.*s",
 			   (int)rtpmap->pt.slen,
-			   rtpmap->pt.ptr,
+			   rtpmap->pt.ptr ? rtpmap->pt.ptr : "(null)",
 			   (int)rtpmap->enc_name.slen,
-			   rtpmap->enc_name.ptr,
+			   rtpmap->enc_name.ptr ? rtpmap->enc_name.ptr : "(null)",
 			   rtpmap->clock_rate,
 			   (rtpmap->param.slen ? "/" : ""),
 			   (int)rtpmap->param.slen,
-			   rtpmap->param.ptr);
+			   rtpmap->param.ptr ? rtpmap->param.ptr : "(null)");
 
     if (len < 1 || len >= (int)sizeof(tempbuf))
 	return PJMEDIA_SDP_ERTPMAPTOOLONG;
