Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 341249)
+++ channels/chan_sip.c	(working copy)
@@ -14605,10 +14605,21 @@
 	SIP_PEDANTIC_DECODE(name);
 	SIP_PEDANTIC_DECODE(domain);
 
-	/*! \todo XXX here too we interpret a missing @domain as a name-only
-	 * URI, whereas the RFC says this is a domain-only uri.
-	 */
-	if (!ast_strlen_zero(domain) && !AST_LIST_EMPTY(&domain_list)) {
+	if (ast_strlen_zero(domain)) {
+		/* <sip:name@[EMPTY]>, not good */
+		transmit_response(p, "404 Not found", &p->initreq);
+		return AUTH_UNKNOWN_DOMAIN;
+	}
+
+	if (ast_strlen_zero(name)) {
+		/* <sip:[EMPTY]domain>, not valid for registration:
+		 * RFC3261, 10.2: The To header field and the Request-URI field
+		 * typically differ, as the former contains a user name. */
+		transmit_response(p, "404 Not found", &p->initreq);
+		return AUTH_NOT_FOUND;
+	}
+
+	if (!AST_LIST_EMPTY(&domain_list)) {
 		if (!check_sip_domain(domain, NULL, 0)) {
 			transmit_response(p, "404 Not found (unknown domain)", &p->initreq);
 			return AUTH_UNKNOWN_DOMAIN;
@@ -15997,15 +16008,7 @@
 	SIP_PEDANTIC_DECODE(of);
 	SIP_PEDANTIC_DECODE(domain);
 
-	if (ast_strlen_zero(of)) {
-		/* XXX note: the original code considered a missing @host
-		 * as a username-only URI. The SIP RFC (19.1.1) says that
-		 * this is wrong, and it should be considered as a domain-only URI.
-		 * For backward compatibility, we keep this block, but it is
-		 * really a mistake and should go away.
-		 */
-		of = domain;
-	} else {
+	if (!ast_strlen_zero(of)) {
 		char *tmp = ast_strdupa(of);
 		/* We need to be able to handle auth-headers looking like
 			<sip:8164444422;phone-context=+1@1.2.3.4:5060;user=phone;tag=SDadkoa01-gK0c3bdb43>
@@ -16077,21 +16080,21 @@
 static int get_msg_text(char *buf, int len, struct sip_request *req, int addnewline)
 {
 	int x;
-	int y;
+	int linelen;
 
 	buf[0] = '\0';
-	/*XXX isn't strlen(buf) going to always be 0? */
-	y = len - strlen(buf) - 5;
-	if (y < 0)
-		y = 0;
-	for (x = 0; x < req->lines; x++) {
+	--len; /* reserve strncat null */
+	for (x = 0; len > 0 && x < req->lines; x++) {
 		const char *line = REQ_OFFSET_TO_STR(req, line[x]);
-		strncat(buf, line, y); /* safe */
-		y -= strlen(line) + 1;
-		if (y < 0)
-			y = 0;
-		if (y != 0 && addnewline)
+		strncat(buf, line, len); /* safe */
+		linelen = strlen(buf);
+		buf += linelen;
+		len -= linelen;
+		if (len && addnewline) {
 			strcat(buf, "\n"); /* safe */
+			++buf;
+			--len;
+		}
 	}
 	return 0;
 }
Index: channels/sip/reqresp_parser.c
===================================================================
--- channels/sip/reqresp_parser.c	(revision 341249)
+++ channels/sip/reqresp_parser.c	(working copy)
@@ -176,23 +176,23 @@
 			}
 
 			if (!strcmp(label, "transport")) {
-				if (params) {params->transport=value;}
+				params->transport = value;
 				rem = parameters;
 			} else if (!strcmp(label, "user")) {
-				if (params) {params->user=value;}
+				params->user = value;
 				rem = parameters;
 			} else if (!strcmp(label, "method")) {
-				if (params) {params->method=value;}
+				params->method = value;
 				rem = parameters;
 			} else if (!strcmp(label, "ttl")) {
-				if (params) {params->ttl=value;}
+				params->ttl = value;
 				rem = parameters;
 			} else if (!strcmp(label, "maddr")) {
-				if (params) {params->maddr=value;}
+				params->maddr = value;
 				rem = parameters;
 			/* Treat "lr", "lr=yes", "lr=on", "lr=1", "lr=almostanything" as lr enabled and "", "lr=no", "lr=off", "lr=0", "lr=" and "lranything" as lr disabled */
 			} else if ((!strcmp(label, "lr") && strcmp(value, "no") && strcmp(value, "off") && strcmp(value, "0") && strcmp(value, "")) || ((lr) && strcmp(value, "lr"))) {
-				if (params) {params->lr=1;}
+				params->lr = 1;
 				rem = parameters;
 			} else {
 				value--;