Quick Asterisk 1.8 patch to allow a blank caller-id

This patch is for users who are trying to connect Asterisk to a trunk or gateway that doesn’t allow a caller-id. Normally when you set it blank, it will fill in “asterisk” as the ID.

Some providers or devices don’t allow a user in the From: field at all. In those cases, you will need a quick little patch to allow it to be blank. If a caller-id is specified on the channel, it will get passed through.

--- channels/sip/include/sip.h  2013-01-09 16:30:25.000000000 -0400
+++ channels/sip/include/sip.h  2013-06-26 13:52:03.713476705 -0300
@@ -184,7 +184,7 @@
 #define DEFAULT_MOHINTERPRET   "default"  /*!< The default music class */
 #define DEFAULT_MOHSUGGEST     ""
 #define DEFAULT_VMEXTEN        "asterisk" /*!< Default voicemail extension */
-#define DEFAULT_CALLERID       "asterisk" /*!< Default caller ID */
+#define DEFAULT_CALLERID       "" /*!< Default caller ID */
 #define DEFAULT_MWI_FROM       ""
 #define DEFAULT_NOTIFYMIME     "application/simple-message-summary"
 #define DEFAULT_ALLOWGUEST     TRUE
--- channels/chan_sip.c 2013-06-26 13:45:36.202153235 -0300
+++ channels/chan_sip.c 2013-06-26 13:44:47.912153728 -0300
@@ -12495,9 +12495,9 @@

        ourport = (p->fromdomainport) ? p->fromdomainport : ast_sockaddr_port(&p->ourip);
        if (!sip_standard_port(p->socket.type, ourport)) {
-               snprintf(from, sizeof(from), ""%s" <sip:%s@%s:%d>;tag=%s", n, tmp_l, d, ourport, p->tag);
+               snprintf(from, sizeof(from), ""%s" <sip:%s%s%s:%d>;tag=%s", n, tmp_l, ast_strlen_zero(tmp_l) ? "" : "@", d, ourport, p->tag);
        } else {
-               snprintf(from, sizeof(from), ""%s" <sip:%s@%s>;tag=%s", n, tmp_l, d, p->tag);
+               snprintf(from, sizeof(from), ""%s" <sip:%s%s%s>;tag=%s", n, tmp_l, ast_strlen_zero(tmp_l) ? "" : "@", d, p->tag);
        }

        if (!ast_strlen_zero(explicit_uri)) {