don't set the account code if one wasn't supplied (bug #4751)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/v1-0@6219 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_disa.c

@@ -22,6 +22,7 @@
 #include <asterisk/module.h>
 #include <asterisk/translate.h>
 #include <asterisk/ulaw.h>
+#include <asterisk/utils.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -312,7 +313,8 @@ static int disa_exec(struct ast_channel *chan, void *data)
 		}
 		strncpy(chan->exten, exten, sizeof(chan->exten) - 1);
 		strncpy(chan->context, ourcontext, sizeof(chan->context) - 1);
-		strncpy(chan->accountcode, acctcode, sizeof(chan->accountcode) - 1);
+		if (!ast_strlen_zero(acctcode))
+			strncpy(chan->accountcode, acctcode, sizeof(chan->accountcode) - 1);
 		chan->priority = 0;
 		ast_cdr_init(chan->cdr,chan);
 		LOCAL_USER_REMOVE(u);