add more paranoid handling to pbx_builtin_serialize_variables

git-svn-id: http://svn.digium.com/svn/asterisk/trunk@4107 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 8 insertions, 5 deletions

diff --git a/pbx.c b/pbx.c
index e40746d93..c6d7e3f1e 100755
--- a/pbx.c
+++ b/pbx.c
@@ -4921,18 +4921,21 @@ int pbx_builtin_serialize_variables(struct ast_channel *chan, char *buf, size_t
 {
 	struct ast_var_t *variables;
 	struct varshead *headp;
+	char *var=NULL ,*val=NULL;
 	int total = 0;
 
 	memset(buf,0,size);
 	if (chan) {
 		headp=&chan->varshead;
 		AST_LIST_TRAVERSE(headp,variables,entries) {
-			snprintf(buf + strlen(buf), size - strlen(buf), "%s=%s\n", ast_var_name(variables), ast_var_value(variables));
-			if(strlen(buf) >= size) {
-				ast_log(LOG_ERROR,"Data Buffer Size Exceeded!\n");
-				break;
+			if(chan && variables && (var=ast_var_name(variables)) && (val=ast_var_value(variables))) {
+				snprintf(buf + strlen(buf), size - strlen(buf), "%s=%s\n", var, val);
+				if(strlen(buf) >= size) {
+					ast_log(LOG_ERROR,"Data Buffer Size Exceeded!\n");
+					break;
+				}
+				total++;
 			}
-			total++;
 		}
 	}