snmp plugin: Fix an off by one error.

The last character of an table instance was truncated. Fortunately empty
strings were caught, so that uninitialized memory was never accessed.

This patch also reverts f782b378: If returning with an error when a string
is empty causes the entire read to fail.

diff --git a/src/snmp.c b/src/snmp.c
index 0dad67c8b727232cc0072bd68eb77d7fbd8a5002..877aafe92b2bf959f8604916776020460b847ea2 100644 (file)
--- a/src/snmp.c
+++ b/src/snmp.c
@@ -859,22 +859,15 @@ static int csnmp_instance_list_add (csnmp_list_instances_t **head,
     char *ptr;
     size_t instance_len;
 
+    memset (il->instance, 0, sizeof (il->instance));
     instance_len = sizeof (il->instance) - 1;
     if (instance_len > vb->val_len)
       instance_len = vb->val_len;
 
-    if (instance_len < 1)
-    {
-      ERROR ("snmp plugin: csnmp_instance_list_add: instance_len = %zu, "
-         "which is less than one.", instance_len);
-      sfree (il);
-      return (-1);
-    }
-
     sstrncpy (il->instance, (char *) ((vb->type == ASN_OCTET_STR)
          ? vb->val.string
          : vb->val.bitstring),
-       instance_len);
+       instance_len + 1);
 
     for (ptr = il->instance; *ptr != '\0'; ptr++)
     {