[snmp/agent] Local DB counter increment wrap error

The counter increment function in the local-db was incorrect.
It did not handle counter wrap correctly.

OTP-11192

2 files changed, 21 insertions, 1 deletions

diff --git a/lib/snmp/src/agent/snmpa_local_db.erl b/lib/snmp/src/agent/snmpa_local_db.erl
index 2c0cad807a..5198c6ec4e 100644
--- a/lib/snmp/src/agent/snmpa_local_db.erl
+++ b/lib/snmp/src/agent/snmpa_local_db.erl
@@ -583,7 +583,7 @@ handle_cast({variable_inc, Name, Db, N}, State) ->
 	    {value, Val} -> Val;
 	    _ -> 0 
 	end,
-    insert(Db, Name, M+N rem 4294967296, State),
+    insert(Db, Name, (M+N) rem 4294967296, State),
     {noreply, State};
     
 handle_cast({verbosity,Verbosity}, State) ->
diff --git a/lib/snmp/src/app/snmp.appup.src b/lib/snmp/src/app/snmp.appup.src
index 7ffa4a725d..53de57efd3 100644
--- a/lib/snmp/src/app/snmp.appup.src
+++ b/lib/snmp/src/app/snmp.appup.src
@@ -17,18 +17,38 @@
 %% %CopyrightEnd%
 %%
 
+
 {"%VSN%",
 
 %% ----- U p g r a d e -------------------------------------------------------
 
+%% Instruction examples: 
+%% {restart_application, snmp}
+%% {load_module, snmp_pdus, soft_purge, soft_purge, []}
+%% {update, snmpa_local_db, soft, soft_purge, soft_purge, []}
+%% {add_module,  snmpm_net_if_mt}
+
  [
+  {"4.24", 
+   [
+    {update, snmpa_local_db, soft, soft_purge, soft_purge, []}
+   ]
+  }, 
   {"4.23.1", [{restart_application, snmp}]}, 
   {"4.23",   [{restart_application, snmp}]}
  ], 
 
 %% ------D o w n g r a d e ---------------------------------------------------
 
+%% Instruction examples: 
+%% {remove, {snmpm_net_if_mt, soft_purge, soft_purge}}
+
  [
+  {"4.24", 
+   [
+    {update, snmpa_local_db, soft, soft_purge, soft_purge, []}
+   ]
+  }, 
   {"4.23.1", [{restart_application, snmp}]}, 
   {"4.23",   [{restart_application, snmp}]}
  ]