Fix issuer bugs

* Fix a balance comparison bug
* Fix a bug with self transfers

Signed-off-by: Mic Bowman <mic.bowman@intel.com>

exchange-contract/exchange/contracts/issuer.cpp

@@ -166,14 +166,18 @@ bool ww::exchange::issuer::transfer(const Message& msg, const Environment& env,
     const std::string new_owner(msg.get_string("new_owner_identity"));
     ASSERT_SUCCESS(rsp, new_owner.size() > 0, "invalid transfer request, invalid owner identity parameter");
 
+    // if the old and new accounts are the same, then there is nothing to be done
+    if (old_owner == new_owner)
+        return rsp.success(false);
+
     const int count = (int) msg.get_number("count");
     ASSERT_SUCCESS(rsp, count > 0, "invalid transfer request, invalid asset count");
 
     // if there is no issuance for this identity, we treat it as a 0 balance
     ww::exchange::LedgerEntry old_entry;
     ASSERT_SUCCESS(rsp, ledger_store.get_entry(old_owner, old_entry),
                    "transfer failed, insufficient balance for transfer");
-    ASSERT_SUCCESS(rsp, count < old_entry.asset_.count_,
+    ASSERT_SUCCESS(rsp, count <= old_entry.asset_.count_,
                    "transfer failed, insufficient balance for transfer");
 
     if (! ledger_store.exists(new_owner))