diff --git a/libraries/chain/asset_evaluator.cpp b/libraries/chain/asset_evaluator.cpp
index 60255490..fcf1c23e 100644
--- a/libraries/chain/asset_evaluator.cpp
+++ b/libraries/chain/asset_evaluator.cpp
@@ -20,6 +20,7 @@
 #include <graphene/chain/account_object.hpp>
 #include <graphene/chain/call_order_object.hpp>
 #include <graphene/chain/database.hpp>
+#include <graphene/chain/exceptions.hpp>
 
 #include <functional>
 
@@ -394,6 +395,8 @@ void_result asset_settle_evaluator::do_evaluate(const asset_settle_evaluator::op
    FC_ASSERT(asset_to_settle->can_force_settle() || bitasset.has_settlement() );
    if( bitasset.is_prediction_market )
       FC_ASSERT( bitasset.has_settlement(), "global settlement must occur before force settling a prediction market"  );
+   else if( bitasset.current_feed.settlement_price.is_null() )
+      FC_THROW_EXCEPTION(insufficient_feeds, "Cannot force settle with no price feed.");
    FC_ASSERT(d.get_balance(d.get(op.account), *asset_to_settle) >= op.amount);
 
    return void_result();
diff --git a/libraries/chain/call_order_evaluator.cpp b/libraries/chain/call_order_evaluator.cpp
index 379e2287..3db43f42 100644
--- a/libraries/chain/call_order_evaluator.cpp
+++ b/libraries/chain/call_order_evaluator.cpp
@@ -20,6 +20,7 @@
 #include <graphene/chain/account_object.hpp>
 #include <graphene/chain/call_order_object.hpp>
 #include <graphene/chain/limit_order_object.hpp>
+#include <graphene/chain/exceptions.hpp>
 #include <fc/uint128.hpp>
 
 namespace graphene { namespace chain {
@@ -43,8 +44,8 @@ void_result call_order_update_evaluator::do_evaluate(const call_order_update_ope
 
    if( _bitasset_data->is_prediction_market )
       FC_ASSERT( o.delta_collateral.amount == o.delta_debt.amount );
-   else
-      FC_ASSERT( !_bitasset_data->current_feed.settlement_price.is_null() );
+   else if( _bitasset_data->current_feed.settlement_price.is_null() )
+      FC_THROW_EXCEPTION(insufficient_feeds, "Cannot borrow asset with no price feed.");
 
    if( o.delta_debt.amount < 0 )
    {
diff --git a/libraries/chain/include/graphene/chain/database.hpp b/libraries/chain/include/graphene/chain/database.hpp
index 7de14fbd..0f06eb89 100644
--- a/libraries/chain/include/graphene/chain/database.hpp
+++ b/libraries/chain/include/graphene/chain/database.hpp
@@ -69,7 +69,7 @@ namespace graphene { namespace chain {
     *   @class database
     *   @brief tracks the blockchain state in an extensible manner
     */
-   class database : public object_database
+   class database : public db::object_database
    {
       public:
          //////////////////// db_management.cpp ////////////////////
diff --git a/tests/common/database_fixture.hpp b/tests/common/database_fixture.hpp
index 834f9ee0..449f3fd4 100644
--- a/tests/common/database_fixture.hpp
+++ b/tests/common/database_fixture.hpp
@@ -73,7 +73,7 @@ using namespace graphene::db;
 #define INVOKE(test) ((struct test*)this)->test_method(); trx.clear()
 
 #define PREP_ACTOR(name) \
-   fc::ecc::private_key name ## _private_key = generate_private_key(BOOST_PP_STRINGIZE(name)); 
+   fc::ecc::private_key name ## _private_key = generate_private_key(BOOST_PP_STRINGIZE(name));
 
 #define ACTOR(name) \
    PREP_ACTOR(name) \
@@ -146,10 +146,20 @@ struct database_fixture {
       );
 
    void force_global_settle(const asset_object& what, const price& p);
+   void force_settle(account_id_type who, asset what)
+   { force_settle(who(db), what); }
    void force_settle(const account_object& who, asset what);
+   void update_feed_producers(asset_id_type mia, flat_set<account_id_type> producers)
+   { update_feed_producers(mia(db), producers); }
    void update_feed_producers(const asset_object& mia, flat_set<account_id_type> producers);
+   void publish_feed(asset_id_type mia, account_id_type by, const price_feed& f)
+   { publish_feed(mia(db), by(db), f); }
    void publish_feed(const asset_object& mia, const account_object& by, const price_feed& f);
+   void borrow(account_id_type who, asset what, asset collateral)
+   { borrow(who(db), what, collateral); }
    void borrow(const account_object& who, asset what, asset collateral);
+   void cover(account_id_type who, asset what, asset collateral_freed)
+   { cover(who(db), what, collateral_freed); }
    void cover(const account_object& who, asset what, asset collateral_freed);
 
    const asset_object& get_asset( const string& symbol )const;
@@ -163,7 +173,7 @@ struct database_fixture {
                                        uint16_t market_fee_percent = 100 /*1%*/,
                                        uint16_t flags = charge_market_fee);
    const asset_object& create_user_issued_asset( const string& name );
-   const asset_object& create_user_issued_asset( const string& name, 
+   const asset_object& create_user_issued_asset( const string& name,
                                                  const account_object& issuer,
                                                  uint16_t flags );
    void issue_uia( const account_object& recipient, asset amount );