Bug report in simple-marketplace smart contract

[academic-starter]

• AcceptOffer does not satisfy its specifications.
  

  blockchain/blockchain-workbench/application-and-smart-contract-samples/simple-marketplace/ethereum/SimpleMarketplace.sol

  Lines 65 to 73 in 1b712d6

  	function AcceptOffer() public
  	{
  	if ( msg.sender != InstanceOwner )
  	{
  	revert();
  	}
  	State = StateType.Accepted;
  	}

As documented by its following specification, AcceptOffer is only available when at OfferPlaced state.

blockchain/blockchain-workbench/application-and-smart-contract-samples/simple-marketplace/ethereum/SimpleMarketplace.json

Lines 139 to 163 in 1b712d6

	{
	"Name": "OfferPlaced",
	"DisplayName": "Offer Placed",
	"Description": "Offer has been placed for the item",
	"PercentComplete": 60,
	"Style": "Success",
	"Transitions": [
	{
	"AllowedRoles": [ ],
	"AllowedInstanceRoles": [ "InstanceOwner" ],
	"Description": "Accept the proposed offer for the item",
	"Function": "AcceptOffer",
	"NextStates": [ "Accepted" ],
	"DisplayName": "Accept Offer"
	},
	{
	"AllowedRoles": [ ],
	"AllowedInstanceRoles": [ "InstanceOwner" ],
	"Description": "Reject the proposed offer for the item",
	"Function": "Reject",
	"NextStates": [ "ItemAvailable" ],
	"DisplayName": "Reject"
	}
	]
	},

• Bug repair.
  We can fix such bug by adding statements:

    function AcceptOffer() public
    {
        // Fix
        if ( State != StateType.OfferPlaced ){
            revert();
        }
        ...