Borrowing MPAs ignores max_supply setting

[pmconrad]

Bug Description call_order_update_evaluator contains no check that an update won't increase the smartcoin's supply beyond the configured max_supply

Impacts Describe which portion(s) of BitShares Core may be impacted by this bug. Please tick at least one box.

• [ ] API (the application programming interface)
• [ ] Build (the build process or something prior to compiled code)
• [ ] CLI (the command line wallet)
• [ ] Deployment (the deployment process after building such as Docker, Travis, etc.)
• [x] DEX (the Decentralized EXchange, market engine, etc.)
• [ ] P2P (the peer-to-peer network for transaction/block propagation)
• [ ] Performance (system or user efficiency, etc.)
• [x] Protocol (the blockchain logic, consensus, validation, etc.)
• [ ] Security (the security of system or user data, etc.)
• [ ] UX (the User Experience)
• [ ] Other (please add below)

Steps To Reproduce

1. Create a bitAsset with limited supply
2. Publish feed price
3. Use call_order_update to borrow more than max_supply

Expected Behavior The call_order_update should fail.

CORE TEAM TASK LIST

• [ ] Evaluate / Prioritize Bug Report
• [ ] Refine User Stories / Requirements
• [ ] Define Test Cases
• [ ] Design / Develop Solution
• [ ] Perform QA/Testing
• [ ] Update Documentation

[pmconrad]

It may be debatable if this is actually a bug or meant as a feature. IMO it is a bug. If it is a feature, supply must at least be limited to GRAPHENE_MAX_SHARE_SUPPLY.

[cogutvalera]

IMHO it's a bug and users must be restricted to borrow more than max_supply (thus current_supply must be always less or equal to max_supply) as was adjusted per concrete asset, at the same time while creating new asset users cannot create max_supply more than GRAPHENE_MAX_SHARE_SUPPLY.

[jmjatlanta]

Fixed by #1498