I think it's possible to make a distinction. E.g., contract-law could be about the laws that govern the interpretation and limitations of contracts in general, while contract would for questions about contracts themselves.
An example of contract-law: Is a contract that involves illegal actions enforceable?
An example of contract: Is it possible to use a contract to indemnify duelers?
But, as we can see here, the distinction is very hard to discern because the principles of the former almost always inform answers to the latter.
Therefore: We should synonymize these, and, following @cpast's rule1 make contract a synonym for contract-law.
1Use the phrase that someone would actually use instead of trying a this-site-specific contraction.