Hashed ID Potentially Causes Requisite Cycles

[haydenfree]

Under the following conditions the toolbox will incorrectly think that there is a requisite cycle in the curriculum due to two courses having the same ID:

• Two courses have the same name
• When the Course() constructor is called the ID is not passed as a keyword arguement
  • This means the toolbox will generate a course ID via the following
  • mod(hash(this.name * this.prefix * this.num * this.institution), UInt32)
• The prefix, num, and institution keyword args are also not passed
  • These therefore aren't used when hashing the course ID
• One of the courses lists the other as a requisite
  • The courses will have the same ID (hashed by toolbox) and be detected as a cycle

Below is an example

Course ID	Course Name	Prefix	Number	Prerequisites	Corequisites	Strict-Corequisites	Credit Hours	Institution	Canonical Name	Term
3	First-year Comp.	ENGL	101				3			1
9	First-year Comp.	ENGL	102	3			3			2

This bug only happens under the perfect set of circumstances, and was very difficult to track down...