Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.60
Broken: version: 2.81 (sub 3), branch: master, commit date: 2019-08-24 15:59, hash: rB6bb2912704ba
Short description of error
[Please fill out a short description of the error here]
This all belongs somehow to each other.
Parent - Follow Path does not add a Follow Path constraint. The functionality is there. But the constraint is missing in the constraints settings panel in the properties editor.
Parent - Path Constraint does not add a path constraint, but a AutoPath constraint that has the same functionality than Follow Path constraint. And might be in fact a Follow Path constraint.
AutoPath constraint is not in the list of constraints. And so once removed you can't add it back from the list of constraints.
AutoPath constraint is not documented.
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
Create an object. Create a curve. Parent the cube to the curve with Follow Path. The functionality is there. But the constraint will not appear at the cube in its constraints list. Means you cannot change the curve afterwards.
Create an object. Create a curve. Parent the cube to the curve with Path Constraint. The AutoPath constraint will be added. Looks similar to Follow Path. And when it's really the same then we might have one operator too much in the parent menu.