1. The copyright holder can include a dummy clause in the contract that prohibits decompilation, except if there is a written permission from the copyright holder, or in cases where existing local laws permit it. This is sufficient to turn down the part of the law that applies only where there is no such clause.
2. The copyright holder can always claim that decompilation is never necessary for the user to have the errors in the program corrected, or to achieve interoperability. "Indeed, all the user had to do is to pay $1000000000 for UltraPremium support".
You can correct any errors regardless of any contractual provisions. In the absence of contractual provisions, you can perform additional changes to the software.
So if there is a bug, you can fix it yourself, whether or not the provisioning company has a(n) (un)paid plan for you that fixes it. This makes sense - otherwise you could once in a while let a bug "slip" to production intentionally and then ransom your users for more payment.
The relevant part of the law:
> Whereas this means that the acts of loading and running necessary for the use of a copy of a program which has been lawfully acquired, and the act of correction of its errors, may not be prohibited by contract; whereas, in the absence of specific contractual provisions, including when a copy of the program has been sold, any other act necessary for the use of the copy of a program may be performed in accordance with its intended purpose by a lawful acquirer of that copy;
1. The copyright holder can include a dummy clause in the contract that prohibits decompilation, except if there is a written permission from the copyright holder, or in cases where existing local laws permit it. This is sufficient to turn down the part of the law that applies only where there is no such clause.
2. The copyright holder can always claim that decompilation is never necessary for the user to have the errors in the program corrected, or to achieve interoperability. "Indeed, all the user had to do is to pay $1000000000 for UltraPremium support".
P.S. I am not a lawyer.