What is the quality of Random class implementation in .NET?

Question

I have two questions regarding implementation of Random class in .NET Framework 4.6 (code available here):

1. What is the rationale for setting Seed argument to 1 at the end of the constructor? It seems to be copy-pasted from Numerical Recipes in C (2nd Ed.) where it made some sense, but it doesn't have any in C#.

2. It is directly stated in the book (Numerical Recipes in C (2nd Ed.)) that inextp field is set to value 31 because:

The constant 31 is special; see Knuth.

However, in the .NET implementation this field is set to value 21. Why? The rest of a code seems to closely follow the code from book except for this detail.

Answer 1

Regarding the intexp issue, this is a bug, one which Microsoft has acknowledged and refused to fix due to backwards compatibility concerns.

Indeed, you have discovered a genuine problem with the Random implementation. We have discussed it within the team and with some of our partners and concluded that we unfortunately cannot fix the problem right now. The reason is that some applications rely on the fact that when initialised with the same seed, the generator produces the same pseudo random sequence. Even if the change is for the better, it will break the applications that made this assumption once they have migrated to the “fixed” version.