BIP374: fix division logic in truediv method of FE class #1773

1. 
   brawncode commented at 7:20 pm on February 25, 2025: contributor

   I noticed an issue in the __truediv__ method of the FE class where the division was being performed incorrectly. The method was returning FE(self, a), which doesn’t account for the numerator and denominator fields (_num and _den).

   To fix this, I’ve updated the code to return FE(self._num, self._den * a), which properly creates a new FE object with the same numerator and the denominator multiplied by the given argument a.

2. fix: Fix division logic in __truediv__ method of FE class e1789b6b5b
3. jonatack renamed this:
   fix: Fix division logic in __truediv__ method of FE class
   BIP374: fix division logic in __truediv__ method of FE class
   on Feb 25, 2025
4. jonatack added the label Bug fix on Feb 25, 2025
5. 
   murchandamus commented at 7:43 pm on February 25, 2025: contributor

   cc: @andrewtoth
6. 
   stratospher commented at 3:51 am on February 26, 2025: contributor

   don’t think there’s a problem since the initialiser method has support for both FE and int. see code comments in the __init__ method.

   this line - https://github.com/bitcoin/bips/blob/6d2f0d64fc226661bd8dced658aca8c575fb42e1/bip-0374/secp256k1.py#L34-L36 sets the numerator and denominator (_num and _den) with self’s numerator and denominator. so we don’t need to pass them separately to the initialiser method.

7. 
   andrewtoth commented at 2:49 pm on February 26, 2025: contributor

   This file was mostly taken from https://github.com/bitcoin/bitcoin/blob/master/test/functional/test_framework/crypto/secp256k1.py#L79-L81, so should likely be fixed upstream if it’s a problem.
8. murchandamus added the label PR Author action required on Feb 26, 2025
9. jonatack removed the label Bug fix on Feb 26, 2025
10. 
    jonatack commented at 10:36 pm on February 26, 2025: member

    Seems best to close here unless the reference implementation in libsecp changes or is incorrect, @brawncode what do you think?
11. murchandamus removed the label PR Author action required on Feb 27, 2025
12. 
    jonatack commented at 11:48 pm on February 27, 2025: member

    @brawncode feel free to comment here if there is a reason to re-open this.
13. jonatack closed this on Feb 27, 2025

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Contributors
brawncode murchandamus stratospher andrewtoth jonatack