Magma V2.25-2 Patch Notes

Complex Field¶

• A bug in computing the complex roots of a polynomial has been fixed. Reported by S. Humphries.

Groups¶

• Some small fixes have been made for GL(n, Z) conjugacy testing.
• The production of fp-groups with trivial relations by the Simplify functions has been fixed. Bug reported by D. Holt.
• The free group subgroup code has been extended to recognise some free subgroups of non-free groups. In response to an example from D. Holt.

Hyperelliptic Curves¶

• Arithmetic on Jacobians over inexact rings is now disallowed, as the underlying algorithm (Cantor's) is not suitable for this, leading to crashes and superfluous results. Noted by M. Stoll.
• The TorsionBound for Jacobians of hyperelliptic curves over the rationals now never considers the prime 2 to be good. This caused problems with Order in some instances. Reported by A. Sutherland.
• A memory leak with searching for points on Jacobians was fixed. Reported by M. Stoll.

I/O¶

• Added a simpler version of Seek that assumes the desired offset is relative to the start of the channel.
• Fixed a bug that caused WaitForIO to disallow server sockets.
• Fixed a bug that prevented version exchange from working.
• Fixed a bug that would prevent further writes to a channel after attempting to write an object of a type not yet supported.
• Calling WaitForIO with an empty channel list no longer gives an error. Consequently, Sleep now works again, since it uses that method to perform the wait.

Quadratic Fields¶

• Conductors of orders of quadratic fields $> 2^30$ are now handled better.

Riemann Surfaces¶

• A crash in RiemannSurface involving root finding has been fixed. Reported by R. van Bommel.

Schemes¶

• JacobianMatrix and JacobianIdeal now use a minimal basis of the defining ideal of a scheme if this is smaller than the set of original defining polynomials. This change also affects IsNonsingular and JacobianSubrankScheme. Change suggested by M. Reid.

System¶

• The use of shorthands such as [RngIntElt] instead of SeqEnum[RngIntElt] in intrinsic arguments now works properly with reference arguments. Reported by M. Joaquin.
• The term "multi-iteration" has been changed to "dual iteration" in error messages.

Twisted Polynomials¶

• Some problems with twisted polynomials have been fixed. Reported by A. Joux.