Opened 8 years ago

Closed 8 years ago

#1342 closed defect (fixed)

very serious bug in number field residue_field

Reported by: was Owned by: was
Priority: critical Milestone: sage-2.8.15
Component: number theory Keywords:
Cc: Merged in:
Authors: Reviewers:
Report Upstream: Work issues:
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Description

Notice that the parent of a changes below when you do a*a!!

sage: K.<z> = CyclotomicField(7)
sage: P = K.factor_integer(17)[0][0]
sage: ff = K.residue_field(P)
sage: a = ff(z)
sage: parent(a)
Residue field of Fractional ideal (17)
sage: parent(a*a)
Finite Field in z of size 17^6

This doesn't happen if 17 is replaced by something much smaller.
The problem is an optimization in finite field pari element, which
has two separate parent attributes. BAD.

Attachments (2)

trac1342.patch​ (18.9 KB) - added by was 8 years ago.
trac1342-part2.patch​ (929 bytes) - added by was 8 years ago.

Download all attachments as: .zip

Change History (4)

Changed 8 years ago by was

Changed 8 years ago by was

comment:1 Changed 8 years ago by roed

Looks good to me. -- David Roe

comment:2 Changed 8 years ago by mabshoff

  • Milestone changed from sage-2.9 to sage-2.8.15
  • Resolution set to fixed
  • Status changed from new to closed

Merged in 2.8.15.alpha2.

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