#15653: Trac 12555 broke conversion of zero p-adics to PARI
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Reporter: jdemeyer | Owner:
Type: defect | Status: new
Priority: blocker | Milestone: sage-6.1
Component: padics | Keywords:
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
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Zero p-adics should have `precp=0`, so this is wrong:
{{{
sage: ZpFM(3,10)(0)._pari_().debug()
[&=00000000040368d0] PADIC(lg=5):0e00000000000005
(precp=10,valp=0):0002a00000000000 00000000040368b8 00000000040368a0
0000000004036890
p : [&=00000000040368b8] INT(lg=3):0200000000000003
(+,lgefint=3):4000000000000003 0000000000000003
p^l : [&=00000000040368a0] INT(lg=3):0200000000000003
(+,lgefint=3):4000000000000003 000000000000e6a9
I : [&=0000000004036890] INT(lg=2):0200000000000002
(0,lgefint=2):0000000000000002
}}}
This causes for example the following discriminant to be wrong:
{{{
sage: x = polygen(ZpFM(3,10))
sage: (x^3+x+1)._pari_().poldisc()
2 + 3 + 2*3^2 + 2*3^3 + 2*3^4 + 2*3^5 + 2*3^6 + 2*3^7 + 2*3^8 + 2*3^9 +
O(3^10)
sage: (x^3+x+1).discriminant()
2 + 3 + 2*3^2 + 3^3 + 2*3^4 + 2*3^5 + 2*3^6 + 2*3^7 + 2*3^8 + 2*3^9 +
O(3^10)
}}}
Blocker because this is a serious regression caused by #12555.
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Ticket URL: <http://trac.sagemath.org/ticket/15653>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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