a bug in polynomial() for PolynomialRing(GF(5),2)

[kwankyu]

This works:

sage: R.<x,y>=PolynomialRing(QQ,2)
sage: a=x^2+x*y+y
sage: a.polynomial(x)
x^2 + y*x + y

But this does not work:

sage: R.<x,y>=PolynomialRing(GF(5),2)
sage: a=x^2+x*y+y
sage: a.polynomial(x)
Traceback (most recent call last):
...
TypeError: 'tuple' object cannot be interpreted as an index 

I traced this bug, and found that

sage: B=QQ[x]
sage: print B({0:1,1:2})
2*x + 1
sage: print B({(0,):1,(1,):2})
2*x + 1
sage: B=GF(5)[x]
sage: print B({0:1,1:2})
2*x + 1
sage: print B({(0,):1,(1,):2})
Traceback (most recent call last):
...
TypeError: 'tuple' object cannot be interpreted as an index

I think the second form is not acceptable. Then the function
remove_from_tuple() in sage.rings.polynomial.multi_polynomial.pyx
should be revised as it output (1,) from (1,2) for example.

Component: basic arithmetic

Author: Kwankyu Lee

Reviewer: Mike Hansen

Merged: 4.0.rc0

Issue created by migration from https://trac.sagemath.org/ticket/6036

[kwankyu]

Attachment: 12159.patch.gz

[kwankyu]

Attachment: 12160.patch.gz

[mwhansen]

comment:4

Attachment: trac_6036.patch.gz

I attached a folded patch -- it should be applied instead of the other two.

Looks good to me.

[sagetrac-mabshoff]

comment:5

Merged trac_6036.patch in Sage 4.0.rc0.

Cheers,

Michael

[loefflerd]

Reviewer: Mike Hansen

[loefflerd]

Author: Kwankyu Lee

[loefflerd]

Merged: 4.0.rc0