PARI 2.16.0

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

Dear PARI developers,

In anticipation of the PARI atelier next week as part of conference COUNT,
I have released a snapshot of the development branch 2.16 as pari 2.16.0.alpha,
see <https://pari.math.u-bordeaux.fr/download.html>

Cheers,
Bill

P.S.: the changelog:

Bug numbers refer to the BTS at http://pari.math.u-bordeaux.fr/Bugs/

Done for version 2.16.0 (released 25/02/2023):
  Fixed
BA   1- ploth long help was misformatted
     2- polredbest(y^4 - y^3 - 1/4, 1) -> Error [#2414]
     3- mathnf over polynomial rings: wrong when rank not maximal [#2415]
BA   4- seralgdep(Ser([0,1,0,u]*Mod(1,(u^2+u+1)*Mod(1,2)),y),2,2) -> SEGV
     5- polroots(4*x^3+4*x^2+28*x+144) -> overflow [#2418]
     6- conversion to float of t_QUAD with t_FRAC components [#2419]
     7- bnfinit(x^3-810693844986180*x-30702939461011257135364,1).fu
        -> wrong result or SEGV [#2420]
     8- [1,2]*[3,4] -> strange error message about qfbcomp
     9- obscure oo loop in solve when solution ~ 0 [#2412]
    10- polcyclo(huge n, t_PADIC of positive valuation) -> overflow
    11- charpoly over R or C was unstable [#2406]
    12- polredbest: rare error "inconsistent concatenation" [#2423]
    13- hypergeom([0,0],[1],2) -> SEGV [#2425]
    14- fromdigitsu(v, B) actually computed fromdigitsu(v, |B|)
    15- powers(t_INT, ...) was very slow
    16- factor(prod(i=1,20,nextprime(2^i)), 131) would include 131 instead of
        stopping at 67
    17- sumeulerrat(x^2/(1+x),2) -> FPE [#2433]
    18- lambertw(10^1000) -> overflow [#2429]
    19- rare infinite loop in idealtwoelt [#2437]
BA  20- nfisisom(16*x^4+1,16*x^4+1) -> error [#2432]
    21- forprimestep(p=a,b,q,) overflow when a > primelimit and q large [#2439]
BA  22- lfun([bnrinit(bnfinit(y^2+1),12),[[2,0],[6,0]]],2) -> error
    23- lfunthetacost(polcyclo(43)): silent overflow
BA  24- ellcard(ellinit([1,1]*ffgen([41,16])))-> impossible inverse [#2441]
    25- wrong result (missing content) in idealred(nf, [id, elt])
    26- det(integer matrix) -> inconsistent exact division [#2445]
BA  27- fft([],[]) -> SEGV, fft([1],[1]) -> SEGV
BA  28- nfrootsof1(x^0) -> oo-loop
BA  29- hgmalpha did not check its input
BA  30- hyperellchangecurve([],[]) -> SEGV
BA  31- hyperellchangecurve(x^0,[1,matid(2),0]) -> SEGV
BA  32- rnfeltnorm(x,x) -> SEGV
BA  33- polylogmult(1,[],-1) -> SEGV
    34- ellheight(non-integral E) -> crash [#2448]
    35- content(1,y) -> pol_1(y) instead of t_INT 1
    36- s=taylor(1/((x-1)*(y-1)),x); taylor(s,y) -> invalid object [#2452]
    37- avoid crashing when sumnumsidi diverges (0 bits of accuracy) [#2454]

  Changed
     1- binomial(negative t_INT, t_INT): use Loeb's definition
     2- normalize t_RFRAC so that leading coeff of denoimator is "positive";
        compare: 1/(1-x) and 1/(x-1)
     3- t_SER: valser, evalvalser, setvalser need to be used instead of
               valp, evalvalp, setvalp
     4- mathess over R or C: use maximal pivot instead of first non-zero
     5- default 'parisize' is now 8M on both 32bit and 64bit architectures
     6- default 'realprecision' is now 38 on both 32bit and 64bit architectures
     7- default 'realbitprecision' is now 128 on both 32bit and 64bit
        architectures
     8- default 'primelimit' is now 2^20 [instead of 500000]
     9- allow fromdigits(t_COL or t_VECSMALL, B)
    10- [libpari] cgetalloc arguments swapped to mirror cgetg's definition
    11- simplified lfunabelianrelinit (absolute equation is now optional)

  Added
PMo  1- new syntax for forvec loops
BA   2- [GP] genus2igusa
     3- printf numerical conversions: support complex numbers [#2431]
     4- libpari vecsmall_counting_indexsort, vecsmall_counting_sort
        vecsmall_counting_uniq
BA   5- [riscv64] add riscv64 assembly kernel
BA   6- lfuncreate([bnr, subg]): Dedekind zeta for the corresponding Abelian
        extension.

  Removed
BA   1- [GP] lfunabelianrelinit. Use lfunfinit([bnr, subgroup]) instead.