seq: Output mismatch

[Carbrex]

$ cargo run seq 11e4931 11e4931
    Finished dev [unoptimized + debuginfo] target(s) in 0.10s
     Running `target/debug/coreutils seq 11e4931 11e4931`
1100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
                                                                                                                                                                                   
$ seq 11e4931 11e4931
1099999999999999999974373107528241817659030869279043407734988001817024145106513112504247507989334878520248308281361039478032934883265306874247558219180296632615879769284426144446587301862925949044860103916345584575444940764072805023841127038694056136469796496577126541639538344365510095288710750981114492840403606011035722140950388865380426626956598546884662554156676899849274474003946737153202663113471019038507440355784997612447212190315662150842498356408074864010786635463165434158504462993091203108212159354301043245621277048030590981217752749212401923243127138342167748918430168950395586853357811402450292366170936077374287304280516496791243181744660062034825766801562331288150173113824584687813457202545074014431803319775315998574294061353416922646887741547820181608294728217534644103487399058533712092272305657732870431777406038928081305932744454766811852554655135914113871013315952423872114812576001290757699422940111221911945045555478113741593424829620020501745005161710852074978186012721939150513407866391014807697433774795954470026204995541086095733716024007432033404098852964387711906037511284559079635511511105265001649140398250845901004463286876433863964550221008676952276372763575067911963853973001567055756406569343128045403641205087980394365831369003383371685227603278316511752728825492551800986973888739380062196017445702056808445069966439845998936831463863177685365729564195287455361289677323687699873017110388717240797343316362732376481099624642042706786493959231517121398104419805714616715338680064974161422455804452567918920783640928588852013556050411583586757800270730283623088608996390812328255730910963083908032153603402103429802759514853593616153177067415500911713676922818119941758485502483713233836391339711841574287048214054398466058177648133951583659697856319367061612039944071671309477097363997509664406124665760289811187313097505600091492012780926469541380190748595297191682855137672939243900595892243809281653980678128535594541228440218634574770280704029980829588473167907433901747603664817549052020034363401122401934497142344372734618140572998330462995589527034982774919647972676484630128249232151111400418665059666503407412833853472426302097183776179610563338678157970778598436154852230047505079011474601450756518383098667900525033393730130873831407982398320863044521090953981107647680374498820504991155090311321944715075464093659603368699803397944284348470932230600497140776992039106460467277241357274444180967598387038056950513122745966308365514701933261279467260780160047872244699873110020313983169069446477846410770223000745472326974222305733387182924217259845948288427247030039382730488672890229875724957711454218804526205902529773029920794664316040495109529187373742219119822413974416337644618016902599598961368374895207391065016376787494616448057680729910798524806625099187066004462348989545247911652754375344583008535499532314813905020948248399115016943815715937994396941618435619169772385095396152416767195742049851747613446789499374318798671625381003617099318979921187323092570719108388936497413021570787532233753573732786708918585920746076107959919806474257304522391293937223772917858124175606129639031362747570161480150988788136235047002696138807315834676967498996056893633045100327055704032355749831583184677746838894850303565926247689146391879788439427269920324541554278141768823388006416617704470227965980425854679637276674238801946369896560455431159381910870233417834630593573883650136801998237960628020208247398481757468084566811835562055730279594121590811427373679641364043894097024788364847476979150654114561895755972439261022946239838345042369327640360307656142990885171448040586898198259723915086866804741833530114682089637546435457028154781181140931264907183459409078936729981544306081683010025321003041561883391470801186929063790223066325097692289553470222652062743716817355209725137427212444146559934968597141351682488626743327756829921471593990068872438225701901480173844607644558335922716519091818910648440929906650467666042330589650648201165134007539549842213154851674975025009949919518589140278940864888841740301067579841024563714682594585397073634656151707861040438536974108573443444281454191384584475697323062320067494855247657937783341904958252264900431607261250517735640918806139627134190829662969929928161163150996697459754147389369654546789346295061279066556987634926829726090875108170773496087213988428078725430074999430133270176603727855456303366522730112671767574399401456844648538462547659531008270166403919064525301187429965384383165284377279321704286099496402949518133649750949806158890635637969041636190902934947020628579214382009278904086610444871161338666575623527742889622596223558611437936647589192801663915111889094971481486408327912032020150988471330536026172285448434458991524947597084554968263341074076517000345409674031798358143745760733861343415397393159190284273438760077636163984763308746185933756214688892548733454529957267178522323242088136704

I think this can only be fixed by seq using float-128
Related #6235 #6182

[BenWiederhake]

In some sense, our result is "more correct" though. Where do we draw the line between "GNU compatibility" and "correctness"?

[maxer137]

I had some discussion with some friends about this. I would hope it's not the case, but I can image some people checking the output of seq to see if a number is a proper float. If they do, then I worry about their scripts in general.
But it would be solvable with an optional flag. For example, adding a --bigdecimal for "more correct" output.
Otherwise, it would use floats with all the floating-point errors left in, thus being GNU compatible.