Issue #3138795 by quietone, sja112, jungle, longwave: d6_term_node_revision references non-existent migration

(cherry picked from commit c30963fa)

Issue #3136406 by Spokje, codersukanta, IJsbrandy, atul4drupal, MahtabAlam, BalajiDS: Argument 1 passed to Drupal\Core\Form\SubformState::createForSubform() must be of the type array, null given

(cherry picked from commit acb4b855)

SA-CORE-2020-012 by ufku, mrf, fgm, samuel.mortenson, dww, Heine, mlhess, David_Rothstein, pwolanin, xjm, fgm, stefan.r, dsnopek, rickmanelius, David Strauss, tedbow, alexpott, dww, larowlan, kim.pepper, Wim Leers, quicksketch, mcdruid, Fabianx, effulgentsia, drumm, pandaski, Mixologic

(cherry picked from commit 1111de84)

Issue #268909 by maartenvg, raman.b, paulocs, lyricnz, Abhijith S, webchick, Freso, chx, pameeela: "0" can't be used a path alias, but no error is shown

(cherry picked from commit 29689c24)

Issue #2851504 by alexpott, vomiand, Vj, BalajiDS, cilefen, tamasd: "Illegal choice 0 in Book element" when switching the book outline field from anything to "- None - "

(cherry picked from commit 4397d8d5)

Issue #2223967 by AdamPS, jofitz, LKS90, sja112, shaktik, pminf, Berdir, mxr576, bmcclure, Manuel Garcia, naveenvalecha, Gogowitsch, andypost, alexpott, jonathanshaw, claudiu.cristea, catch, greggles: Do not decode a contact message twice

Issue #3179875 by greg.1.anderson, longwave, catch, Mixologic: Path repositories need to be listed first for Composer 2

Issue #3181173 by longwave, pefferen, JD_1, larowlan: Drupal 8.9.7 breaks Book Settings Form Validation

(cherry picked from commit 23116573)

Issue #3156651 by alexpott, dww, pfrenssen, Kristen Pol, xjm, andypost, Gábor Hojtsy, bradjones1: Prevent Drupal 8.9 and 9.0 from being installed on PHP 8

Issue #3014969 by TR, longwave, Abhijith S, joachim, shimpy: Unescaped "@" in ContextProviderInterface doc comment

(cherry picked from commit 2b76f575)
(cherry picked from commit dd91bf1d)

Issue #3132426 by alexpott, dww, GuyPaddock, catch, VladimirAus: Notice: Undefined index: title in Drupal\update\ProjectSecurityRequirement

(cherry picked from commit d7758d65)

Issue #3173004 by beram: Incorrect typehint documentation for FieldItemInterface::view() and FieldItemListInterface::view(): $display_options could also be a string

(cherry picked from commit 6a910ad4)

Issue #2716115 by LittleCoding, gapple, gnuget, jungle, alexpott, mrinalini9, tatarbj, erlendoos, sandeep_jangra, ksemihin, markcarver, NickDickinsonWilde, catch, cayriawill, geek-merlin: [backport] Allow attributes passed with CSS in libraries (SRI)

Issue #3178039 by anmolgoyal74, Matroskeen, xjm, Kristen Pol, alvar0hurtad0: Correct typo "is has" in a few code comments and tests in core

Issue #2937844 by andypost, ravi.shankar, Spokje, mrinalini9, Deepak Goyal, RoSk0, daffie, borisson_, xjm, tstoeckler: [8.9/9.0 backport] Fix 'Squiz.PHP.NonExecutableCode' coding standard

Issue #3040274 by sarvjeetsingh, ayushmishra206, rishabhthakur, alexpott, theotherlondon, kkalaskar, longwave, kiamlaluno, amarphule, ravi.shankar, gringoinc, quietone, larowlan, davidhernandez, tim.plunkett: [backport] Fix grammar, spelling, and style of the code comments in FormBuilder::prepareForm()

(cherry picked from commit 44143438)

(cherry picked from commit f60d2589)

(cherry picked from commit 7655860e)

Issue #3157963 by shailja179, ravi.shankar, kiamlaluno, davidhernandez, joachim: The link given in FormState::setRedirect() for the page explaining what values are available for $options param takes to a class documentation page

(cherry picked from commit d6b4ca71)

Issue #3177477 by Gábor Hojtsy, pameeela, Dries: Promote pameeela to non-provisional committer facilitator

(cherry picked from commit 030cc90d)

Issue #3176036 by paulocs, raman.b, longwave: Replace "does" to "do" in ProfileFieldCheckRequirementsTest.php

(cherry picked from commit 7af06a3c)

(cherry picked from commit 0af3c6a9)

Issue #3040181 by paulocs, quietone, snehalgaikwad, ravi.shankar, acbramley, alexpott, mindbet, ultrabob, bthompson1, Lendude, lapaev, pameeela, catch: Unpublished books appear in the list of books at /book

Issue #3175395 by NitinLama: Remove unused #html property from DateTimeFormatterBase::buildDateWithIsoAttribute

(cherry picked from commit 563ed8e8)

Issue #3175112 follow-up by andypost, TR: hold_test module creates files in incorrect place leading to possible random errors

Issue #3175112 by alexpott, longwave: hold_test module creates files in incorrect place leading to possible random errors

(cherry picked from commit 5e27a9f4)

Issue #3168301 by chr.fritsch, phenaproxima: oEmbed validator should use the urlResolver to get the resource URL

(cherry picked from commit e5bef54a)