Issue #3103962 by godotislate, smustgrave, alexpott, larowlan: ConfigInstaller::isSyncing() is not reset before module preinstall

Issue #2921133 by quietone, VladimirAus, xjm, ankithashetty, longwave, Prem Suthar, smustgrave, benjifisher, AaronMcHale: Remove "Please" from the codebase

Issue #3010334 by xjm, Amber Himes Matz, catch, dww, Berdir, FeyP, Mixologic: Document how contrib hook_update_N() should be numbered now that modules can be compatible with multiple major branches and versioned semantically

Issue #309040 by claudiu.cristea, David_Rothstein, Chi, BryanGullan, larowlan, dww, joachim: Add hook_requirements_alter()

Issue #2941148 by quietone, bruno.bicudo, ravi.shankar, Sweetchuck, beatrizrodrigues, lucienchalom, VitaliyB98, WagnerMelo, sophiavs, ankitjain28may, daffie, longwave, Sutharsan, borisson_, cosmicdreams, heykarthikwithu, catch: Fix Drupal.Commenting.FunctionComment.MissingReturnType

Issue #3259188 by alexpott, dww, chr.fritsch: Extend post update system to provide themes a way to install newly-required dependencies

Issue #2616814 by dpi, Xano, geek-merlin, Hardik_Patel_12, jofitz, alexpott, Fabianx, catch, joachim, andypost, dawehner, daffie, cweagans, neclimdul: Delegate all hook invocations to ModuleHandler

Issue #3138746 by jungle, rajandro, sja112, longwave, jameszhang023, quietone, dww: Fix 45 "shouldBeCamelCased" and related typos in core

Issue #3152415 by Lal_, rik-dev, Matroskeen, daffie: Bracket-encapsulated field names for static queries in core/lib/Drupal/Core

Issue #2908079 by jungle, voleger, mpdonadio, zahord, andypost, RoSk0, Mile23, claudiu.cristea, alexpott, xjm, Krzysztof Domański, naveenvalecha, piggito, Suresh Prabhu Parkala, daffie, dawehner, gumanist: Move some of the bootstrap.inc PHP-related constants to \Drupal and deprecate the old versions

Issue #3039296 by jungle, abhisekmazumdar, pandaski, tvb, dww, alexpott, init90: Fix examples in hook_install() and hook_uninstall()

Issue #3066801 by catch, WidgetsBurritos, pobster, jungle, tim.plunkett, xjm, dww, alexpott, webchick, benjifisher, longwave, worldlinemine, lauriii, Berdir: Add hook_removed_post_updates()

Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, xjm, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**

Revert "Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**"

This reverts commit 136f0550.

Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**

Issue #2914174 by larowlan, alexpott, DanielVeza: Improve hook_install() to include recommendations for config import and pass an $is_syncing argument

Issue #3047801 by Eduardo Morales, mikelutz, pguillard, nlisgo, sathish.redcrackle, Berdir: Replace all calls to the deprecated Drupal::l() function in Core

Issue #3047866 by mikelutz, Berdir, TR, alexpott, andypost, Satyanarayan Reddy: Remove usage of deprecated \Drupal::entityManager() in core

Issue #2731817 by mikelutz, ashishdalvi, Sonal.Sangale, dbt102, andypost, jhodgdon, martin107, roderik: Replace all calls to the deprecated Drupal::url() function in Core

Issue #2244513 by kim.pepper, phenaproxima, 20th, andrei.dincu, beejeebus, Berdir, alexpott, jibran, andypost, larowlan, Chadwick Wood, acbramley, Wim Leers, sun, xjm, YesCT, chx, tim.plunkett: Move the unmanaged file APIs to the file_system service (file.inc)

Revert "Issue #2244513 by kim.pepper, phenaproxima, 20th, andrei.dincu, beejeebus, Berdir, jibran, alexpott, andypost, larowlan, Chadwick Wood, Wim Leers, acbramley, YesCT, sun, tim.plunkett, chx: Move the unmanaged file APIs to the file_system service (file.inc)"

This reverts commit 56be1a03.

Issue #2244513 by kim.pepper, phenaproxima, 20th, andrei.dincu, beejeebus, Berdir, jibran, alexpott, andypost, larowlan, Chadwick Wood, Wim Leers, acbramley, YesCT, sun, tim.plunkett, chx: Move the unmanaged file APIs to the file_system service (file.inc)

Issue #2659940 by almaudoh, alexpott, phenaproxima, Jo Fitzgerald, markcarver, oriol_e9g, dawehner, dsnopek, jibran, larowlan: Extension System, Part III: ThemeExtensionList and ThemeEngineExtensionList

Issue #2937888 by dhruveshdtripathi, idebr, RoSk0, mohit1604, mfernea, borisson_: Fix 'Drupal.Commenting.DocComment.LongNotCapital' coding standard

Issue #2572613 by Malevi4, idebr, pfrenssen, Mile23, RajeevK: Fix 'Drupal.Array.Array.CommaLastItem' coding standard

Issue #2931047 by Dropa, D34dMan, borisson_, catch: hook_post_update_NAME documentation is misleading

Issue #2851468 by tameeshb, dhirendra.mishra, alexpott, joelpittet: Wrong usage of file_prepare_directory in hook_install documentation

Issue #2901739 by andriyun, Jo Fitzgerald, mfernea, xjm: Fix 'Squiz.Arrays.ArrayDeclaration' coding standard