Issue #3123326 by Neslee Canil Pinto, longwave, Berdir: Remove pathauto version check from 9.0, no incompatible version is Drupal 9 compatible

Issue #3043471 by longwave, catch, Wim Leers, xjm: Replace the DiactorosFactory message factory in symfony/psr-http-message-bridge with a PSR-17 compliant message factory

Issue #3020296 by alexpott, longwave, bradjones1, catch, Berdir, gapple: Remove Symfony's classloader as it does not exist in Symfony 4

Issue #3110862 by longwave, alexpott, catch, Mile23, Lendude, Gábor Hojtsy, Berdir: Remove simpletest module from core

Issue #3104354 by longwave, TravisCarden, xjm, catch, alexpott, Wim Leers: Update Laminas components including Diactoros

Issue #3106075 by Krzysztof Domański, heddn, Gábor Hojtsy, xjm, catch, mondrake, larowlan, greg.1.anderson: Bump minimum PHP for Drupal 9 to PHP 7.3

Issue #3104015 by TravisCarden, alexpott, longwave, Spokje, fgm, catch, xjm, Berdir, Bruno Vincent: Replace ZendFramework/* dependencies with their Laminas equivalents

Issue #3104265 by longwave, catch, xjm, TravisCarden: Update Composer dependencies on Doctrine components in 9.0.x

Issue #3104473 by Manuel Garcia, Mile23, greg.1.anderson, longwave, xjm: Use version of guzzlehttp/guzzle ^6.5.2

SA-CORE-2019-012 by samuel.mortenson, larowlan, pwolanin, Sam152, Jasu_M, David_Rothstein, michieltcs, Ayesh, alexpott, xjm, vijaycs85, mcdruid

Issue #2901363 by alexpott, Mile23, shubham.prakash, prithvi1972, Jaesin, cilefen, borisson_, runeasgar: Move easyrdf/easyrdf to require-dev

Issue #3084983 by plach, amateescu, catch, Berdir, xjm: Move all the code related to path aliases to a new (required) "path_alias" module

Issue #3041076 by alexpott, shaal, Gábor Hojtsy, lauriii, Wim Leers, catch, Cottser, jibran, andypost, znerol, xim, joelpittet, effulgentsia: Update Drupal 9 to Twig 2

Issue #3087531 by alexpott, jibran, gnikolovski, xjm, Mixologic: Use Diactoros LTS version 1.7, not 1.8 which is out of security coverage

Issue #3085062 by jibran, amateescu, larowlan, xjm, Berdir: Declare a conflict on pathauto versions that aren't compatible with 8.8.0

Issue #3088853 by alexpott, mondrake: Require typo3/phar-stream-wrapper ^3.1.3 and pear/archive_tar ^1.4.8 in order to support PHP 7.4

Issue #3088369 by mikelutz, alexpott, Berdir, Gábor Hojtsy, andypost, martin107, greg.1.anderson, dawehner, jibran, Wim Leers, Mile23, catch: Update Drupal 9 to Symfony 4.4-dev

Issue #3079791 by mikelutz, shaal, Wim Leers, hussainweb, xjm, catch, Charlie ChX Negyesi, Mixologic, Gábor Hojtsy, heddn, amateescu: Bump Drupal's minimum PHP version to 7.2 as soon as 9.0.x is branched (a higher version may be required later)

Issue #3079738 by lauriii, saschaeggi, webchick, xjm, andrewmacpherson, shimpy, effulgentsia, Wim Leers, DyanneNova, svettes, rainbreaw, fhaeberle, ckrina, AaronMcHale, justafish, catch, charlieweb82, AntoineH, lot007, pzajacz, kostyashupenko, jasonbarrie, antonellasevero, finnsky, worldlinemine, bnjmnm, RobLoach, Dennis Cohn, huzooka, Archita Arora, joachim, jrockowitz, benjifisher, shaal, Gábor Hojtsy, quiron, L2G2, ccasals, hampercm, if-jds, abhisekmazumdar, Kami Amiga, pivica, zrpnr, BrightBold, imalabya, jhedstrom, Neslee Canil Pinto, maliknaik, junaidmasoodi, Maithri Shetty, pranav73, mandclu, modulist, nod_, philosurfer, phenaproxima, mherchel, mlncn, rafuel92, leymannx, kiboman, Swapnil_Kotwal, anevins, evankay, rfmarcelino, thamas, brianperry, idebr, joelpittet, boulaffasae, alexpott, volkerk, DuneBL, Eli-T, Mahenkvyas22: Add Claro administration theme to core

Issue #3087531 by jibran, xjm: Use Diactoros LTS version 1.7, not 1.8 which is out of security coverage

Issue #3086148 by greg.1.anderson, hussainweb, Mixologic: Make scaffold "extra" data key conform with plugin command name

Issue #3084326 by hussainweb, greg.1.anderson: Install .editorconfig and .gitattributes at the project root

Issue #3045483 by Wim Leers, alexpott, RandomNeighbour, mikelutz, jibran: Incompatibility between zend-diactoros and psr-http-message-bridge versions: require symfony/psr-http-message-bridge >=1.1.2

Issue #3067645 by greg.1.anderson, Mile23, Mixologic: Add core scaffold assets to drupal/core's composer.json extra field

Issue #3013210 by kim.pepper, greg.1.anderson, Mile23, joachim: Add drupal/core-filesecurity component for writing htaccess files

Issue #2912387 by greg.1.anderson, Mile23, Mixologic, larowlan, jibran, alexpott, catch: Stop using wikimedia/composer-merge-plugin

Revert "Issue #2912387 by greg.1.anderson, Mixologic, Mile23, alexpott, catch: Stop using wikimedia/composer-merge-plugin"

This reverts commit 5cd26f24.

Issue #2912387 by greg.1.anderson, Mixologic, Mile23, alexpott, catch: Stop using wikimedia/composer-merge-plugin

Issue #2982684 by greg.1.anderson, Mile23, Mixologic, webflo, alexpott, yogeshmpawar, pingwin4eg, vijaycs85, larowlan, dww, borisson_, phenaproxima, kim.pepper, bojanz, grasmash, hctom, kmbremner, pingers, Jax, sherakama, derhasi, claudiu.cristea, jhedstrom, Xano, Grimreaper: Add a composer scaffolding plugin to core

Issue #2920309 by jhodgdon, Amber Himes Matz, alexpott, larowlan, andypost, vadim.hirbu, effulgentsia, diqidoq, jibran, webchick, catch, xjm, jhedstrom, Gábor Hojtsy, dawehner, Berdir, tim.plunkett, benjifisher, markcarver, yoroy, ckrina, amateescu, gnuget, webflo, Greg Boggs, yo30, vijaycs85, SenthilMohith, andrewmacpherson, EclipseGc, sandboxpl, MariaDenysyuk, tstoeckler, miro_dietiker, Mixologic, RoloDMonkey, timmillwood, Fabianx: Add experimental module for Help Topics

Issue #3057459 by Mile23, alexpott: Add composer/composer as a dev dependency of core so that we can test Composer plugins