Issue #3420709 by gorkagr, ressa, Ruturaj Chaubey, larowlan, alexpott: Make it more obvious that a Twig template is overridden

Issue #3261574 by quietone, kkalashnikov, alexpott, smustgrave: Add .engine to files scanned by PHPCS

Issue #3328454 by xjm, Bhanu951, jidrone, smustgrave: Replace most strpos() !== FALSE or === FALSE with str_contains()

Issue #3343198 by andy-blum, murilohp, smustgrave, safetypin: Improve documentation of hook_theme_suggestions_HOOK_alter()

Issue #3097889 by longwave, paulocs, anushrikumari, SenthilMohith, andypost, Gábor Hojtsy, catch, lauriii, Wim Leers: Remove deprecated theme functions

Issue #3094493 by longwave, Gábor Hojtsy, alexpott, naveen433, Chi, catch, andypost, Krzysztof Domański, shaal, xjm, fgm, Luke.Leber, daffie, Berdir, Fabianx, effulgentsia: Upgrade to Twig 3

(cherry picked from commit 3ab61299)

Issue #3011393 by Spokje, scott_euser, TylerMarshall, markcarver, lauriii: Remove twig_without() and manual inclusion of twig.engine TwigEnvironment

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 #3072702 by alexpott, Wim Leers, mikelutz, xjm, catch, Berdir, tedbow, webchick, shaal, Mixologic, heddn: Core extensions should not need to specify the new core_version_requirement in *.info.yml files so that 9.0.x can be installed

Issue #2591515 by joelpittet, Cottser, lauriii, NickWilde, kostyashupenko, alexpott, xjm: Move twig_without() to the TwigExtension where all the other filters are and deprecate

Issue #2903908 by mfernea, martin107: Fix 'Drupal.Commenting.FunctionComment.ParamCommentIndentation' coding standard

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2388247 by pguillard, snehi, joelpittet, sriharsha.uppuluri: Documentation refers to _theme() function, which has been removed

Issue #2122087 by rakesh.gectcr, snehi, InternetDevels, Xano, alvar0hurtad0: Remove references to hook_init()

Issue #2576533 by alexpott, stefan.r, Wim Leers, dawehner, xjm, effulgentsia, catch: Rename SafeStringInterface to MarkupInterface and move related classes

Issue #2574717 by dawehner, hussainweb, lauriii, pwolanin, davidhernandez, xjm, stefan.r, webchick, Wim Leers: Remove PHPTemplate, and add test coverage for multiple theme engine support

Issue #2549393 by alexpott, dawehner, lauriii, andypost, xjm: Remove SafeMarkup::escape() and rely more on Twig autoescaping

Issue #2553969 by alexpott, dawehner, xjm: Use \Twig_Markup in twig_drupal_join_filter() since it is part of Twig and should not pollute the safe list

Issue #2501931 by alexpott, alimac, cmanalansan, davidhernandez, scotself, cilefen, RavindraSingh, peezy, YesCT, pwolanin: Remove SafeMarkup::set in twig_render_template() and ThemeManager and FieldPluginBase:advancedRender

Revert "Issue #2501931 by alexpott, alimac, cmanalansan, davidhernandez, scotself, cilefen, RavindraSingh, peezy, YesCT, pwolanin: Remove SafeMarkup::set in twig_render_template() and ThemeManager and FieldPluginBase:advancedRender"

This reverts commit 9ccb44e2.

Issue #2501931 by alexpott, alimac, cmanalansan, davidhernandez, scotself, cilefen, RavindraSingh, peezy, YesCT, pwolanin: Remove SafeMarkup::set in twig_render_template() and ThemeManager and FieldPluginBase:advancedRender

Issue #2407195 by Wim Leers, Fabianx, joelpittet, lauriii, Crell: Move attachment processing to services and per-type response subclasses

Issue #2464045 by fgm: Move twig_render_var/twig_drupal_escape_filter to TwigExtension, inject the renderer in Twig extension and inline render() / show() function instead of calling it

Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

Issue #2430981 by Cottser: Unnecessary notices when twig_render_template() catches \Twig_Error_Loader exceptions

Issue #2328111 by dawehner, martin107, neclimdul: Replace most instances of the DRUPAL_ROOT constant with the app.root container parameter.

Issue #2226207 by lauriii, mgbellaire, Cottser, m1r1k, Mark Carver, LinL, rachel_norfolk, rteijeiro, skwashd, davidhernandez, euphoric_mv: Make 'template' the default output option for hook_theme().

Issue #2201789 by joelpittet, jjcarrion, stefanos.petrakis, wiifm, Geizt, lussoluca | Cottser: Don't print '_theme()' in twig_debug output.

Issue #1332068 by Cottser, pixelmord | tim.plunkett: ENGINE_render_template() and ENGINE_extension() are undocumented.

Issue #1825952 by Fabianx, joelpittet, bdragon, heddn, chx, xjm, pwolanin, mikey_p, ti2m, bfr, dags, cilefen, scor, mgifford: Turn on twig autoescape by default

Issue #2227869 by joelpittet: Remove magic printing from Attribute class to make Twig 'without' filter work for attributes.