Issue #2942001 by dimitriskr, alexpott, gaurav.kapoor, smustgrave, andypost, almaudoh: Deprecate ThemeHandlerInterface::rebuildThemeData() and use extension.list.theme service instead

Issue #2898274 by aleevas, piotrkonefal, borisson_, GaëlG, ankithashetty, dietr_ch, robpowell, alexpott: Uninstalled custom theme stuck in config blocking config import

Issue #3048495 by jonathan1055, quietone, rajandro, Spokje, Pooja Ganjage, andypost, kishor_kolekar, msuthars, munish.kumar, ankithashetty, ayushmishra206, ravi.shankar, naveenvalecha, longwave, Gábor Hojtsy, alexpott, smustgrave, Lendude, xjm, adityasingh, daffie: Fix Drupal.Semantics.FunctionTriggerError coding standard

Issue #371375 by Ammaletu, vasike, danflanagan8, KapilV, matt2000, Ryan Palmer, ZeiP, Andrew Answer, Madhu kumar, webchick, Berdir, kwinters, smustgrave, chx, cburschka, Jaza, moshe weitzman, zroger, zoo33, joachim, alexpott, ressa, dasj19, jlscott, quietone, blainelang, wturrell, tanc, MartysMind: Do not allow a module and theme to use the same name

Issue #2392815 by alexpott, pooja saraah, bircher, cilefen, pratik_specbee, catch, fago: Module uninstall validators are not used to validate a config import

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

Issue #3257127 by bbrala, quietone, murilohp, Spokje, anabpv, catch, xjm, Gábor Hojtsy, daffie, dww: Trigger a deprecation message when a deprecated module or theme is enabled

Issue #3204220 by longwave, catch: ModuleDependencyMessageTrait is used by core but belongs to system module

Issue #3121024 by jungle:  Remove todo in ThemeInstaller::uninstall() or refactor to share logic with module installer

Issue #474684 by bnjmnm, dawehner, tedbow, pfrenssen, JohnAlbin, ademarco, kalpaitch, vdacosta@voidtek.com, rensingh99, markcarver, jungle, jhedstrom, RobLoach, almaudoh, kevineinarsson, shaal, dpagini, thedavidmeister, sreynen, Snugug, Miguel.kode, kamkejj, alexpott, Pol, sun, Wim Leers, lauriii, tim.plunkett, eaton: Allow themes to declare dependencies on modules

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

Issue #2885309 by vaplas, drewklein, pk188, alexpott, Ayesh, arunkumark, andypost, klausi, xjm, mondrake: [PHP 7.2] each() function is deprecated

Issue #2901562 by mfernea, Jo Fitzgerald, Yogesh Pawar, 3ssom, Mile23, borisson_: Fix 'Squiz.WhiteSpace.SuperfluousWhitespace' 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 #2853163 by douggreen: ThemeInstaller is missing protected variable declaration for injected themeHandler

Issue #2667242 by Anul, felribeiro, eojthebrave, pranavbabbar: Use consistent terminology when referencing administration themes in the UI (not "admin theme")

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2465887 by dawehner, amateescu, tim.plunkett: Extract the install/uninstall functionality to a ThemeInstaller