Issue #2485385 by phenaproxima, quietone, Berdir, blazey, hussainweb, mikeryan, benjy, alexpott: Move highwater field support to the source plugin, and do not expose its internals on MigrationInterface

(cherry picked from commit 0308eb77)

(cherry picked from commit 0c29f756)

Issue #2799021 by dawehner, Wim Leers: Ensure a failing PHPUnit test shows enough information via run-tests.sh

(cherry picked from commit 1fdf088b)

Issue #2773333 by Berdir, Juterpillar, Wim Leers, Fabianx, renukakulkarni: Form validation errors, status messages on form submission are shown after page refresh when form is rendered in block

(cherry picked from commit 2317a396)

Issue #2657978 by maxocub, quietone, Gábor Hojtsy, Kristen Pol, alexpott:  Variable to config: language_default [d6]

(cherry picked from commit 19387f80)

(cherry picked from commit f3a83727)

Issue #2785657 by mathieso, dishabhadra, ifrik, dawehner, YesCT, tim.plunkett: Misleading text in block visibility pages description

(cherry picked from commit 09b65db3)

Issue #2787479 by Wim Leers, Sam152, quicksketch: Anon users can access editor dialogs because all users have plain_text

(cherry picked from commit 413eb510)

Issue #2791211 by cilefen: Cache::getBins should explain the returned data types implement CacheBackendInterface

(cherry picked from commit 61699f01)

Issue #2785891 by xjm, dawehner, tim.plunkett, alexpott, catch, YesCT, daffie, webchick: The distinctions between modules, themes, and other subsystems are not relevant in MAINTAINERS.txt or the issue queue component field

(cherry picked from commit 21620006)

Issue #2539634 by Berdir, dawehner, cilefen, mpp, claudiu.cristea, amateescu, kristiaanvandeneynde: PathItem::delete() never runs because the path field type is a computed field in disguise

(cherry picked from commit f3119f6a)

Issue #2797943 by jmuzz, claudiu.cristea, dawehner: Add support for clickLink()'s second argument to BrowserTestBase

(cherry picked from commit fec70c8f)

(cherry picked from commit dc509d0a)

Revert "Issue #2793443 by dawehner: Make private functions protected in BrowserTestBase/KernelTestBase"

This reverts commit 82396ae7.

(cherry picked from commit 20119bb1)

Issue #2787187 by claudiu.cristea, grahl, azinck, Fabianx, dawehner: Data loss: Deleting a translation of an entity deletes all file_usage entries for files referenced by the entity

(cherry picked from commit c64a3f7d)

Revert "Issue #2787187 by claudiu.cristea, grahl, azinck: Data loss: Deleting a translation of an entity deletes all file_usage entries for files referenced by the entity"

This reverts commit 37e041d8.

Issue #2787187 by claudiu.cristea, grahl, azinck: Data loss: Deleting a translation of an entity deletes all file_usage entries for files referenced by the entity

(cherry picked from commit a1b670fb)

Issue #2758559 by eporama, leolando.tan, kamalrajsahu21, tstoeckler, larowlan, claudiu.cristea: EntityType::setStorageClass() violates its interface

(cherry picked from commit 24d528d8)

Issue #2787641 by pwolanin, YesCT: Add non-UI mechanism for setting block weight through block forms

(cherry picked from commit ea28d669)

(cherry picked from commit bde19066)

Issue #2790111 by neclimdul, mikeryan: DrupalSqlBase doesn't include missing source in requirements exception

(cherry picked from commit 6f7f400b)

(cherry picked from commit 0e9422a3)

Issue #2786583 by claudiu.cristea, jhedstrom, effulgentsia: Create a base class for DateTimeFieldTest and DateRangeFieldTest and move common code into it

(cherry picked from commit f03979cc)

Issue #2682461 by arunkumark, jonhattan, quietone, benjy, xjm, RavindraSingh, catch: Add links to documentation in all migrate process plugins

(cherry picked from commit 0ce97fb5)

Issue #2760905 by anavarre, claudiu.cristea, amitaibu, dawehner: The documentation should be more explicit about PHPUnit requesting the webserver user to perform all functional tests

(cherry picked from commit cf37e903)

Revert "Issue #2744197 by Boobaa, Wim Leers: Proper private file support for images uploaded via EditorImageDialog"

This reverts commit 6e46381c.

Issue #2744197 by Boobaa, Wim Leers: Proper private file support for images uploaded via EditorImageDialog

(cherry picked from commit f2ed11ab)

(cherry picked from commit ed8ceb79)

(cherry picked from commit dd67ab2d)

Issue #2459289 by Lendude, dhrjgpt2005, kalistos, dawehner, david_garcia: Boolean default values are not saved

(cherry picked from commit 6c614cbf)

(cherry picked from commit 97642595)

Issue #2730973 by Wim Leers, larowlan, JonasRMuc, andypost: Comment permalinks are cached incorrectly when multiple pages exist

(cherry picked from commit 35778ab2)

Issue #2551785 by roland.molnar, nod_, MattA: Unable to scroll toolbar menu items or show contextual links on mobile browsers

(cherry picked from commit 85aea4e6)

Issue #2787135 by drpal, xjm, swentel, cashwilliams: Editing mode gets "stuck" after switching between configuration of different blocks

Issue #2792817 by Wim Leers, dawehner: BigPipe decorates html_response.attachments_processor, but uses an inner name based on the decorated service, which can cause problems

(cherry picked from commit b9aa30a0)

Issue #2560795 by chx, alexpott, mikeryan, phenaproxima, penyaskito, willwh, generalredneck, benjy: Source plugins have a hidden dependency on migrate_drupal

(cherry picked from commit 4bd0cdc0)

(cherry picked from commit f90c2462)