* Make auto check manual merge as a chooseable mod and add manual merge way on ui

as title, Before this pr, we use same way with GH to check manually merge.
It good, but in some special cases, misjudgments can occur. and it's hard
to fix this bug. So I add option to allow repo manager block "auto check manual merge"
function, Then it will have same style like gitlab(allow empty pr). and to compensate for
not being able to detect THE PR merge automatically, I added a manual approach.

Signed-off-by: a1012112796 <1012112796@qq.com>

* make swager

* api support

* ping ci

* fix TestPullCreate_EmptyChangesWithCommits

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

* Apply review suggestions and add test

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

* fix build

* test error message

* make fmt

* Fix indentation issues identified by @silverwind

Co-authored-by: silverwind <me@silverwind.io>

* Fix tests and make manually merged disabled error on API the same

Signed-off-by: Andrew Thornton <art27@cantab.net>

* a small nit

* fix wrong commit id error

* fix bug

* simple test

* fix test

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* [Enhancement] Allow admin to merge pr with protected file changes

As tilte, show protected message in diff page and merge box.

Signed-off-by: a1012112796 <1012112796@qq.com>

* remove unused ver

* Update options/locale/locale_en-US.ini

Co-authored-by: Cirno the Strongest <1447794+CirnoT@users.noreply.github.com>

* Add TrN

* Apply suggestions from code review

* fix lint

* Update options/locale/locale_en-US.ini

Co-authored-by: zeripath <art27@cantab.net>

* Apply suggestions from code review

* move pr proteced files check to TestPatch
* Call TestPatch when protected branches settings changed

* Apply review suggestion @CirnoT

* move to service @lunny

* slightly restructure routers/private/hook.go

Adds a lot of comments and simplifies the logic

Signed-off-by: Andrew Thornton <art27@cantab.net>

* placate lint

Signed-off-by: Andrew Thornton <art27@cantab.net>

* skip duplicate protected files check

* fix check logic

* slight refactor of TestPatch

Signed-off-by: Andrew Thornton <art27@cantab.net>

* When checking for protected files changes in TestPatch use the temporary repository

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix introduced issue with hook

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove the check on PR index being greater than 0 as it unnecessary

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <matti@mdranta.net>
Co-authored-by: Cirno the Strongest <1447794+CirnoT@users.noreply.github.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

Replace all calls to os.Remove/os.RemoveAll by retrying util.Remove/util.RemoveAll and remove circular dependencies from util.

Fix #12339

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>

* Generate Diff and Patch direct from Pull head

Fix #10932
Also fix "Empty Diff/Patch File when pull is merged"

Closes #10934

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Add tests to ensure that diff does not change

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Ensure diffs and pulls pages work if head branch is deleted too

Signed-off-by: Andrew Thornton <art27@cantab.net>

* remove ReplaceLeft

* remove GetRepositoryByOwnerAndName chainload to models.GetRepositoryByOwnerAndName

* remove CheckUnitUser chainload to models.CheckUnitUser

* remove MakeAssigneeList

* remove DownloadDiff & DownloadPatch -> DownloadDiffOrPatch

* remove GetRandomBytesAsBase64

* remove PushUpdateDeleteTags

* remove GetUserByKeyID
(you still can resolve user by "k, err := GetPublicKeyByID; userID := k.OwnerID")

* remove BasicAuthEncode from struct package -> same function in modules/base/tools !

* remove UserID from api.utils

* remove unused func from structs package

* Add require signed commit for protected branch

* Fix fmt

* Make editor show if they will be signed

* bugfix

* Add basic merge check and better information for CRUD

* linting comment

* Add descriptors to merge signing

* Slight refactor

* Slight improvement to appearances

* Handle Merge API

* manage CRUD API

* Move error to error.go

* Remove fix to delete.go

* prep for merge

* need to tolerate \r\n in message

* check protected branch before trying to load it

* Apply suggestions from code review

Co-Authored-By: guillep2k <18600385+guillep2k@users.noreply.github.com>

* fix commit-reader

Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

* Add owner_name column for table repository for maintaince reason

* refactor

* Fix tests

* fix test

* fix bug when fork repository

Co-authored-by: zeripath <art27@cantab.net>

* Save patches to temporary files

* Remove SavePatch and generate patches on the fly

* Use ioutil.TempDir

* fixup! Use ioutil.TempDir

* fixup! fixup! Use ioutil.TempDir

* RemoveAll LocalCopyPath() in initIntergrationTest

* Default to status checking on PR creation

* Remove unnecessary set to StatusChecking

* Protect against unable to load repo

* Handle conflicts

* Restore original conflict setting

* In TestPullRequests update status to StatusChecking before running TestPatch