Add "Allow edits from maintainer" feature (#18002)

Adds a feature [like GitHub has](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork) (step 7).
If you create a new PR from a forked repo, you can select (and change later, but only if you are the PR creator/poster) the "Allow edits from maintainers" option.
Then users with write access to the base branch get more permissions on this branch:
* use the update pull request button
* push directly from the command line (`git push`)
* edit/delete/upload files via web UI
* use related API endpoints

You can't merge PRs to this branch with this enabled, you'll need "full" code write permissions.

This feature has a pretty big impact on the permission system. I might forgot changing some things or didn't find security vulnerabilities. In this case, please leave a review or comment on this PR.

Closes #17728

Co-authored-by: 6543 <6543@obermui.de>

1 files changed, 4 insertions, 4 deletions

diff --git a/routers/web/repo/view.go b/routers/web/repo/view.go
index 168927d101..86fc36fad7 100644
--- a/routers/web/repo/view.go
+++ b/routers/web/repo/view.go
@@ -579,7 +579,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 			ctx.Data["LineEscapeStatus"] = statuses
 		}
 		if !isLFSFile {
-			if ctx.Repo.CanEnableEditor() {
+			if ctx.Repo.CanEnableEditor(ctx.Doer) {
 				if lfsLock != nil && lfsLock.OwnerID != ctx.Doer.ID {
 					ctx.Data["CanEditFile"] = false
 					ctx.Data["EditFileTooltip"] = ctx.Tr("repo.editor.this_file_locked")
@@ -589,7 +589,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 				}
 			} else if !ctx.Repo.IsViewBranch {
 				ctx.Data["EditFileTooltip"] = ctx.Tr("repo.editor.must_be_on_a_branch")
-			} else if !ctx.Repo.CanWrite(unit_model.TypeCode) {
+			} else if !ctx.Repo.CanWriteToBranch(ctx.Doer, ctx.Repo.BranchName) {
 				ctx.Data["EditFileTooltip"] = ctx.Tr("repo.editor.fork_before_edit")
 			}
 		}
@@ -629,7 +629,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 		}
 	}
 
-	if ctx.Repo.CanEnableEditor() {
+	if ctx.Repo.CanEnableEditor(ctx.Doer) {
 		if lfsLock != nil && lfsLock.OwnerID != ctx.Doer.ID {
 			ctx.Data["CanDeleteFile"] = false
 			ctx.Data["DeleteFileTooltip"] = ctx.Tr("repo.editor.this_file_locked")
@@ -639,7 +639,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 		}
 	} else if !ctx.Repo.IsViewBranch {
 		ctx.Data["DeleteFileTooltip"] = ctx.Tr("repo.editor.must_be_on_a_branch")
-	} else if !ctx.Repo.CanWrite(unit_model.TypeCode) {
+	} else if !ctx.Repo.CanWriteToBranch(ctx.Doer, ctx.Repo.BranchName) {
 		ctx.Data["DeleteFileTooltip"] = ctx.Tr("repo.editor.must_have_write_access")
 	}
 }