Add user blocking (#29028)

Fixes #17453

This PR adds the abbility to block a user from a personal account or
organization to restrict how the blocked user can interact with the
blocker. The docs explain what's the consequence of blocking a user.

Screenshots:


![grafik](https://github.com/go-gitea/gitea/assets/1666336/4ed884f3-e06a-4862-afd3-3b8aa2488dc6)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ae6d4981-f252-4f50-a429-04f0f9f1cdf1)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ca153599-5b0f-4b4a-90fe-18bdfd6f0b6b)

---------

Co-authored-by: Lauris BH <lauris@nix.lv>

docs/content/usage/blocking-users.en-us.md

@@ -0,0 +1,56 @@
+---
+date: "2024-01-31T00:00:00+00:00"
+title: "Blocking a user"
+slug: "blocking-user"
+sidebar_position: 25
+toc: false
+draft: false
+aliases:
+  - /en-us/webhooks
+menu:
+  sidebar:
+    parent: "usage"
+    name: "Blocking a user"
+    sidebar_position: 30
+    identifier: "blocking-user"
+---
+
+# Blocking a user
+
+Gitea supports blocking of users to restrict how they can interact with you and your content.
+
+You can block a user in your account settings, from the user's profile or from comments created by the user.
+The user is not directly notified about the block, but they can notice they are blocked when they attempt to interact with you.
+Organization owners can block anyone who is not a member of the organization too.
+If a blocked user has admin permissions, they can still perform all actions even if blocked.
+
+### When you block a user
+
+- the user stops following you
+- you stop following the user
+- the user's stars are removed from your repositories
+- your stars are removed from their repositories
+- the user stops watching your repositories
+- you stop watching their repositories
+- the user's issue assignments are removed from your repositories
+- your issue assignments are removed from their repositories
+- the user is removed as a collaborator on your repositories
+- you are removed as a collaborator on their repositories
+- any pending repository transfers to or from the blocked user are canceled
+
+### When you block a user, the user cannot
+
+- follow you
+- watch your repositories
+- star your repositories
+- fork your repositories
+- transfer repositories to you
+- open issues or pull requests on your repositories
+- comment on issues or pull requests you've created
+- comment on issues or pull requests on your repositories
+- react to your comments on issues or pull requests
+- react to comments on issues or pull requests on your repositories
+- assign you to issues or pull requests
+- add you as a collaborator on their repositories
+- send you notifications by @mentioning your username
+- be added as team member (if blocked by an organization)

models/fixtures/access.yml

@@ -42,120 +42,132 @@
 
 -
   id: 8
-  user_id: 15
+  user_id: 10
   repo_id: 21
   mode: 2
 
 -
   id: 9
+  user_id: 10
+  repo_id: 32
+  mode: 2
+
+-
+  id: 10
+  user_id: 15
+  repo_id: 21
+  mode: 2
+
+-
+  id: 11
   user_id: 15
   repo_id: 22
   mode: 2
 
 -
-  id: 10
+  id: 12
   user_id: 15
   repo_id: 23
   mode: 4
 
 -
-  id: 11
+  id: 13
   user_id: 15
   repo_id: 24
   mode: 4
 
 -
-  id: 12
+  id: 14
   user_id: 15
   repo_id: 32
   mode: 2
 
 -
-  id: 13
+  id: 15
   user_id: 18
   repo_id: 21
   mode: 2
 
 -
-  id: 14
+  id: 16
   user_id: 18
   repo_id: 22
   mode: 2
 
 -
-  id: 15
+  id: 17
   user_id: 18
   repo_id: 23
   mode: 4
 
 -
-  id: 16
+  id: 18
   user_id: 18
   repo_id: 24
   mode: 4
 
 -
-  id: 17
+  id: 19
   user_id: 20
   repo_id: 24
   mode: 1
 
 -
-  id: 18
+  id: 20
   user_id: 20
   repo_id: 27
   mode: 4
 
 -
-  id: 19
+  id: 21
   user_id: 20
   repo_id: 28
   mode: 4
 
 -
-  id: 20
+  id: 22
   user_id: 29
   repo_id: 4
   mode: 2
 
 -
-  id: 21
+  id: 23
   user_id: 29
   repo_id: 24
   mode: 1
 
 -
-  id: 22
+  id: 24
   user_id: 31
   repo_id: 27
   mode: 4
 
 -
-  id: 23
+  id: 25
   user_id: 31
   repo_id: 28
   mode: 4
 
 -
-  id: 24
+  id: 26
   user_id: 38
   repo_id: 60
   mode: 2
 
 -
-  id: 25
+  id: 27
   user_id: 38
   repo_id: 61
   mode: 1
 
 -
-  id: 26
+  id: 28
   user_id: 39
   repo_id: 61
   mode: 1
 
 -
-  id: 27
+  id: 29
   user_id: 40
   repo_id: 61
   mode: 4

models/fixtures/collaboration.yml

@@ -51,3 +51,15 @@
   repo_id: 60
   user_id: 38
   mode: 2 # write
+
+-
+  id: 10
+  repo_id: 21
+  user_id: 10
+  mode: 2 # write
+
+-
+  id: 11
+  repo_id: 32
+  user_id: 10
+  mode: 2 # write

models/fixtures/issue_assignees.yml

@@ -14,3 +14,7 @@
   id: 4
   assignee_id: 2
   issue_id: 17
+-
+  id: 5
+  assignee_id: 10
+  issue_id: 6

models/fixtures/repo_transfer.yml

@@ -5,3 +5,19 @@
   repo_id: 3
   created_unix: 1553610671
   updated_unix: 1553610671
+
+-
+  id: 2
+  doer_id: 16
+  recipient_id: 10
+  repo_id: 21
+  created_unix: 1553610671
+  updated_unix: 1553610671
+
+-
+  id: 3
+  doer_id: 3
+  recipient_id: 10
+  repo_id: 32
+  created_unix: 1553610671
+  updated_unix: 1553610671

models/fixtures/repository.yml

@@ -614,8 +614,8 @@
   owner_name: user16
   lower_name: big_test_public_3
   name: big_test_public_3
-  num_watches: 0
-  num_stars: 0
+  num_watches: 1
+  num_stars: 1
   num_forks: 0
   num_issues: 0
   num_closed_issues: 0
@@ -945,8 +945,8 @@
   owner_name: org3
   lower_name: repo21
   name: repo21
-  num_watches: 0
-  num_stars: 0
+  num_watches: 1
+  num_stars: 1
   num_forks: 0
   num_issues: 2
   num_closed_issues: 0

models/fixtures/star.yml

@@ -7,3 +7,13 @@
   id: 2
   uid: 2
   repo_id: 4
+
+-
+  id: 3
+  uid: 10
+  repo_id: 21
+
+-
+  id: 4
+  uid: 10
+  repo_id: 32

models/fixtures/user.yml

@@ -361,7 +361,7 @@
   use_custom_avatar: false
   num_followers: 0
   num_following: 0
-  num_stars: 0
+  num_stars: 2
   num_repos: 3
   num_teams: 0
   num_members: 0

models/fixtures/user_blocking.yml

@@ -0,0 +1,19 @@
+-
+  id: 1
+  blocker_id: 2
+  blockee_id: 29
+
+-
+  id: 2
+  blocker_id: 17
+  blockee_id: 28
+
+-
+  id: 3
+  blocker_id: 2
+  blockee_id: 34
+
+-
+  id: 4
+  blocker_id: 50
+  blockee_id: 34

models/fixtures/watch.yml

@@ -27,3 +27,15 @@
   user_id: 11
   repo_id: 1
   mode: 3 # auto
+
+-
+  id: 6
+  user_id: 10
+  repo_id: 21
+  mode: 1 # normal
+
+-
+  id: 7
+  user_id: 10
+  repo_id: 32
+  mode: 1 # normal

models/issues/assignees.go

@@ -64,6 +64,27 @@ func IsUserAssignedToIssue(ctx context.Context, issue *Issue, user *user_model.U
 	return db.Exist[IssueAssignees](ctx, builder.Eq{"assignee_id": user.ID, "issue_id": issue.ID})
 }
 
+type AssignedIssuesOptions struct {
+	db.ListOptions
+	AssigneeID  int64
+	RepoOwnerID int64
+}
+
+func (opts *AssignedIssuesOptions) ToConds() builder.Cond {
+	cond := builder.NewCond()
+	if opts.AssigneeID != 0 {
+		cond = cond.And(builder.In("issue.id", builder.Select("issue_id").From("issue_assignees").Where(builder.Eq{"assignee_id": opts.AssigneeID})))
+	}
+	if opts.RepoOwnerID != 0 {
+		cond = cond.And(builder.In("issue.repo_id", builder.Select("id").From("repository").Where(builder.Eq{"owner_id": opts.RepoOwnerID})))
+	}
+	return cond
+}
+
+func GetAssignedIssues(ctx context.Context, opts *AssignedIssuesOptions) ([]*Issue, int64, error) {
+	return db.FindAndCount[Issue](ctx, opts)
+}
+
 // ToggleIssueAssignee changes a user between assigned and not assigned for this issue, and make issue comment for it.
 func ToggleIssueAssignee(ctx context.Context, issue *Issue, doer *user_model.User, assigneeID int64) (removed bool, comment *Comment, err error) {
 	ctx, committer, err := db.TxContext(ctx)

models/issues/issue_update.go

@@ -517,6 +517,15 @@ func FindAndUpdateIssueMentions(ctx context.Context, issue *Issue, doer *user_mo
 	if err != nil {
 		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
 	}
+
+	notBlocked := make([]*user_model.User, 0, len(mentions))
+	for _, user := range mentions {
+		if !user_model.IsUserBlockedBy(ctx, doer, user.ID) {
+			notBlocked = append(notBlocked, user)
+		}
+	}
+	mentions = notBlocked
+
 	if err = UpdateIssueMentions(ctx, issue.ID, mentions); err != nil {
 		return nil, fmt.Errorf("UpdateIssueMentions [%d]: %w", issue.ID, err)
 	}

models/issues/issue_xref.go

@@ -214,6 +214,10 @@ func (issue *Issue) verifyReferencedIssue(stdCtx context.Context, ctx *crossRefe
 		if !perm.CanReadIssuesOrPulls(refIssue.IsPull) {
 			return nil, references.XRefActionNone, nil
 		}
+		if user_model.IsUserBlockedBy(stdCtx, ctx.Doer, refIssue.PosterID, refIssue.Repo.OwnerID) {
+			return nil, references.XRefActionNone, nil
+		}
+
 		// Accept close/reopening actions only if the poster is able to close the
 		// referenced issue manually at this moment. The only exception is
 		// the poster of a new PR referencing an issue on the same repo: then the merger