Mark PR reviews as stale at push and allow to dismiss stale approvals (#9532)

Fix #5997.

If a push causes the patch/diff of a PR towards target branch to change, all existing reviews for the PR will be set and shown as stale.
New branch protection option to dismiss stale approvals are added.
To show that a review is not based on the latest PR changes, an hourglass is shown

models/branches.go

@@ -45,6 +45,8 @@ type ProtectedBranch struct {
 	ApprovalsWhitelistTeamIDs []int64  `xorm:"JSON TEXT"`
 	RequiredApprovals         int64    `xorm:"NOT NULL DEFAULT 0"`
 	BlockOnRejectedReviews    bool     `xorm:"NOT NULL DEFAULT false"`
+	DismissStaleApprovals     bool     `xorm:"NOT NULL DEFAULT false"`
+
 	CreatedUnix timeutil.TimeStamp `xorm:"created"`
 	UpdatedUnix timeutil.TimeStamp `xorm:"updated"`
 }
@@ -155,10 +157,13 @@ func (protectBranch *ProtectedBranch) HasEnoughApprovals(pr *PullRequest) bool {
 
 // GetGrantedApprovalsCount returns the number of granted approvals for pr. A granted approval must be authored by a user in an approval whitelist.
 func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(pr *PullRequest) int64 {
-	approvals, err := x.Where("issue_id = ?", pr.IssueID).
+	sess := x.Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeApprove).
-		And("official = ?", true).
-		Count(new(Review))
+		And("official = ?", true)
+	if protectBranch.DismissStaleApprovals {
+		sess = sess.And("stale = ?", false)
+	}
+	approvals, err := sess.Count(new(Review))
 	if err != nil {
 		log.Error("GetGrantedApprovalsCount: %v", err)
 		return 0

models/migrations/migrations.go

@@ -290,6 +290,8 @@ var migrations = []Migration{
 	NewMigration("Extend TrackedTimes", extendTrackedTimes),
 	// v117 -> v118
 	NewMigration("Add block on rejected reviews branch protection", addBlockOnRejectedReviews),
+	// v118 -> v119
+	NewMigration("Add commit id and stale to reviews", addReviewCommitAndStale),
 }
 
 // Migrate database to current version

models/migrations/v118.go

@@ -0,0 +1,26 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import (
+	"xorm.io/xorm"
+)
+
+func addReviewCommitAndStale(x *xorm.Engine) error {
+	type Review struct {
+		CommitID string `xorm:"VARCHAR(40)"`
+		Stale    bool   `xorm:"NOT NULL DEFAULT false"`
+	}
+
+	type ProtectedBranch struct {
+		DismissStaleApprovals bool `xorm:"NOT NULL DEFAULT false"`
+	}
+
+	// Old reviews will have commit ID set to "" and not stale
+	if err := x.Sync2(new(Review)); err != nil {
+		return err
+	}
+	return x.Sync2(new(ProtectedBranch))
+}

models/review.go

@@ -54,6 +54,8 @@ type Review struct {
 	Content    string `xorm:"TEXT"`
 	// Official is a review made by an assigned approver (counts towards approval)
 	Official bool   `xorm:"NOT NULL DEFAULT false"`
+	CommitID string `xorm:"VARCHAR(40)"`
+	Stale    bool   `xorm:"NOT NULL DEFAULT false"`
 
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
@@ -169,6 +171,8 @@ type CreateReviewOptions struct {
 	Issue    *Issue
 	Reviewer *User
 	Official bool
+	CommitID string
+	Stale    bool
 }
 
 // IsOfficialReviewer check if reviewer can make official reviews in issue (counts towards required approvals)
@@ -200,6 +204,8 @@ func createReview(e Engine, opts CreateReviewOptions) (*Review, error) {
 		ReviewerID: opts.Reviewer.ID,
 		Content:    opts.Content,
 		Official:   opts.Official,
+		CommitID:   opts.CommitID,
+		Stale:      opts.Stale,
 	}
 	if _, err := e.Insert(review); err != nil {
 		return nil, err
@@ -258,7 +264,7 @@ func IsContentEmptyErr(err error) bool {
 }
 
 // SubmitReview creates a review out of the existing pending review or creates a new one if no pending review exist
-func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content string) (*Review, *Comment, error) {
+func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content, commitID string, stale bool) (*Review, *Comment, error) {
 	sess := x.NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
@@ -295,6 +301,8 @@ func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content strin
 			Reviewer: doer,
 			Content:  content,
 			Official: official,
+			CommitID: commitID,
+			Stale:    stale,
 		})
 		if err != nil {
 			return nil, nil, err
@@ -322,8 +330,10 @@ func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content strin
 		review.Issue = issue
 		review.Content = content
 		review.Type = reviewType
+		review.CommitID = commitID
+		review.Stale = stale
 
-		if _, err := sess.ID(review.ID).Cols("content, type, official").Update(review); err != nil {
+		if _, err := sess.ID(review.ID).Cols("content, type, official, commit_id, stale").Update(review); err != nil {
 			return nil, nil, err
 		}
 	}
@@ -374,3 +384,17 @@ func GetReviewersByIssueID(issueID int64) (reviews []*Review, err error) {
 
 	return reviews, nil
 }
+
+// MarkReviewsAsStale marks existing reviews as stale
+func MarkReviewsAsStale(issueID int64) (err error) {
+	_, err = x.Exec("UPDATE `review` SET stale=? WHERE issue_id=?", true, issueID)
+
+	return
+}
+
+// MarkReviewsAsNotStale marks existing reviews as not stale for a giving commit SHA
+func MarkReviewsAsNotStale(issueID int64, commitID string) (err error) {
+	_, err = x.Exec("UPDATE `review` SET stale=? WHERE issue_id=? AND commit_id=?", false, issueID, commitID)
+
+	return
+}

modules/auth/repo_form.go

@@ -172,6 +172,7 @@ type ProtectBranchForm struct {
 	ApprovalsWhitelistUsers  string
 	ApprovalsWhitelistTeams  string
 	BlockOnRejectedReviews   bool
+	DismissStaleApprovals    bool
 }
 
 // Validate validates the fields
@@ -462,6 +463,7 @@ type CodeCommentForm struct {
 	TreePath       string `form:"path" binding:"Required"`
 	IsReview       bool   `form:"is_review"`
 	Reply          int64  `form:"reply"`
+	LatestCommitID string
 }
 
 // Validate validates the fields
@@ -473,6 +475,7 @@ func (f *CodeCommentForm) Validate(ctx *macaron.Context, errs binding.Errors) bi
 type SubmitReviewForm struct {
 	Content  string
 	Type     string `binding:"Required;In(approve,comment,reject)"`
+	CommitID string
 }
 
 // Validate validates the fields

modules/git/repo_compare.go

@@ -112,3 +112,9 @@ func (repo *Repository) GetPatch(base, head string, w io.Writer) error {
 	return NewCommand("format-patch", "--binary", "--stdout", base+"..."+head).
 		RunInDirPipeline(repo.Path, w, nil)
 }
+
+// GetDiffFromMergeBase generates and return patch data from merge base to head
+func (repo *Repository) GetDiffFromMergeBase(base, head string, w io.Writer) error {
+	return NewCommand("diff", "-p", "--binary", base+"..."+head).
+		RunInDirPipeline(repo.Path, w, nil)
+}

modules/repofiles/update.go

@@ -477,7 +477,7 @@ func PushUpdate(repo *models.Repository, branch string, opts PushUpdateOptions)
 
 	log.Trace("TriggerTask '%s/%s' by %s", repo.Name, branch, pusher.Name)
 
-	go pull_service.AddTestPullRequestTask(pusher, repo.ID, branch, true)
+	go pull_service.AddTestPullRequestTask(pusher, repo.ID, branch, true, opts.OldCommitID, opts.NewCommitID)
 
 	if err = models.WatchIfAuto(opts.PusherID, repo.ID, true); err != nil {
 		log.Warn("Fail to perform auto watch on user %v for repo %v: %v", opts.PusherID, repo.ID, err)
@@ -528,7 +528,7 @@ func PushUpdates(repo *models.Repository, optsList []*PushUpdateOptions) error {
 
 		log.Trace("TriggerTask '%s/%s' by %s", repo.Name, opts.Branch, pusher.Name)
 
-		go pull_service.AddTestPullRequestTask(pusher, repo.ID, opts.Branch, true)
+		go pull_service.AddTestPullRequestTask(pusher, repo.ID, opts.Branch, true, opts.OldCommitID, opts.NewCommitID)
 
 		if err = models.WatchIfAuto(opts.PusherID, repo.ID, true); err != nil {
 			log.Warn("Fail to perform auto watch on user %v for repo %v: %v", opts.PusherID, repo.ID, err)

options/locale/locale_en-US.ini

@@ -1413,6 +1413,8 @@ settings.protect_approvals_whitelist_enabled = Restrict approvals to whitelisted
 settings.protect_approvals_whitelist_enabled_desc = Only reviews from whitelisted users or teams will count to the required approvals. Without approval whitelist, reviews from anyone with write access count to the required approvals.
 settings.protect_approvals_whitelist_users = Whitelisted reviewers:
 settings.protect_approvals_whitelist_teams = Whitelisted teams for reviews:
+settings.dismiss_stale_approvals = Dismiss stale approvals
+settings.dismiss_stale_approvals_desc = When new commits that change the content of the pull request are pushed to the branch, old approvals will be dismissed.
 settings.add_protected_branch = Enable protection
 settings.delete_protected_branch = Disable protection
 settings.update_protect_branch_success = Branch protection for branch '%s' has been updated.

routers/repo/pull.go

@@ -841,7 +841,7 @@ func TriggerTask(ctx *context.Context) {
 
 	log.Trace("TriggerTask '%s/%s' by %s", repo.Name, branch, pusher.Name)
 
-	go pull_service.AddTestPullRequestTask(pusher, repo.ID, branch, true)
+	go pull_service.AddTestPullRequestTask(pusher, repo.ID, branch, true, "", "")
 	ctx.Status(202)
 }
 

routers/repo/pull_review.go

@@ -37,12 +37,14 @@ func CreateCodeComment(ctx *context.Context, form auth.CodeCommentForm) {
 
 	comment, err := pull_service.CreateCodeComment(
 		ctx.User,
+		ctx.Repo.GitRepo,
 		issue,
 		signedLine,
 		form.Content,
 		form.TreePath,
 		form.IsReview,
 		form.Reply,
+		form.LatestCommitID,
 	)
 	if err != nil {
 		ctx.ServerError("CreateCodeComment", err)
@@ -95,7 +97,7 @@ func SubmitReview(ctx *context.Context, form auth.SubmitReviewForm) {
 		}
 	}
 
-	_, comm, err := pull_service.SubmitReview(ctx.User, issue, reviewType, form.Content)
+	_, comm, err := pull_service.SubmitReview(ctx.User, ctx.Repo.GitRepo, issue, reviewType, form.Content, form.CommitID)
 	if err != nil {
 		if models.IsContentEmptyErr(err) {
 			ctx.Flash.Error(ctx.Tr("repo.issues.review.content.empty"))

routers/repo/setting_protected_branch.go

@@ -245,6 +245,7 @@ func SettingsProtectedBranchPost(ctx *context.Context, f auth.ProtectBranchForm)
 			}
 		}
 		protectBranch.BlockOnRejectedReviews = f.BlockOnRejectedReviews
+		protectBranch.DismissStaleApprovals = f.DismissStaleApprovals
 
 		err = models.UpdateProtectBranch(ctx.Repo.Repository, protectBranch, models.WhitelistOptions{
 			UserIDs:          whitelistUsers,

services/pull/merge.go

@@ -64,7 +64,7 @@ func Merge(pr *models.PullRequest, doer *models.User, baseGitRepo *git.Repositor
 	}
 
 	defer func() {
-		go AddTestPullRequestTask(doer, pr.BaseRepo.ID, pr.BaseBranch, false)
+		go AddTestPullRequestTask(doer, pr.BaseRepo.ID, pr.BaseBranch, false, "", "")
 	}()
 
 	// Clone base repo.

services/pull/pull.go

@@ -5,10 +5,14 @@
 package pull
 
 import (
+	"bufio"
+	"bytes"
 	"context"
 	"fmt"
 	"os"
 	"path"
+	"strings"
+	"time"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/git"
@@ -16,6 +20,8 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
 	issue_service "code.gitea.io/gitea/services/issue"
+
+	"github.com/unknwon/com"
 )
 
 // NewPullRequest creates new pull request with labels for repository.
@@ -168,7 +174,7 @@ func addHeadRepoTasks(prs []*models.PullRequest) {
 
 // AddTestPullRequestTask adds new test tasks by given head/base repository and head/base branch,
 // and generate new patch for testing as needed.
-func AddTestPullRequestTask(doer *models.User, repoID int64, branch string, isSync bool) {
+func AddTestPullRequestTask(doer *models.User, repoID int64, branch string, isSync bool, oldCommitID, newCommitID string) {
 	log.Trace("AddTestPullRequestTask [head_repo_id: %d, head_branch: %s]: finding pull requests", repoID, branch)
 	graceful.GetManager().RunWithShutdownContext(func(ctx context.Context) {
 		// There is no sensible way to shut this down ":-("
@@ -191,6 +197,22 @@ func AddTestPullRequestTask(doer *models.User, repoID int64, branch string, isSy
 			}
 			if err == nil {
 				for _, pr := range prs {
+					if newCommitID != "" && newCommitID != git.EmptySHA {
+						changed, err := checkIfPRContentChanged(pr, oldCommitID, newCommitID)
+						if err != nil {
+							log.Error("checkIfPRContentChanged: %v", err)
+						}
+						if changed {
+							// Mark old reviews as stale if diff to mergebase has changed
+							if err := models.MarkReviewsAsStale(pr.IssueID); err != nil {
+								log.Error("MarkReviewsAsStale: %v", err)
+							}
+						}
+						if err := models.MarkReviewsAsNotStale(pr.IssueID, newCommitID); err != nil {
+							log.Error("MarkReviewsAsNotStale: %v", err)
+						}
+					}
+
 					pr.Issue.PullRequest = pr
 					notification.NotifyPullRequestSynchronized(doer, pr)
 				}
@@ -211,6 +233,78 @@ func AddTestPullRequestTask(doer *models.User, repoID int64, branch string, isSy
 	})
 }
 
+// checkIfPRContentChanged checks if diff to target branch has changed by push
+// A commit can be considered to leave the PR untouched if the patch/diff with its merge base is unchanged
+func checkIfPRContentChanged(pr *models.PullRequest, oldCommitID, newCommitID string) (hasChanged bool, err error) {
+
+	if err = pr.GetHeadRepo(); err != nil {
+		return false, fmt.Errorf("GetHeadRepo: %v", err)
+	} else if pr.HeadRepo == nil {
+		// corrupt data assumed changed
+		return true, nil
+	}
+
+	if err = pr.GetBaseRepo(); err != nil {
+		return false, fmt.Errorf("GetBaseRepo: %v", err)
+	}
+
+	headGitRepo, err := git.OpenRepository(pr.HeadRepo.RepoPath())
+	if err != nil {
+		return false, fmt.Errorf("OpenRepository: %v", err)
+	}
+	defer headGitRepo.Close()
+
+	// Add a temporary remote.
+	tmpRemote := "checkIfPRContentChanged-" + com.ToStr(time.Now().UnixNano())
+	if err = headGitRepo.AddRemote(tmpRemote, models.RepoPath(pr.BaseRepo.MustOwner().Name, pr.BaseRepo.Name), true); err != nil {
+		return false, fmt.Errorf("AddRemote: %s/%s-%s: %v", pr.HeadRepo.OwnerName, pr.HeadRepo.Name, tmpRemote, err)
+	}
+	defer func() {
+		if err := headGitRepo.RemoveRemote(tmpRemote); err != nil {
+			log.Error("checkIfPRContentChanged: RemoveRemote: %s/%s-%s: %v", pr.HeadRepo.OwnerName, pr.HeadRepo.Name, tmpRemote, err)
+		}
+	}()
+	// To synchronize repo and get a base ref
+	_, base, err := headGitRepo.GetMergeBase(tmpRemote, pr.BaseBranch, pr.HeadBranch)
+	if err != nil {
+		return false, fmt.Errorf("GetMergeBase: %v", err)
+	}
+
+	diffBefore := &bytes.Buffer{}
+	diffAfter := &bytes.Buffer{}
+	if err := headGitRepo.GetDiffFromMergeBase(base, oldCommitID, diffBefore); err != nil {
+		// If old commit not found, assume changed.
+		log.Debug("GetDiffFromMergeBase: %v", err)
+		return true, nil
+	}
+	if err := headGitRepo.GetDiffFromMergeBase(base, newCommitID, diffAfter); err != nil {
+		// New commit should be found
+		return false, fmt.Errorf("GetDiffFromMergeBase: %v", err)
+	}
+
+	diffBeforeLines := bufio.NewScanner(diffBefore)
+	diffAfterLines := bufio.NewScanner(diffAfter)
+
+	for diffBeforeLines.Scan() && diffAfterLines.Scan() {
+		if strings.HasPrefix(diffBeforeLines.Text(), "index") && strings.HasPrefix(diffAfterLines.Text(), "index") {
+			// file hashes can change without the diff changing
+			continue
+		} else if strings.HasPrefix(diffBeforeLines.Text(), "@@") && strings.HasPrefix(diffAfterLines.Text(), "@@") {
+			// the location of the difference may change
+			continue
+		} else if !bytes.Equal(diffBeforeLines.Bytes(), diffAfterLines.Bytes()) {
+			return true, nil
+		}
+	}
+
+	if diffBeforeLines.Scan() || diffAfterLines.Scan() {
+		// Diffs not of equal length
+		return true, nil
+	}
+
+	return false, nil
+}
+
 // PushToBaseRepo pushes commits from branches of head repository to
 // corresponding branches of base repository.
 // FIXME: Only push branches that are actually updates?

services/pull/review.go

@@ -18,7 +18,7 @@ import (
 )
 
 // CreateCodeComment creates a comment on the code line
-func CreateCodeComment(doer *models.User, issue *models.Issue, line int64, content string, treePath string, isReview bool, replyReviewID int64) (*models.Comment, error) {
+func CreateCodeComment(doer *models.User, gitRepo *git.Repository, issue *models.Issue, line int64, content string, treePath string, isReview bool, replyReviewID int64, latestCommitID string) (*models.Comment, error) {
 
 	var (
 		existsReview bool
@@ -73,6 +73,7 @@ func CreateCodeComment(doer *models.User, issue *models.Issue, line int64, conte
 			Reviewer: doer,
 			Issue:    issue,
 			Official: false,
+			CommitID: latestCommitID,
 		})
 		if err != nil {
 			return nil, err
@@ -94,7 +95,7 @@ func CreateCodeComment(doer *models.User, issue *models.Issue, line int64, conte
 
 	if !isReview && !existsReview {
 		// Submit the review we've just created so the comment shows up in the issue view
-		if _, _, err = SubmitReview(doer, issue, models.ReviewTypeComment, ""); err != nil {
+		if _, _, err = SubmitReview(doer, gitRepo, issue, models.ReviewTypeComment, "", latestCommitID); err != nil {
 			return nil, err
 		}
 	}
@@ -159,16 +160,36 @@ func createCodeComment(doer *models.User, repo *models.Repository, issue *models
 }
 
 // SubmitReview creates a review out of the existing pending review or creates a new one if no pending review exist
-func SubmitReview(doer *models.User, issue *models.Issue, reviewType models.ReviewType, content string) (*models.Review, *models.Comment, error) {
-	review, comm, err := models.SubmitReview(doer, issue, reviewType, content)
-	if err != nil {
-		return nil, nil, err
-	}
-
+func SubmitReview(doer *models.User, gitRepo *git.Repository, issue *models.Issue, reviewType models.ReviewType, content, commitID string) (*models.Review, *models.Comment, error) {
 	pr, err := issue.GetPullRequest()
 	if err != nil {
 		return nil, nil, err
 	}
+
+	var stale bool
+	if reviewType != models.ReviewTypeApprove && reviewType != models.ReviewTypeReject {
+		stale = false
+	} else {
+		headCommitID, err := gitRepo.GetRefCommitID(pr.GetGitRefName())
+		if err != nil {
+			return nil, nil, err
+		}
+
+		if headCommitID == commitID {
+			stale = false
+		} else {
+			stale, err = checkIfPRContentChanged(pr, commitID, headCommitID)
+			if err != nil {
+				return nil, nil, err
+			}
+		}
+	}
+
+	review, comm, err := models.SubmitReview(doer, issue, reviewType, content, commitID, stale)
+	if err != nil {
+		return nil, nil, err
+	}
+
 	notification.NotifyPullRequestReview(pr, review, comm)
 
 	return review, comm, nil

templates/repo/diff/comment_form.tmpl

@@ -4,6 +4,7 @@
 	{{end}}
 	<form class="ui form {{if $.hidden}}hide comment-form comment-form-reply{{end}}" action="{{$.root.Issue.HTMLURL}}/files/reviews/comments" method="post">
 	{{$.root.CsrfTokenHtml}}
+		<input type="hidden" name="latest_commit_id" value="{{$.root.AfterCommitID}}"/>
 		<input type="hidden" name="side" value="{{if $.Side}}{{$.Side}}{{end}}">
 		<input type="hidden" name="line" value="{{if $.Line}}{{$.Line}}{{end}}">
 		<input type="hidden" name="path" value="{{if $.File}}{{$.File}}{{end}}">

templates/repo/diff/new_review.tmpl

@@ -7,6 +7,7 @@
 		<div class="ui clearing segment">
 			<form class="ui form" action="{{.Link}}/reviews/submit" method="post">
 			{{.CsrfTokenHtml}}
+			    <input type="hidden" name="commit_id" value="{{.AfterCommitID}}"/>
 				<i class="ui right floated link icon close"></i>
 				<div class="header">
 				{{$.i18n.Tr "repo.diff.review.header"}}

templates/repo/issue/view_content/pull.tmpl

@@ -13,6 +13,11 @@
 							{{else}}grey{{end}}">
 							<span class="octicon octicon-{{.Type.Icon}}"></span>
 						</span>
+						{{if .Stale}}
+						<span class="type-icon text grey">
+							<i class="octicon icon fa-hourglass-end"></i>
+						</span>
+						{{end}}
 						<a class="ui avatar image" href="{{.Reviewer.HomeLink}}">
 							<img src="{{.Reviewer.RelAvatarLink}}">
 						</a>

templates/repo/settings/protected_branch.tmpl

@@ -211,6 +211,14 @@
 							<p class="help">{{.i18n.Tr "repo.settings.block_rejected_reviews_desc"}}</p>
 						</div>
 					</div>					
+					<div class="field">
+						<div class="ui checkbox">
+							<input name="dismiss_stale_approvals" type="checkbox" {{if .Branch.DismissStaleApprovals}}checked{{end}}>
+							<label for="dismiss_stale_approvals">{{.i18n.Tr "repo.settings.dismiss_stale_approvals"}}</label>
+							<p class="help">{{.i18n.Tr "repo.settings.dismiss_stale_approvals_desc"}}</p>
+						</div>
+					</div>
+
 				</div>
 
 				<div class="ui divider"></div>