Prevent merge messages from being sorted to the top of email chains (#18566)

services/mailer/mail.go

@@ -14,6 +14,7 @@ import (
 	"strconv"
 	"strings"
 	texttmpl "text/template"
+	"time"
 
 	"code.gitea.io/gitea/models"
 	repo_model "code.gitea.io/gitea/models/repo"
@@ -297,13 +298,15 @@ func composeIssueCommentMessages(ctx *mailCommentContext, lang string, recipient
 	}
 
 	// Make sure to compose independent messages to avoid leaking user emails
+	msgID := createReference(ctx.Issue, ctx.Comment, ctx.ActionType)
+	reference := createReference(ctx.Issue, nil, models.ActionType(0))
+
 	msgs := make([]*Message, 0, len(recipients))
 	for _, recipient := range recipients {
 		msg := NewMessageFrom([]string{recipient.Email}, ctx.Doer.DisplayName(), setting.MailService.FromEmail, subject, mailBody.String())
 		msg.Info = fmt.Sprintf("Subject: %s, %s", subject, info)
 
-		msg.SetHeader("Message-ID", "<"+createReference(ctx.Issue, ctx.Comment)+">")
-		reference := createReference(ctx.Issue, nil)
+		msg.SetHeader("Message-ID", "<"+msgID+">")
 		msg.SetHeader("In-Reply-To", "<"+reference+">")
 		msg.SetHeader("References", "<"+reference+">")
 
@@ -317,7 +320,7 @@ func composeIssueCommentMessages(ctx *mailCommentContext, lang string, recipient
 	return msgs, nil
 }
 
-func createReference(issue *models.Issue, comment *models.Comment) string {
+func createReference(issue *models.Issue, comment *models.Comment, actionType models.ActionType) string {
 	var path string
 	if issue.IsPull {
 		path = "pulls"
@@ -328,6 +331,17 @@ func createReference(issue *models.Issue, comment *models.Comment) string {
 	var extra string
 	if comment != nil {
 		extra = fmt.Sprintf("/comment/%d", comment.ID)
+	} else {
+		switch actionType {
+		case models.ActionCloseIssue, models.ActionClosePullRequest:
+			extra = fmt.Sprintf("/close/%d", time.Now().UnixNano()/1e6)
+		case models.ActionReopenIssue, models.ActionReopenPullRequest:
+			extra = fmt.Sprintf("/reopen/%d", time.Now().UnixNano()/1e6)
+		case models.ActionMergePullRequest:
+			extra = fmt.Sprintf("/merge/%d", time.Now().UnixNano()/1e6)
+		case models.ActionPullRequestReadyForReview:
+			extra = fmt.Sprintf("/ready/%d", time.Now().UnixNano()/1e6)
+		}
 	}
 
 	return fmt.Sprintf("%s/%s/%d%s@%s", issue.Repo.FullName(), path, issue.Index, extra, setting.Domain)

services/mailer/mail_test.go

@@ -6,7 +6,9 @@ package mailer
 
 import (
 	"bytes"
+	"fmt"
 	"html/template"
+	"strings"
 	"testing"
 	texttmpl "text/template"
 
@@ -15,7 +17,6 @@ import (
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/setting"
-
 	"github.com/stretchr/testify/assert"
 )
 
@@ -236,3 +237,115 @@ func TestGenerateAdditionalHeaders(t *testing.T) {
 		}
 	}
 }
+
+func Test_createReference(t *testing.T) {
+	_, _, issue, comment := prepareMailerTest(t)
+	_, _, pullIssue, _ := prepareMailerTest(t)
+	pullIssue.IsPull = true
+
+	type args struct {
+		issue      *models.Issue
+		comment    *models.Comment
+		actionType models.ActionType
+	}
+	tests := []struct {
+		name   string
+		args   args
+		prefix string
+		suffix string
+	}{
+		{
+			name: "Open Issue",
+			args: args{
+				issue:      issue,
+				actionType: models.ActionCreateIssue,
+			},
+			prefix: fmt.Sprintf("%s/issues/%d@%s", issue.Repo.FullName(), issue.Index, setting.Domain),
+		},
+		{
+			name: "Open Pull",
+			args: args{
+				issue:      pullIssue,
+				actionType: models.ActionCreatePullRequest,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d@%s", issue.Repo.FullName(), issue.Index, setting.Domain),
+		},
+		{
+			name: "Comment Issue",
+			args: args{
+				issue:      issue,
+				comment:    comment,
+				actionType: models.ActionCommentIssue,
+			},
+			prefix: fmt.Sprintf("%s/issues/%d/comment/%d@%s", issue.Repo.FullName(), issue.Index, comment.ID, setting.Domain),
+		},
+		{
+			name: "Comment Pull",
+			args: args{
+				issue:      pullIssue,
+				comment:    comment,
+				actionType: models.ActionCommentPull,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d/comment/%d@%s", issue.Repo.FullName(), issue.Index, comment.ID, setting.Domain),
+		},
+		{
+			name: "Close Issue",
+			args: args{
+				issue:      issue,
+				actionType: models.ActionCloseIssue,
+			},
+			prefix: fmt.Sprintf("%s/issues/%d/close/", issue.Repo.FullName(), issue.Index),
+		},
+		{
+			name: "Close Pull",
+			args: args{
+				issue:      pullIssue,
+				actionType: models.ActionClosePullRequest,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d/close/", issue.Repo.FullName(), issue.Index),
+		},
+		{
+			name: "Reopen Issue",
+			args: args{
+				issue:      issue,
+				actionType: models.ActionReopenIssue,
+			},
+			prefix: fmt.Sprintf("%s/issues/%d/reopen/", issue.Repo.FullName(), issue.Index),
+		},
+		{
+			name: "Reopen Pull",
+			args: args{
+				issue:      pullIssue,
+				actionType: models.ActionReopenPullRequest,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d/reopen/", issue.Repo.FullName(), issue.Index),
+		},
+		{
+			name: "Merge Pull",
+			args: args{
+				issue:      pullIssue,
+				actionType: models.ActionMergePullRequest,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d/merge/", issue.Repo.FullName(), issue.Index),
+		},
+		{
+			name: "Ready Pull",
+			args: args{
+				issue:      pullIssue,
+				actionType: models.ActionPullRequestReadyForReview,
+			},
+			prefix: fmt.Sprintf("%s/pulls/%d/ready/", issue.Repo.FullName(), issue.Index),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := createReference(tt.args.issue, tt.args.comment, tt.args.actionType)
+			if !strings.HasPrefix(got, tt.prefix) {
+				t.Errorf("createReference() = %v, want %v", got, tt.prefix)
+			}
+			if !strings.HasSuffix(got, tt.suffix) {
+				t.Errorf("createReference() = %v, want %v", got, tt.prefix)
+			}
+		})
+	}
+}