Refactor self-reference check into separate function

Extract isSelfReference function to improve code organization and reusability

Co-authored-by: silverwind <115237+silverwind@users.noreply.github.com>

Author: Copilot

services/issue/commit.go

@@ -89,6 +89,24 @@ func issueAddTime(ctx context.Context, issue *issues_model.Issue, doer *user_mod
 	return err
 }
 
+// isSelfReference checks if a commit is the merge commit of the PR it references.
+// This prevents creating self-referencing timeline entries when a PR merge commit
+// contains a reference to its own PR number in the commit message.
+func isSelfReference(ctx context.Context, issue *issues_model.Issue, commitSHA string) bool {
+	if !issue.IsPull {
+		return false
+	}
+
+	if err := issue.LoadPullRequest(ctx); err != nil {
+		if !issues_model.IsErrPullRequestNotExist(err) {
+			log.Error("LoadPullRequest: %v", err)
+		}
+		return false
+	}
+
+	return issue.PullRequest.MergedCommitID == commitSHA
+}
+
 // getIssueFromRef returns the issue referenced by a ref. Returns a nil *Issue
 // if the provided ref references a non-existent issue.
 func getIssueFromRef(ctx context.Context, repo *repo_model.Repository, index int64) (*issues_model.Issue, error) {
@@ -159,15 +177,8 @@ func UpdateIssuesCommit(ctx context.Context, doer *user_model.User, repo *repo_m
 			}
 
 			// Skip self-references: if this commit is the merge commit of the PR it references
-			if refIssue.IsPull {
-				if err := refIssue.LoadPullRequest(ctx); err != nil {
-					if !issues_model.IsErrPullRequestNotExist(err) {
-						log.Error("LoadPullRequest: %v", err)
-					}
-				} else if refIssue.PullRequest.MergedCommitID == c.Sha1 {
-					// This is a self-reference (PR merge commit referencing its own PR), skip it
-					continue
-				}
+			if isSelfReference(ctx, refIssue, c.Sha1) {
+				continue
 			}
 
 			message := fmt.Sprintf(`<a href="%s/commit/%s">%s</a>`, html.EscapeString(repo.Link()), html.EscapeString(url.PathEscape(c.Sha1)), html.EscapeString(strings.SplitN(c.Message, "\n", 2)[0]))