diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 77f2ab053..0fdaf855d 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -56,12 +56,13 @@ func expiredMigration(x *xorm.Engine) error {
 
 func prepareToCommitComments(x *xorm.Engine) error {
 
-	sql := `ALTER TABLE comment MODIFY commit_id VARCHAR(50) DEFAULT NULL`
+	sql := `ALTER TABLE comment MODIFY commit_id VARCHAR(50) NULL DEFAULT NULL`
 	_, err := x.Exec(sql)
 	if err != nil {
 		return err
 	}
-	sql = `ALTER TABLE comment MODIFY line VARCHAR(50) DEFAULT NULL;`
+
+	sql = `ALTER TABLE comment MODIFY line VARCHAR(50) NULL DEFAULT NULL;`
 	_, err = x.Exec(sql)
 	if err != nil {
 		return err
diff --git a/modules/mailer/mail.go b/modules/mailer/mail.go
index 004feedb8..7a345e077 100644
--- a/modules/mailer/mail.go
+++ b/modules/mailer/mail.go
@@ -222,6 +222,7 @@ func SendIssueMentionMail(r macaron.Render, u, owner *models.User,
 	data := GetMailTmplData(nil)
 	data["IssueLink"] = fmt.Sprintf("%s/%s/issues/%d", owner.Name, repo.Name, issue.Index)
 	data["Subject"] = subject
+	data["ActUserName"] = u.Name
 
 	body, err := r.HTMLString(string(NOTIFY_MENTION), data)
 	if err != nil {
@@ -246,6 +247,7 @@ func SendCommentMentionMail(r macaron.Render, u, owner *models.User,
 	data := GetMailTmplData(nil)
 	data["IssueLink"] = fmt.Sprintf("%s/%s/commit/%s", owner.Name, repo.Name, comment.CommitId)
 	data["Subject"] = subject
+	data["ActUserName"] = u.Name
 
 	body, err := r.HTMLString(string(NOTIFY_MENTION), data)
 	if err != nil {