Fix database write context interleaving bug (#3822)

* UpdateIssueUsersByMentions was calling database write operations while
a transaction session was in progress. MailParticipants was failing
silently because of the SQLITE_LOCKED error. Make sure failures in
MailParticipants enter the log, and pass on the transaction context.

issue: let caller pass in database context, and use it
issue_comment: obtain database context to pass to UpdateIssueMentions
issue_comment: log any error from call to MailParticipants
issue_mail: pass on database context to UpdateIssueMentions

* issue: forgot debug statement

1 files changed, 7 insertions, 7 deletions

diff --git a/models/issue.go b/models/issue.go
index 6dfb4717..e14b4462 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -1026,7 +1026,7 @@ func GetIssueUserPairsByMode(uid, rid int64, isClosed bool, page, filterMode int
 
 // UpdateIssueMentions extracts mentioned people from content and
 // updates issue-user relations for them.
-func UpdateIssueMentions(issueID int64, mentions []string) error {
+func UpdateIssueMentions(e Engine, issueID int64, mentions []string) error {
 	if len(mentions) == 0 {
 		return nil
 	}
@@ -1036,7 +1036,7 @@ func UpdateIssueMentions(issueID int64, mentions []string) error {
 	}
 	users := make([]*User, 0, len(mentions))
 
-	if err := x.In("lower_name", mentions).Asc("lower_name").Find(&users); err != nil {
+	if err := e.In("lower_name", mentions).Asc("lower_name").Find(&users); err != nil {
 		return fmt.Errorf("find mentioned users: %v", err)
 	}
 
@@ -1060,7 +1060,7 @@ func UpdateIssueMentions(issueID int64, mentions []string) error {
 		ids = append(ids, memberIDs...)
 	}
 
-	if err := UpdateIssueUsersByMentions(issueID, ids); err != nil {
+	if err := UpdateIssueUsersByMentions(e, issueID, ids); err != nil {
 		return fmt.Errorf("UpdateIssueUsersByMentions: %v", err)
 	}
 
@@ -1293,22 +1293,22 @@ func UpdateIssueUserByRead(uid, issueID int64) error {
 }
 
 // UpdateIssueUsersByMentions updates issue-user pairs by mentioning.
-func UpdateIssueUsersByMentions(issueID int64, uids []int64) error {
+func UpdateIssueUsersByMentions(e Engine, issueID int64, uids []int64) error {
 	for _, uid := range uids {
 		iu := &IssueUser{
 			UID:     uid,
 			IssueID: issueID,
 		}
-		has, err := x.Get(iu)
+		has, err := e.Get(iu)
 		if err != nil {
 			return err
 		}
 
 		iu.IsMentioned = true
 		if has {
-			_, err = x.Id(iu.ID).AllCols().Update(iu)
+			_, err = e.Id(iu.ID).AllCols().Update(iu)
 		} else {
-			_, err = x.Insert(iu)
+			_, err = e.Insert(iu)
 		}
 		if err != nil {
 			return err