Retry create issue to cope with duplicate keys (#7898)

* Retry create issue to cope with duplicate keys

* Use  .SetExpr().Where().Insert()

1 files changed, 23 insertions, 29 deletions

diff --git a/models/issue.go b/models/issue.go
index fc74c73162..b849f97bd4 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -5,7 +5,6 @@
 package models
 
 import (
-	"errors"
 	"fmt"
 	"path"
 	"regexp"
@@ -74,6 +73,7 @@ var (
 
 const issueTasksRegexpStr = `(^\s*[-*]\s\[[\sx]\]\s.)|(\n\s*[-*]\s\[[\sx]\]\s.)`
 const issueTasksDoneRegexpStr = `(^\s*[-*]\s\[[x]\]\s.)|(\n\s*[-*]\s\[[x]\]\s.)`
+const issueMaxDupIndexAttempts = 3
 
 func init() {
 	issueTasksPat = regexp.MustCompile(issueTasksRegexpStr)
@@ -1031,36 +1031,9 @@ type NewIssueOptions struct {
 	IsPull      bool
 }
 
-// GetMaxIndexOfIssue returns the max index on issue
-func GetMaxIndexOfIssue(repoID int64) (int64, error) {
-	return getMaxIndexOfIssue(x, repoID)
-}
-
-func getMaxIndexOfIssue(e Engine, repoID int64) (int64, error) {
-	var (
-		maxIndex int64
-		has      bool
-		err      error
-	)
-
-	has, err = e.SQL("SELECT COALESCE((SELECT MAX(`index`) FROM issue WHERE repo_id = ?),0)", repoID).Get(&maxIndex)
-	if err != nil {
-		return 0, err
-	} else if !has {
-		return 0, errors.New("Retrieve Max index from issue failed")
-	}
-	return maxIndex, nil
-}
-
 func newIssue(e *xorm.Session, doer *User, opts NewIssueOptions) (err error) {
 	opts.Issue.Title = strings.TrimSpace(opts.Issue.Title)
 
-	maxIndex, err := getMaxIndexOfIssue(e, opts.Issue.RepoID)
-	if err != nil {
-		return err
-	}
-	opts.Issue.Index = maxIndex + 1
-
 	if opts.Issue.MilestoneID > 0 {
 		milestone, err := getMilestoneByRepoID(e, opts.Issue.RepoID, opts.Issue.MilestoneID)
 		if err != nil && !IsErrMilestoneNotExist(err) {
@@ -1109,10 +1082,31 @@ func newIssue(e *xorm.Session, doer *User, opts NewIssueOptions) (err error) {
 	}
 
 	// Milestone and assignee validation should happen before insert actual object.
-	if _, err = e.Insert(opts.Issue); err != nil {
+
+	// There's no good way to identify a duplicate key error in database/sql; brute force some retries
+	dupIndexAttempts := issueMaxDupIndexAttempts
+	for {
+		_, err := e.SetExpr("`index`", "coalesce(MAX(`index`),0)+1").
+			Where("repo_id=?", opts.Issue.RepoID).
+			Insert(opts.Issue)
+		if err == nil {
+			break
+		}
+
+		dupIndexAttempts--
+		if dupIndexAttempts <= 0 {
+			return err
+		}
+	}
+
+	inserted, err := getIssueByID(e, opts.Issue.ID)
+	if err != nil {
 		return err
 	}
 
+	// Patch Index with the value calculated by the database
+	opts.Issue.Index = inserted.Index
+
 	if opts.Issue.MilestoneID > 0 {
 		if err = changeMilestoneAssign(e, doer, opts.Issue, -1); err != nil {
 			return err