Fix v85.go: Set UNIQUE constraint later (#6851)

Signed-off-by: Andrew Thornton <art27@cantab.net>

models/migrations/v85.go

@@ -24,7 +24,7 @@ func hashAppToken(x *xorm.Engine) error {
 		Name           string
 		Sha1           string
 		Token          string `xorm:"-"`
-		TokenHash      string `xorm:"UNIQUE"` // sha256 of token
+		TokenHash      string // sha256 of token - we will ensure UNIQUE later
 		TokenSalt      string
 		TokenLastEight string `xorm:"token_last_eight"`
 
@@ -74,7 +74,7 @@ func hashAppToken(x *xorm.Engine) error {
 		return err
 	}
 
-	if err := x.Sync2(new(AccessToken)); err != nil {
+	if err := sess.Sync2(new(AccessToken)); err != nil {
 		return fmt.Errorf("Sync2: %v", err)
 	}
 
@@ -130,6 +130,24 @@ func hashAppToken(x *xorm.Engine) error {
 	if err := dropTableColumns(sess, "access_token", "sha1"); err != nil {
 		return err
 	}
-	return sess.Commit()
-
+	if err := sess.Commit(); err != nil {
+		return err
+	}
+	return resyncHashAppTokenWithUniqueHash(x)
+}
+
+func resyncHashAppTokenWithUniqueHash(x *xorm.Engine) error {
+	// AccessToken see models/token.go
+	type AccessToken struct {
+		TokenHash string `xorm:"UNIQUE"` // sha256 of token - we will ensure UNIQUE later
+	}
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+	if err := sess.Sync2(new(AccessToken)); err != nil {
+		return fmt.Errorf("Sync2: %v", err)
+	}
+	return sess.Commit()
 }