Add missing transaction rollbacks for SQL store (#9964)

* Add missing transaction rollbacks for SQL store

* Add `defer transaction.Rollback()` in SQL stores.

* abstract finalizeTransaction

store/sqlstore/utils.go

@@ -5,8 +5,12 @@ package sqlstore
 
 import (
 	"bytes"
+	"database/sql"
 	"fmt"
 	"strconv"
+
+	"github.com/mattermost/gorp"
+	"github.com/mattermost/mattermost-server/mlog"
 )
 
 // Converts a list of strings into a list of query parameters and a named parameter map that can
@@ -26,3 +30,11 @@ func MapStringsToQueryParams(list []string, paramPrefix string) (string, map[str
 
 	return fmt.Sprintf("(%v)", keys.String()), params
 }
+
+// finalizeTransaction ensures a transaction is closed after use, rolling back if not already committed.
+func finalizeTransaction(transaction *gorp.Transaction) {
+	// Rollback returns sql.ErrTxDone if the transaction was already closed.
+	if err := transaction.Rollback(); err != nil && err != sql.ErrTxDone {
+		mlog.Error("Failed to rollback transaction", mlog.Err(err))
+	}
+}