From 80b50afe1ff7dffba2d305c37f4ee86c041e16ea Mon Sep 17 00:00:00 2001
From: guillep2k <18600385+guillep2k@users.noreply.github.com>
Date: Sat, 12 Oct 2019 02:31:12 -0300
Subject: [PATCH] Add check for empty set when dropping indexes during
 migration (#8475)

---
 models/migrations/migrations.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 00356ffac76..24aa7c57184 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -384,9 +384,11 @@ func dropTableColumns(sess *xorm.Session, tableName string, columnNames ...strin
 		}
 		for _, index := range res {
 			indexName := index["column_name"]
-			_, err := sess.Exec(fmt.Sprintf("DROP INDEX `%s` ON `%s`", indexName, tableName))
-			if err != nil {
-				return err
+			if len(indexName) > 0 {
+				_, err := sess.Exec(fmt.Sprintf("DROP INDEX `%s` ON `%s`", indexName, tableName))
+				if err != nil {
+					return err
+				}
 			}
 		}