Always defer *sql.Rows.Close and consult with Err (#844)

* Always defer *sql.Rows.Close and consult with Err

database/sql.Rows.Next() makes sure to call Close only after exhausting
result rows which would NOT happen when returning early from a bad Scan.
Close being idempotent makes it a great candidate to get always deferred
regardless of what happens later on the result set.

This change also makes sure call Err() after exhausting Next() and
propagate non-nil results from it as the documentation advises.

Closes #764

Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org>

* Override named result parameters in last returns

Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org>

* Do the same over new changes that got merged

Signed-off-by: Kiril Vladimiroff <kiril@vladimiroff.org>

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/federationsender/storage/postgres/joined_hosts_table.go b/federationsender/storage/postgres/joined_hosts_table.go
index bd580e3b..e5c30a01 100644
--- a/federationsender/storage/postgres/joined_hosts_table.go
+++ b/federationsender/storage/postgres/joined_hosts_table.go
@@ -132,5 +132,5 @@ func joinedHostsFromStmt(
 		})
 	}
 
-	return result, nil
+	return result, rows.Err()
 }