Merge pull request #1486 from ydb-platform/fix-panic

* Fixed nil pointer dereference panic on failed `ydb.Open`

CHANGELOG.md

@@ -1,4 +1,5 @@
-*  Added ip discovery. Server can show own ip address and target hostname in the ListEndpoint message. These fields are used to bypass DNS resolving.
+* Fixed nil pointer dereference panic on failed `ydb.Open` 
+* Added ip discovery. Server can show own ip address and target hostname in the ListEndpoint message. These fields are used to bypass DNS resolving.
 
 ## v3.81.0
 * Added error ErrMessagesPutToInternalQueueBeforeError to topic writer

driver.go

@@ -274,7 +274,9 @@ func Open(ctx context.Context, dsn string, opts ...Option) (_ *Driver, _ error)
 	}()
 
 	if err = d.connect(ctx); err != nil {
-		_ = d.pool.Release(ctx)
+		if d.pool != nil {
+			_ = d.pool.Release(ctx)
+		}
 
 		return nil, xerrors.WithStackTrace(err)
 	}