consider empty oldstate

Author: davegarthsimpson

Diff for: arduino-ide-extension/src/browser/boards/boards-service-provider.ts

@@ -143,9 +143,12 @@ export class BoardsServiceProvider implements FrontendApplicationContribution {
     const lastSelectionOnUpload = this.lastBoardsConfigOnUpload;
     this.setLastBoardsConfigOnUpload(undefined);
 
-    const appearedPorts = newPorts.filter((newPort: Port) =>
-      oldPorts.every((oldPort: Port) => !Port.sameAs(newPort, oldPort))
-    );
+    const appearedPorts =
+      oldPorts.length > 0
+        ? newPorts.filter((newPort: Port) =>
+            oldPorts.every((oldPort: Port) => !Port.sameAs(newPort, oldPort))
+          )
+        : newPorts;
 
     if (appearedPorts.length > 0) {
       const boardOnAppearedPort = newBoards.find((board: Board) =>