selfupdate: improve error handling

internal/selfupdate/download.go

@@ -80,9 +80,12 @@ func extractToFile(buf []byte, filename, target string, printf func(string, ...i
 		return err
 	}
 	if err = newFile.Sync(); err != nil {
+		_ = newFile.Close()
+		_ = os.Remove(newFile.Name())
 		return err
 	}
 	if err = newFile.Close(); err != nil {
+		_ = os.Remove(newFile.Name())
 		return err
 	}
 

internal/selfupdate/github.go

@@ -87,6 +87,7 @@ func GitHubLatestRelease(ctx context.Context, owner, repo string) (Release, erro
 			var msg githubError
 			jerr := json.NewDecoder(res.Body).Decode(&msg)
 			if jerr == nil {
+				_ = res.Body.Close()
 				return Release{}, fmt.Errorf("unexpected status %v (%v) returned, message:\n  %v", res.StatusCode, res.Status, msg.Message)
 			}
 		}
@@ -137,6 +138,7 @@ func getGithubData(ctx context.Context, url string) ([]byte, error) {
 	}
 
 	if res.StatusCode != http.StatusOK {
+		_ = res.Body.Close()
 		return nil, fmt.Errorf("unexpected status %v (%v) returned", res.StatusCode, res.Status)
 	}