matrix-org/dendrite: appservice/query/query.go; 44 LoC

Found a possible issue in [matrix-org/dendrite](https://www.github.com/matrix-org/dendrite) at [appservice/query/query.go](https://github.com/matrix-org/dendrite/blob/a85051ca9de82756a94f1ea6870de9bd140a6b20/appservice/query/query.go#L124-L167)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first issue it finds, so please do not limit your consideration to the contents of the below message.

> range-loop variable appservice used in defer or goroutine at line 143

[Click here to see the code in its original context.](https://github.com/matrix-org/dendrite/blob/a85051ca9de82756a94f1ea6870de9bd140a6b20/appservice/query/query.go#L124-L167)

Click here to show the 44 line(s) of Go which triggered the analyzer.

```go
for _, appservice := range a.Cfg.Derived.ApplicationServices {
if appservice.URL != "" && appservice.IsInterestedInUserID(request.UserID) {
// The full path to the rooms API, includes hs token
URL, err := url.Parse(appservice.URL + userIDExistsPath)
URL.Path += request.UserID
apiURL := URL.String() + "?access_token=" + appservice.HSToken

// Send a request to each application service. If one responds that it has
// created the user, immediately return.
req, err := http.NewRequest(http.MethodGet, apiURL, nil)
if err != nil {
return err
}
resp, err := a.HTTPClient.Do(req.WithContext(ctx))
if resp != nil {
defer func() {
err = resp.Body.Close()
if err != nil {
log.WithFields(log.Fields{
"appservice_id": appservice.ID,
"status_code": resp.StatusCode,
}).Error("Unable to close application service response body")
}
}()
}
if err != nil {
log.WithFields(log.Fields{
"appservice_id": appservice.ID,
}).WithError(err).Error("issue querying user ID on application service")
return err
}
if resp.StatusCode == http.StatusOK {
// StatusOK received from appservice. User ID exists
response.UserIDExists = true
return nil
}

// Log non OK
log.WithFields(log.Fields{
"appservice_id": appservice.ID,
"status_code": resp.StatusCode,
}).Warn("application service responded with non-OK status code")
}
}

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: a85051ca9de82756a94f1ea6870de9bd140a6b20