diff options
Diffstat (limited to 'src/net/http/client.go')
| -rw-r--r-- | src/net/http/client.go | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/net/http/client.go b/src/net/http/client.go index 638ff500a4..3860d97d8f 100644 --- a/src/net/http/client.go +++ b/src/net/http/client.go @@ -269,7 +269,20 @@ func send(ireq *Request, rt RoundTripper, deadline time.Time) (resp *Response, d return nil, didTimeout, fmt.Errorf("http: RoundTripper implementation (%T) returned a nil *Response with a nil error", rt) } if resp.Body == nil { - return nil, didTimeout, fmt.Errorf("http: RoundTripper implementation (%T) returned a *Response with a nil Body", rt) + // The documentation on the Body field says “The http Client and Transport + // guarantee that Body is always non-nil, even on responses without a body + // or responses with a zero-length body.” Unfortunately, we didn't document + // that same constraint for arbitrary RoundTripper implementations, and + // RoundTripper implementations in the wild (mostly in tests) assume that + // they can use a nil Body to mean an empty one (similar to Request.Body). + // (See https://golang.org/issue/38095.) + // + // If the ContentLength allows the Body to be empty, fill in an empty one + // here to ensure that it is non-nil. + if resp.ContentLength > 0 && req.Method != "HEAD" { + return nil, didTimeout, fmt.Errorf("http: RoundTripper implementation (%T) returned a *Response with content length %d but a nil Body", rt, resp.ContentLength) + } + resp.Body = ioutil.NopCloser(strings.NewReader("")) } if !deadline.IsZero() { resp.Body = &cancelTimerBody{ |