net/http: Request Body error should not be ignored.

Fixes #7521.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/76320043

diff --git a/src/pkg/net/http/requestwrite_test.go b/src/pkg/net/http/requestwrite_test.go
index 561eea28e5ab6059eabf34f088c84f9276688ce1..dc0e204cac98c7c2d86686ff76c438604513e8dc 100644 (file)
--- a/src/pkg/net/http/requestwrite_test.go
+++ b/src/pkg/net/http/requestwrite_test.go
@@ -310,6 +310,46 @@ var reqWriteTests = []reqWriteTest{
                WantError: errors.New("http: Request.ContentLength=5 with nil Body"),
        },
 
+       // Request with a 0 ContentLength and a body with 1 byte content and an error.
+       {
+               Req: Request{
+                       Method:        "POST",
+                       URL:           mustParseURL("/"),
+                       Host:          "example.com",
+                       ProtoMajor:    1,
+                       ProtoMinor:    1,
+                       ContentLength: 0, // as if unset by user
+               },
+
+               Body: func() io.ReadCloser {
+                       err := errors.New("Custom reader error")
+                       errReader := &errorReader{err}
+                       return ioutil.NopCloser(io.MultiReader(strings.NewReader("x"), errReader))
+               },
+
+               WantError: errors.New("Custom reader error"),
+       },
+
+       // Request with a 0 ContentLength and a body without content and an error.
+       {
+               Req: Request{
+                       Method:        "POST",
+                       URL:           mustParseURL("/"),
+                       Host:          "example.com",
+                       ProtoMajor:    1,
+                       ProtoMinor:    1,
+                       ContentLength: 0, // as if unset by user
+               },
+
+               Body: func() io.ReadCloser {
+                       err := errors.New("Custom reader error")
+                       errReader := &errorReader{err}
+                       return ioutil.NopCloser(errReader)
+               },
+
+               WantError: errors.New("Custom reader error"),
+       },
+
        // Verify that DumpRequest preserves the HTTP version number, doesn't add a Host,
        // and doesn't add a User-Agent.
        {

diff --git a/src/pkg/net/http/transfer.go b/src/pkg/net/http/transfer.go
index 2eec9d9abc4788357d636a56d6b5deba79ae6f6b..d509e14419acfbf269c74a52cde67c278bce6b4f 100644 (file)
--- a/src/pkg/net/http/transfer.go
+++ b/src/pkg/net/http/transfer.go
@@ -17,6 +17,14 @@ import (
        "sync"
 )
 
+type errorReader struct {
+       err error
+}
+
+func (r *errorReader) Read(p []byte) (n int, err error) {
+       return 0, r.err
+}
+
 // transferWriter inspects the fields of a user-supplied Request or Response,
 // sanitizes them without changing the user object and provides methods for
 // writing the respective header, body and trailer in wire format.
@@ -53,8 +61,11 @@ func newTransferWriter(r interface{}) (t *transferWriter, err error) {
                        if t.ContentLength == 0 {
                                // Test to see if it's actually zero or just unset.
                                var buf [1]byte
-                               n, _ := io.ReadFull(t.Body, buf[:])
-                               if n == 1 {
+                               n, rerr := io.ReadFull(t.Body, buf[:])
+                               if rerr != nil && rerr != io.EOF {
+                                       t.ContentLength = -1
+                                       t.Body = &errorReader{rerr}
+                               } else if n == 1 {
                                        // Oh, guess there is data in this Body Reader after all.
                                        // The ContentLength field just wasn't set.
                                        // Stich the Body back together again, re-attaching our