diff options
| -rw-r--r-- | src/mime/multipart/formdata_test.go | 36 | ||||
| -rw-r--r-- | src/mime/multipart/multipart.go | 20 |
2 files changed, 55 insertions, 1 deletions
diff --git a/src/mime/multipart/formdata_test.go b/src/mime/multipart/formdata_test.go index 6e2388bafe..1deca0b94d 100644 --- a/src/mime/multipart/formdata_test.go +++ b/src/mime/multipart/formdata_test.go @@ -88,3 +88,39 @@ Content-Disposition: form-data; name="textb" ` + textbValue + ` --MyBoundary-- ` + +func TestReadForm_NoReadAfterEOF(t *testing.T) { + maxMemory := int64(32) << 20 + boundary := `---------------------------8d345eef0d38dc9` + body := ` +-----------------------------8d345eef0d38dc9 +Content-Disposition: form-data; name="version" + +171 +-----------------------------8d345eef0d38dc9--` + + mr := NewReader(&failOnReadAfterErrorReader{t: t, r: strings.NewReader(body)}, boundary) + + f, err := mr.ReadForm(maxMemory) + if err != nil { + t.Fatal(err) + } + t.Logf("Got: %#v", f) +} + +// failOnReadAfterErrorReader is an io.Reader wrapping r. +// It fails t if any Read is called after a failing Read. +type failOnReadAfterErrorReader struct { + t *testing.T + r io.Reader + sawErr error +} + +func (r *failOnReadAfterErrorReader) Read(p []byte) (n int, err error) { + if r.sawErr != nil { + r.t.Fatalf("unexpected Read on Reader after previous read saw error %v", r.sawErr) + } + n, err = r.r.Read(p) + r.sawErr = err + return +} diff --git a/src/mime/multipart/multipart.go b/src/mime/multipart/multipart.go index 3b746a5e15..c21c3fc70e 100644 --- a/src/mime/multipart/multipart.go +++ b/src/mime/multipart/multipart.go @@ -96,7 +96,7 @@ func (p *Part) parseContentDisposition() { func NewReader(r io.Reader, boundary string) *Reader { b := []byte("\r\n--" + boundary + "--") return &Reader{ - bufReader: bufio.NewReaderSize(r, peekBufferSize), + bufReader: bufio.NewReaderSize(&stickyErrorReader{r: r}, peekBufferSize), nl: b[:2], nlDashBoundary: b[:len(b)-2], dashBoundaryDash: b[2:], @@ -104,6 +104,24 @@ func NewReader(r io.Reader, boundary string) *Reader { } } +// stickyErrorReader is an io.Reader which never calls Read on its +// underlying Reader once an error has been seen. (the io.Reader +// interface's contract promises nothing about the return values of +// Read calls after an error, yet this package does do multiple Reads +// after error) +type stickyErrorReader struct { + r io.Reader + err error +} + +func (r *stickyErrorReader) Read(p []byte) (n int, _ error) { + if r.err != nil { + return 0, r.err + } + n, r.err = r.r.Read(p) + return n, r.err +} + func newPart(mr *Reader) (*Part, error) { bp := &Part{ Header: make(map[string][]string), |