net/http/httputil: DumpRequest() / DumpRequestOut() non-functional for SSL URLs

[gopherbot]

by jason.swank:

What steps will reproduce the problem? Invoke httputil.DumpRequestOut() with a request
to an SSL URL

What is the expected output? []byte, err

What do you see instead?

sync.runtime_Semacquire(0x18913cb8, 0x18913cb8)
        /home/jswank/go/src/pkg/runtime/zsema_386.c:146 +0x29
sync.(*Cond).Wait(0x18839dc4, 0x8096506)
        /home/jswank/go/src/pkg/sync/cond.go:67 +0xa8
io.(*pipe).write(0x18839d80, 0x18934400, 0x7, 0x400, 0x0, ...)
        /home/jswank/go/src/pkg/io/pipe.go:90 +0x133
io.(*PipeWriter).Write(0x18853410, 0x18934400, 0x7, 0x400, 0x80547d2, ...)
        /home/jswank/go/src/pkg/io/pipe.go:157 +0x41
io.(*multiWriter).Write(0x18837360, 0x18934400, 0x7, 0x400, 0x18934400, ...)
        /home/jswank/go/src/pkg/io/multi.go:40 +0x7e
net/http/httputil.(*dumpConn).Write(0x18837370, 0x18934400, 0x7, 0x400, 0x2, ...)
        /home/jswank/go/src/pkg/net/http/httputil/chunked.go:0 +0x4f
crypto/tls.(*Conn).writeRecord(0x18877000, 0x15, 0x18877168, 0x2, 0x10, ...)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:636 +0x1b7
----- stack segment boundary -----
crypto/tls.(*Conn).sendAlertLocked(0x18877000, 0x416, 0x400, 0x188cd400)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:598 +0xb8
crypto/tls.(*Conn).sendAlert(0x18877000, 0x1893a716, 0x0, 0x0)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:611 +0x6d
crypto/tls.(*Conn).readRecord(0x18877000, 0x18837316, 0x18934400, 0x59)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:496 +0x2a2
crypto/tls.(*Conn).readHandshake(0x18877000, 0x1891ea16, 0x1891ea74)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:668 +0x8f
crypto/tls.(*Conn).clientHandshake(0x18877000, 0x0, 0x0)
        /home/jswank/go/src/pkg/crypto/tls/handshake_client.go:51 +0x59f
crypto/tls.(*Conn).Handshake(0x18877000, 0x0, 0x0)
        /home/jswank/go/src/pkg/crypto/tls/conn.go:808 +0xc3
net/http.(*Transport).getConn(0x18834660, 0x1884ca60, 0x1884ca60, 0x0)
        /home/jswank/go/src/pkg/net/http/transport.go:367 +0x398
net/http.(*Transport).RoundTrip(0x18834660, 0x188571c0, 0x18853400, 0x0, 0x0, ...)
        /home/jswank/go/src/pkg/net/http/transport.go:153 +0x23b
net/http/httputil.DumpRequestOut(0x188571c0, 0x0, 0xbfba2b20, 0x18)
        /home/jswank/go/src/pkg/net/http/httputil/dump.go:82 +0x1de
main.main()
        /home/jswank/repos/golangfu.com/examples/httputil-test.go:25 +0x1fb
created by _rt0_386
        /home/jswank/go/src/pkg/runtime/asm_386.s:80 +0xc0


Which compiler are you using (5g, 6g, 8g, gccgo)?

Which operating system are you using? Linux x86

Which revision are you using?  (hg identify)
Both "weekly-2012-02-22" and "tip" return this error.

Please provide any additional information below. Attached example program.

Attachments:

1. httputil-test.go (913 bytes)

[robpike]

Comment 1:

Labels changed: added priority-go1, go1-must, removed priority-triage.

Status changed to Accepted.

[robpike]

Comment 2:

Owner changed to [email protected].

[dsymonds]

Comment 3:

Labels changed: added packagebug.

Owner changed to @bradfitz.

[bradfitz]

Comment 4:

http://golang.org/cl/5709050

[bradfitz]

Comment 5:

This issue was closed by revision 1b1039a.

Status changed to Fixed.

[rsc]

Comment 6:

I don't believe the fix is safe.  Reopening so we don't forget.

Status changed to Accepted.

[rsc]

Comment 7:

*** Submitted as
http://code.google.com/p/go/source/detail?r=3cfa14662422 ***
net/http/httputil: make https DumpRequestOut less racy
It's still racy in that it mutates req.Body, though.  *shrug*
R=golang-dev, rsc
CC=golang-dev
http://golang.org/cl/5709054

Status changed to Fixed.

[gopherbot]

Comment 8 by pkorotkov:

Could you please specify what's wrong with the current implementation and why you can't
exclude the race? Perhaps, it's good idea to make a relevant note the documentation
about possible race in some cases.

[rsc]

Comment 9:

There's nothing wrong with the current implementation: the second CL
fixed the race.