code review 84750043: net: drop unnecessary nested error notifications

net: drop unnecessary nested error notifications

Before fixing some weirdnesses on error notifications of the net
package, we need to drop unnecessary nested error notifications like
&net.OpError{Err: &os.SyscallError{Err: syscall.Errno} because this
type of notifications doesn't conform with net.Error interface and
makes things confuse.

We will provide a few limited types of error notifications on network
connection setup, teardown and IO operation paths like the following:
- io.EOF
- syscall.Errno
- &net.OpError{Err: syscall.Errno}
- &net.OpError{Err: &errors.errorString{}}
- &net.OpError{Err: &os.SyscallError{Err: syscall.Errno}}

Update issue 4856
Update issue 7708

[mikio, 2014-04-05 03:21:55]

Hello iant@golang.org (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
http://code.google.com/p/go

[brainman, 2014-04-06 02:37:32]

https://codereview.appspot.com/84750043/diff/80001/src/pkg/net/lookup_windows.go
File src/pkg/net/lookup_windows.go (left):

https://codereview.appspot.com/84750043/diff/80001/src/pkg/net/lookup_windows...
src/pkg/net/lookup_windows.go:22: return 0, os.NewSyscallError("GetProtoByName",
err)
How is that line change relates to "drop unnecessary nested error
notifications"? (same everywhere in windows files) Specifying which system call
failed will actually help users to determine what the problem is. Why deny them
that luxury?

[bradfitz, 2014-04-06 02:38:59]

So many changes in these parts at this stage makes me nervous, especially
without new (or old) tests.

[iant, 2014-04-07 17:20:09]

I agree.

Ian

On Sat, Apr 5, 2014 at 7:38 PM,  <bradfitz@golang.org> wrote:
> So many changes in these parts at this stage makes me nervous,
> especially without new (or old) tests.
>
>
> https://codereview.appspot.com/84750043/

[mikio, 2014-04-10 00:48:15]

sure, just sent CL 85630044.

On 2014/04/07 17:20:09, iant wrote:
> I agree.
> 
> Ian
> 
> On Sat, Apr 5, 2014 at 7:38 PM,  <mailto:bradfitz@golang.org> wrote:
> > So many changes in these parts at this stage makes me nervous,
> > especially without new (or old) tests.
> >
> >
> > https://codereview.appspot.com/84750043/

[mikio, 2014-04-10 00:51:44]

https://codereview.appspot.com/84750043/diff/80001/src/pkg/net/lookup_windows.go
File src/pkg/net/lookup_windows.go (left):

https://codereview.appspot.com/84750043/diff/80001/src/pkg/net/lookup_windows...
src/pkg/net/lookup_windows.go:22: return 0, os.NewSyscallError("GetProtoByName",
err)
On 2014/04/06 02:37:32, brainman wrote:
> How is that line change relates to "drop unnecessary nested error
> notifications"? (same everywhere in windows files) Specifying which system
call
> failed will actually help users to determine what the problem is. Why deny
them
> that luxury?

Hm, if you prefer to preserve such information, will do so.

[rsc, 2014-04-17 02:59:28]

R=close

I'm sorry, but we're about to cut the 1.3 beta, and I don't want to make this
change after that. If it has been like this since Go 1.0 it can probably stand
to be like this until Go 1.4. The actual thing you're doing sounds completely
reaonable and good, just not right now. Running 'hg mail' once 1.3 is out will
reopen the CL.

Thanks.

[mikio, 2014-04-22 00:31:20]

*** Abandoned ***