code review 6139066: Emacs go-mode: fix Emacs freeze-up when copy/pasting fr...

Emacs go-mode: fix Emacs freeze-up when copy/pasting from string or comment.

Fixes issue 3509.
Fixes issue 2767.

[pebbe, 2012-05-01 19:54:47]

Hello golang-dev@googlegroups.com,

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

[Sameer Ajmani, 2012-05-01 23:56:24]

On 2012/05/01 19:54:47, pebbe wrote:
> Hello mailto:golang-dev@googlegroups.com,
> 
> I'd like you to review this change to
> https://code.google.com/p/go

I'm very glad to see this fixed. 

For the record, can you explain what this is doing and why this fixes the
issues?

[pebbe, 2012-05-02 00:46:05]

On 2012/05/01 23:56:24, Sameer Ajmani wrote:
> On 2012/05/01 19:54:47, pebbe wrote:
> > Hello mailto:golang-dev@googlegroups.com,
> > 
> > I'd like you to review this change to
> > https://code.google.com/p/go
> 
> I'm very glad to see this fixed. 
> 
> For the record, can you explain what this is doing and why this fixes the
> issues?

Actually, this doesn't fix the issue in XEmacs, only in GNU Emacs. (But my
version of XEmacs is nearly two years old.)

The Elisp command 'yank' that does pasting inserts text that is saved including
its text-properties. Some of those text-properties are removed before inserting.
Which properties are removed is controlled by the value of
'yank-excluded-properties'.

Go-mode froze up in some cases when yanking text with property "go-mode-cs" to a
location where this property shouldn't be, and then the function 'go-mode-cs'
would get stuck in an infinite loop.

I don't quite understand how the function 'go-mode-cs' works, and my feeling is
that, perhaps, it is there that this problem should be addressed, but I don't
know how. 

So, adding "go-mode-cs" (the text property, not the function) to
'yank-excluded-properties' solves it "externally".

Please note:

Only tested with GNU Emacs 23.3.2. The docstring for 'yank-excluded-propertie'
states:

"This variable was introduced, or its default value was changed, in
version 22.1 of Emacs."

I have no idea if this fix works in versions of Emacs before 22.1.

Also note: XEmacs suffers from the same problem, and this fix does not work in
XEmacs. At least, not in version 21.4.22.

So, there is still need for a proper fix in the function 'go-mode-cs' itself,
and my patch should probably not be used.

[pebbe, 2012-05-02 10:49:16]

In the previous message, where I wrote 'go-mode-cs' function, it should be
'go-mode-font-lock-cs' function.

[pebbe, 2012-05-02 13:02:27]

Hello golang-dev@googlegroups.com, sameer@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[pebbe, 2012-05-02 13:05:35]

On 2012/05/02 13:02:27, pebbe wrote:
> Hello mailto:golang-dev@googlegroups.com, mailto:sameer@golang.org (cc:
> mailto:golang-dev@googlegroups.com),
> 
> Please take another look.

This patch (Patch Set 3) works in both GNU Emacs and XEmacs.

[Sameer Ajmani, 2012-05-07 14:11:52]

On 2012/05/02 13:05:35, pebbe wrote:
> On 2012/05/02 13:02:27, pebbe wrote:
> > Hello mailto:golang-dev@googlegroups.com, mailto:sameer@golang.org (cc:
> > mailto:golang-dev@googlegroups.com),
> > 
> > Please take another look.
> 
> This patch (Patch Set 3) works in both GNU Emacs and XEmacs.

Hi, since this is your first submission, please sign the CLA per the
instructions at:
  http://golang.org/doc/contribute.html#copyright
I'll take care of updating CONTRIBUTORS and AUTHORS for you.

[Sameer Ajmani, 2012-05-21 22:56:49]

ping Peter : I'd like to submit your patches, but we need you to sign the
CLA first. Please see the instructions in my previous email.
On May 7, 2012 10:11 AM, <sameer@golang.org> wrote:

> On 2012/05/02 13:05:35, pebbe wrote:
>
>> On 2012/05/02 13:02:27, pebbe wrote:
>> > Hello mailto:golang-dev@**googlegroups.com<golang-dev@googlegroups.com>,
>> mailto:sameer@golang.org
>>
> (cc:
>
>> > mailto:golang-dev@**googlegroups.com <golang-dev@googlegroups.com>),
>> >
>> > Please take another look.
>>
>
>  This patch (Patch Set 3) works in both GNU Emacs and XEmacs.
>>
>
> Hi, since this is your first submission, please sign the CLA per the
> instructions at:
> 
http://golang.org/doc/**contribute.html#copyright<http://golang.org/doc/contr...
> I'll take care of updating CONTRIBUTORS and AUTHORS for you.
>
>
http://codereview.appspot.com/**6139066/<http://codereview.appspot.com/6139066/>
>

[pebbe, 2012-05-22 08:29:51]

Sameer Ajmani schreef op de 21e dag van de bloeimaand van het jaar 2012:

> ping Peter : I'd like to submit your patches, but we need you to sign the
> CLA first. Please see the instructions in my previous email.

I did sign it, the day I got your previous mail. Did something 
go wrong? I didn't get an error message. Should I try signing 
again?





-- 
Peter

[Sameer Ajmani, 2012-05-22 13:16:58]

Ah, I must have missed it. I'll follow up today.
On May 22, 2012 4:29 AM, "Peter Kleiweg" <pkleiweg@xs4all.nl> wrote:

> Sameer Ajmani schreef op de 21e dag van de bloeimaand van het jaar 2012:
>
> > ping Peter : I'd like to submit your patches, but we need you to sign the
> > CLA first. Please see the instructions in my previous email.
>
> I did sign it, the day I got your previous mail. Did something
> go wrong? I didn't get an error message. Should I try signing
> again?
>
>
>
>
>
> --
> Peter
>

[Sameer Ajmani, 2012-05-29 16:40:03]

LGTM

[Sameer Ajmani, 2012-05-29 16:40:41]

*** Submitted as http://code.google.com/p/go/source/detail?r=798239220647 ***

Emacs go-mode: fix Emacs freeze-up when copy/pasting from string or comment.

Fixes issue 3509.
Fixes issue 2767.

R=golang-dev, sameer
CC=golang-dev
http://codereview.appspot.com/6139066

Committer: Sameer Ajmani <sameer@golang.org>