Re: Re: [PATCH] Use save-excursion in org-map-dblocks

[Carsten Dominik <carsten.dominik@gmail.com>]

On Mar 24, 2010, at 2:47 PM, Magnus Henoch wrote:

> Carsten Dominik <carsten.dominik@gmail.com> writes:
>
>> this looks like an OK patch and I don't have any problems applying  
>> it.
>> However, I do not quite understand the need for it.  Can you please
>> try to explain a bit better?  Do you have two processes running over
>> the same file at the same time, or why is there a conflict?
>
> My dblock-write function calls url-retrieve, to asynchronously  
> retrieve an
> HTML page.  The callback function I pass to url-retrieve will then  
> fill
> in the information I need into the dynamic block.
>
> So in the following case:
>
> * Find start of dblock 1, store as pos
> * Make HTTP request for dblock 1
> * Go back to pos
> * Find end of dblock 1
> * Find start of dblock 2, store as pos
> * Make HTTP request for dblock 2
> * Asynchronous event: HTTP response for dblock 1 arrives, insert  
> lots of
>  data in dblock 1
> * Go back to pos
> * Find end of dblock 2
>
> the last step will actually find the end of dblock 1, if the amount of
> data inserted in dblock 1 is great enough that pos suddenly points
> inside it.  (Then it will of course find dblock 2 again, request its  
> HTML
> page again, and thus insert the data twice.)
>
> An equivalent fix would be to make pos a marker instead.

Yes, that would be the same.

I have applied the patch, thanks.

Can I ask you to sign the FSF papers for future patches which might be  
more than a few lines?

Thanks.

- Carsten