Juraj Variny <[EMAIL PROTECTED]> writes:
> I ran into especially nasty bug in wwwoffle CGI interface. The output of any
> CGI script was completely empty except HTTP headers. In older versions (AFAIK
> 2.7e-2.8) of wwwoffle the bug was triggered sometimes by several
> online/offline/fetch cycles. With debugging output turned on, it happened
> never. With 2.8b it happened always after fresh start (except with debugging
> turned on, of course :-). This enabled me to nail it down. Here is simple
> bugfix patch against cgi.c in 2.8b.
I can't replicate the problem here. The code worked in previous
versions of WWWOFFLE and still works in the current version as far as
I can see.
> Hmmm, maybe splint could be made to check for trashing live file descriptor
> with dup2().
At first I couldn't see the problem, but I think that I have now.
When cgi_out[0] is closed it might be file descriptor 1 that
cgi_out[1] was replicated onto by calling dup2().
This would explain why I don't see the problem, I use the '-d' option
to wwwoffled which doesn't close file descriptors 0 and 1 and uses 2
for logging (I have changed it to close 0 and 1 in this case as well).
> --- cgi.c 2004-02-15 19:52:37.115156808 +0100
> +++ ../../wwwoffle-2.8.modified/src/cgi.c 2004-02-15 19:57:08.989825576 +0100
[snip patch]
I think that you need to close cgi_out[0] before the if() statement
rather than inside it since it should be closed in both cases.
It is probably also a good idea to make sure that there are file
descriptors 0, 1 and 2 when the CGI is run. There will be a 1 in all
cases and a 0 if using a POST request, but not a 2 unless using the -d
option.
--
Andrew.
----------------------------------------------------------------------
Andrew M. Bishop [EMAIL PROTECTED]
http://www.gedanken.demon.co.uk/
WWWOFFLE users page:
http://www.gedanken.demon.co.uk/wwwoffle/version-2.8/user.html
