[Zope] Traps for the unwary...

[Graham King]

Just thought I'd mention in passing... no need for responses or navel
gazing. :)

We have two identical Zope envts on different OS platforms. (python 2.1.2,
gcc 2.95.3, Zope 2.5.0 on openBSD 3.0 and Solaris 8) 

We migrated a Zope DTML application from Solaris systems (where it worked
fine on 3 different Zope instances) to two openBSD systems.
An obscure bit of "superfluous" DTML code caused lib/python/DTML.py to
crash.

Of course, when using ProxyPass method, it caused Zope itself to crash, but
if we used FastCGI or port 8080, then it just failed...

The offending code (marked *)


        <dtml-if sequence-end>
*         <dtml-call "REQUEST.set('span', (5 -
(_.int(_.getitem('sequence-number')) % 4)) )">
*         <dtml-if "_.getitem('span') > 4"><dtml-call "REQUEST.set('span',
1)"></dtml-if>
        <dtml-else>
         <dtml-call "REQUEST.set('span', 1)">
        </dtml-if>


then fixed with:

	<dtml-call "REQUEST.set('span', 1 )">
	<dtml-if "_.getitem('span') > 4"><dtml-call "REQUEST.set('span',
1)"></dtml-if>


In hindsight, the programmer qualifies this with:

"ok.. but be prepared for some abuse about the shitty code.. I don't
remember what I was thinking at the time and I could not understand what I
was doing when I read it back.. that is generally a sign of bad code :)"


We're all still learning.... :) I was just surprised (read "horrified",
since it was production) that some DTML appln code would crash Zope itself.

I put it down to the vagaries of C compiles on different platforms.


cheers all
hope you have a code-free Easter holiday...

Graham