Issue w/ the cache subsystem

[Emmanuel Blot]

When a new component is added, through the webadmin interface, it may or may not appear in the Ticket page.

I've bumped into two different cases:

1. The new component is added after a "New ticket" page is filled in, and before the new ticket is submitted. A "Preview" action used to reload the new ticket page and update the selection list on-the-fly, allowing to set the newly created component before creating the actual ticket.
   • this feature worked, but when the ticket got submitted, the server rejected the new component as "Invalid": it looks like several instances of the Trac server do not get synchronized as they should fo
2. Far worse, regular case: the new component is added after the ticket is created. When the ticket page is reloaded, to update the component, the newly created component does not appear at all in the selection list. Trac is desynchronized:
   • the new component does appear in the webadmin view
   • the new component keeps missing in the ticket view

Trac:	0.12dev-r8139
Python:	2.5.4 (r254:67916, Feb 17 2009, 20:16:45) [GCC 4.3.3]
setuptools:	0.6c9
SQLite:	3.6.13
pysqlite:	2.5.0
Genshi:	0.6dev-r1052
Babel:	-
Pygments:	1.0
Subversion:	1.5.6 (r36142)
jQuery:	1.3.2

[Emmanuel Blot]

Note: as expected, reloading Apache solves the cache issue (/etc/init.d/apache2 reload)

[Remy Blank]

Replying to eblot:

Trac is desynchronized:

• the new component does appear in the webadmin view
• the new component keeps missing in the ticket view

That's bad. Is this sporadic, or does it happen every time you add a component? I'm pretty sure I had tested this case, but I must have missed something.

Could you please give me the output of:

SELECT * FROM cache;

[Emmanuel Blot]

Replying to rblank:

That's bad. Is this sporadic, or does it happen every time you add a component?

Up to now, I've only added two components since the upgrade, and I got the two errors I've described in the ticket description.

Could you please give me the output of:

sqlite> select * from cache;
trac.wiki.api.WikiSystem.pages|0
trac.ticket.api.TicketSystem.fields|0

[Remy Blank]

I can only reproduce this the first time around, that is, when the cache table does not yet contain a given cache key. Subsequent additions of components are picked up correctly by other processes.

Was this the first time you added a component (or any new ticket field value) since upgrading your installation to a version of trunk containing the new caching code?

(Mid-air collision)

Ok, so it looks like you had exactly that scenario. Adding new components now should work. I'll fix the initial case, but I don't know yet what's happening.

[Remy Blank]

Ok, fixed in [8158]. The issue was due to a bad ternary operator ersatz. This kind of bug will stop being introduced when we drop Python 2.4 support and we can finally use the real ternary operator ... if ... else ....

Thanks for the bug report!