Two queries run when clicking on a changeset

[theuni]

I noticed cpu usage on my mysql database (which is already very high) remains high longer than it should. It appears as though two revisions are being queried for each revision visited.

See log:

2010-02-02 22:52:41,615 Trac[main] DEBUG: Dispatching <Request "GET u'/changeset/24210'">
2010-02-02 22:52:41,622 Trac[session] DEBUG: Retrieving session for ID u'theuni'
2010-02-02 22:52:41,626 Trac[chrome] DEBUG: Prepare chrome data for request
2010-02-02 22:52:42,752 Trac[main] DEBUG: Dispatching <Request "GET u'/changeset/24211'">
2010-02-02 22:52:42,757 Trac[session] DEBUG: Retrieving session for ID u'theuni'
2010-02-02 22:52:42,762 Trac[chrome] DEBUG: Prepare chrome data for request

To reproduce: click a revision X, and see that X and X+1 are requested.

Using: trac 0.11.6, mysql, apache2+wsgi

[Remy Blank]

The fact that you get two GET entries in the log means that your browser actually performs these two requests, so there's nothing Trac can do about that. This is most probably due to the browser prefetching pages directly linked by a page. What browser are you using? Can you reproduce the issue with other browsers?

[anonymous]

Only reproduced in firefox v3.6, after that I managed to break my install. Will try again tomorrow after I fix.

Also worth noting: only seemed to happen when logged in.

[Christian Boos]

Yeah, this is Firefox specific, and you can disable that feature if this annoys you.

E.g. tips from ​http://www.technipages.com/disable-the-firefox-prefetch-setting.html:

1. Type about:config in the address bar and press ENTER.
2. Locate and double-click the entry for network.prefetch-next
3. Set it to false to disable this feature. Double-clicking on the setting will change it.