Drupal: Broken RSS feeds

In Drupal 5, the path www.example.com/rss.xml will produce an RSS feed of the most recent nodes (the number of items can be customised in the RSS publishing options; the default is ten), and other core modules provide feeds, such as taxonomy, via www.example.com/taxonomy/term/1/0/feed. I had a problem recently where this functionality appeared to stop working. RSS feeds would not be displayed, and a ‘page not found᾿ (404) error would appear instead.

At first, I suspected a module might have been to blame. After all, the RSS functionality worked on a simple site, but not the one I was working on, which had been customised with lots of modules. I disabled all the modules that could have possibly affected the RSS feeds, but this did not help at all.

It turns out that URL aliasing was to blame. I had inserted some rows manually into the {url_alias} table, but I had put the values into the wrong columns. The two columns in question were src and dst. The dst column is the column containing the URL the user goes to, and the src column is the one that it is aliases to, ie the ‘real’ URL. I had put the values into these columns the wrong way around, so when requesting the RSS feed's URL, Drupal was redirecting to a gibberish URL that did not exist!