New page missing from site_pages array since 1.6.9?

I have noticed an issue with $PREFS->ini(‘site_pages’) on sites running 1.6.9 or later.

I know that there was a change to the pages logic in 1.6.9 as documented here: http://expressionengine.com/legacy_docs/installation/version_notes_1.6.9.html

But I have realised that when you submit a new weblog entry with a pages URI specified, that latest page is not included in $PREFS->ini(‘site_pages’)[1][‘uris’] (1.6.9 +) whereas it was included in $PREFS->ini(‘site_pages’)[‘uris’] (1.6.8). Once you update the new page, it is included in the array as expected.

To put some context on this, I discovered the issue when I realised that new page URLs added in 1.6.9+ were not working with LG htaccess generator, but once the page was edited it worked fine. I realise that this is a 3rd party extension, but in debugging the issue, I realised that the cause was just that the EE core variable $PREFS->ini(‘site_pages’)[1][‘uris’] was missing the new page URL post submission. In the same extension on 1.6.8, $PREFS->ini(‘site_pages’)[‘uris’] contains the new page URL and works fine.

While the site_pages array composition changed in 1.6.9, I can’t see why this should affect which pages the array should contain. Were there deeper logic changes made at the time? How can I get the site_pages array includes a new page that has just been added?

Thanks for your time