It was recently brought to our attention that a change to the context menu handling code has broken some extensions that built on the context menu. Davide Ficano found one of his extensions was broken when we replaced a property on the gContextMenu object, a helper object used to manage the context menu. The change was made in bug 449522 to accommodate new video element support.
I saw Davide’s blog post, but it sat in my many open tabs. Thankfully, Mike Kaply got my attention this morning on IRC. We filed bug 497098 and got a patch up and reviewed. Hopefully, this minimal fix will make it into the next Firefox 3.5 release candidate. SeaMonkey has a similar bug open.
This change has been in Firefox 3.5 (nee 3.1) since beta 2. We got a fix ready to go in around two days after the initial blog post mention. What could we have done to have seen this breakage months ago, when it initially landed?
UPDATE: The patch landed on trunk and the 3.5 branch. Thanks to everyone involved.