Although a lot of things have changed in Firefox 10 that, in theory, can cause add-on compatibility breakage, most of them are relatively obscure, so they're not very likely to affect you. This article will help guide you as you update your add-on.
The first and most important thing to note is that starting in Firefox 10, add-ons are assumed to be compatible by default. Unless you use the
<em:strictCompatibility> flag in your manifest, Firefox will no longer mark your add-on as incompatible after an upgrade to Firefox 10 or later. You can use that flag to ensure that an add-on that is likely to break will not try to run in updated copies of Firefox. It's worth noting that add-ons that have binary components will always be strictly checked for compatibility, since binary components always need to be recompiled for each major Firefox release.
Some obsolete APIs have been removed from the DOM:
===operator to compare nodes instead of this obsolete method. This method was made obsolete by the DOM4 specification.
- These APIs were rendered obsolete by the DOM4 specification.
- All of these APIs were rendered obsolete by the DOM4 specification. They were most frequently being used to detect whether the document being displayed was HTML or XML. See the article for
Document.xmlVersionfor a recommended way to test for this going forward.
The most significant change is that everywhere that previously used the
PRBool data type now uses the standard C++
bool type instead.
The following interfaces have been removed:
nsNavHistoryno longer implements the
nsICharsetResolverinterface. Note that
nsICharsetResolveris no longer used and is being removed in Gecko 11.0 (Firefox 11.0 / Thunderbird 11.0 / SeaMonkey 2.8).
nsIEditorSpellCheckinterfaces have been updated to let restartless add-ons add dictionaries to the spell checker. See Using an external spell checker for details (note this article has not yet been updated, but will be soon).
nsIBrowserHistory.lastPageVisitedattribute has been removed, as it hasn't been supported for some time.
- Several IndexedDB internal interfaces have changed to support revised APIs. This shouldn't affect you but is worth noting on the off chance you were doing something unusual.
- All binary components on Windows should be built with ASLR (address space layout randomization) support enabled. While this is not yet required, it may be in the future, and not enabling it results in a performance penalty.
- A bug in regular expression handling that was introduced in Firefox 7 has been fixed. This can change the result of some regular expressions, so be aware of it.
- You can now dynamically load and unload chrome.manifest files in bootstrapped add-ons.
mouseleaveevents are now supported.