当地时间今天早上，Mozilla的Nightly网站开始用"Minefield"标识测试Firefox 4.2 Alpha版本，而根据开发计划，Firefox 5也将在今年6月份启动。Firefox 4.2 Alpha基于现有的4.0版本开发，目前暂时向上不支持扩展，代码也处于不稳定状态，值得注意的是我们还看到了官方版的64位产品。
访问:Firefox Nightly Builds
Fixed:
#644139 [Toolkit:Build Config]-mozapps/preferences no longer included in omni.jar (Change Master Password dialog doesn't work) [All]
#644164 [Core:Build Config]-make configure depend on the various version files [Win]
#638292 [Toolkit:Add-ons Manager]-InstallTrigger is not defined when a new page is opened by clicking a link with target="_blank" or using window.open [All]
#639090 [Toolkit:Startup and Profile System]-Safe Mode dialog doesn't allow the user to restart in normal mode [All]
Partial Landings/WIPs/Incoming:
#636190 [mozilla.org:Release Engineering]-Change firefox version on mozilla-central to 4.2a1pre [All]
#259861 [Core:XBL]-Should log errors on bindings with no id attribute [Lin]
#457102 [Core:DOM]-kill nsIXPointer [Mac]
#585786 [Core:XPConnect]-Get rid of slimwrapper checks in quickstubs when we can [Mac]
#595785 [Toolkit:Download Manager]-Getting a download's nsIChannel appears unreliable [All]
#601332 [Core:Layout]-Sunspider 0.9.1 never paints its subframe [Win]
#614145 [Core:XPConnect]-Fast-path null return values in quickstubs [Mac]
[BACKOUT]#617339 [Core:HTML: Parser]-window.arguments is undefined when opening an HTML file with a long-ish comment at the start. [Mac]
#632904 [Core:Editor]-Editor/IME/spellcheck use content states when they mean IsEditable() [All]
#636336 [Core:DOM: Core & HTML]-img/video/audio/source.setAttribute()/getAttribute() on src trims whitespace [All]
#637644 [Core:DOM: Core & HTML]-adding elements through javascript to Popup windows does not work. [All]
#643429 [Core:Geolocation]-Remove IsBetterLocation functionality [Mac]
#640201 [Core:Geolocation]-mGeolocation should NOT be set before Init() is called [All]
Regressions/Annoying/Common bugs:
None.
