Apple today released Mac OS X 10.5.5, rolling in a large number of bug fixes. As far as we can tell, there are no new features, but thanks to Apple's moderately detailed release notes (thanks, Apple!), users can get a sense of whether or not 10.5.5 is likely to resolve particular problems.
For instance, Apple claims the update addresses MacBook Air stability issues with video playback, processor core idling (the heat-related issue wherein a MacBook Air would shut down one of its two processor cores), and remote disc sharing. It's unclear how this is similar to or different from the fixes in MacBook Air Update, which also claims to resolve a processor core idling problem.
Other general bug fixes solve a problem that could cause a Mac to turn on unexpectedly at the same time every day, a stability issue with using the color palette in TextEdit, problems syncing contacts properly to Palm OS-based devices, improved reliability when rebuilding a software mirror RAID volume in Disk Utility, and Kerberos authentication issues for Mac OS X 10.5 clients connecting to certain Samba servers (including Mac OS X Server 10.4's Samba server - oops!).
General improvements include better Spotlight indexing performance, an improved Speech Dictionary, and extensive graphics enhancements.
Time Machine -- It's hard to avoid comparisons between Apple's Time Machine and Dr. Who's sometimes-recalcitrant TARDIS, given how Time Machine works well for most people most of the time, but occasionally refuses to back up, gets stuck in the middle of backups, or confuses users with odd error messages. And like the good doctor, Apple is continually working on Time Machine, now improving reliability with Time Capsule, addressing performance issues with initial and in-progress backups, and addressing a spurious message that claimed a backup volume lacked sufficient space.
Most interesting is the note that "Time Machine can now back up iPhone backups that are on your Mac, as well as other items in (~/Library/Application Support)." Does that mean that Time Machine hasn't been backing up iPhone backups or other items in the Application Support folder? That's not reassuring.
Improved Mail Handling -- A number of the fixes in Mac OS X 10.5.5 revolve around Mail, specifically in relation to robustness. Apple addressed stability issues that could result in crashes or other problems when dragging items to Mail's icon in the Dock, saving drafts that have attachments (a particularly annoying one, since it's good form to attach documents early in the writing of a message to avoid forgetting the attachment), and in sending messages.
The update also improves Mail's performance when displaying IMAP messages and fixes problems related to SMTP settings for popular mail hosts CompuServe, Yahoo, Time Warner Road Runner, and Hanmail. Lastly, the new version of Mail resolves the temporary disappearance of RSS feeds from the sidebar and makes sure dates appear in collapsed threads when using the Organized by Thread view.
MobileMe and iCal -- Apple's release notes don't go into much detail on this front, but the words "Improves overall sync reliability" are sure to sound welcome to the small minority of MobileMe subscribers who continue to see syncing problems with the online service.
The updates to iCal include fixes for handling repeating events and working with meeting attendees. Also listed is resolution of an unspecified "issue with syncing published calendars."
Back to My Mac apparently has also been gifted with "improve[d] reliability," but in what way, Apple isn't saying.
Patching DNS -- Security Update 2008-006, installed as part of 10.5.5 and available separately for Mac OS X 10.4.11, includes dozens of obscure items that only system administrators can love, as well as several important fixes related to DNS.
As we have written extensively, a flaw in most systems that handle DNS lookups - the conversion of a human-readable domain name into a machine-usable number - could allow criminals and ne'er-do-wells to redirect Web browsing and other traffic to servers operated for malicious purposes. (A legitimate request for www.amazon.com could be returned with a forged IP address for a site run by bad guys.) See our series "DNS Flaws Could Have Led to Disaster," for full details.
In this security update, Apple cleans up three additional items related to the DNS flaw. BIND, the daemon software that handles DNS lookups, was updated to version 9.3.5-P2 for Tiger systems and 9.4.2-P2 for Leopard systems. The first patch (P1) of both releases was known to have performance issues under heavy load, a situation in which ostensibly only a few Apple server systems might find themselves.
More significantly, Apple updated libresolv, an underlying system library that provides DNS resolution - the aforementioned lookup of name to number - which is used by applications. This doesn't affect most Mac OS X operations, but programs that have specialized needs for DNS lookups required this update. It's unclear what lower-level and graphical software would be affected by this update.
Finally, mDNSResponder was also patched in this release, following a similar fix in the iPhone 2.1 and iPod touch 2.1 software. mDNS is the protocol which Bonjour uses to pass information over a local network, and, as such, is subject to the same kind of weaknesses that plagued regular DNS.
Clarity in File Sharing -- Another item of interest is a change to how the Sharing preference pane will now display what's accessible in the File Sharing service. Previously, the File Sharing service listed only folders and volumes that you had manually set to be shared, along with the Public folder in your Home folder. (This drove Glenn crazy while working on revisions to "Take Control of Sharing Files in Leopard," because the list's contents were inconsistent with what was actually available.)
The File Sharing service now shows in the Shared Folders list all folders that are shared, including Public folders in other local users' home directories. Apple added a note - a little subtle if you ask us - that explains that all local volumes (the boot drive and all mounted drives) can also be shared by anyone with administrative access.
Tiger Flashes Its PPP -- A particularly silly error in Tiger was fixed in this update: passwords used for PPP connections, typically used for dial-up modem connections, were apparently stored "unencrypted in a world readable file." Given the credit lists three seemingly unrelated people, this flaw may have been known for some time.
Minor Mac OS X Server Updates -- Apple also shipped a separate Mac OS X Server 10.5.5 update that incorporates what appear to be a few dozen fixes to relatively minor bugs in file services, collaboration services, directory services, the Active Directory plug-in, and various utilities. In addition, the WebObjects 5.4.3 Update is included to address several bugs. It's also available as a standalone 158.5 MB download.
Getting the Updates -- Mac OS X 10.5.5 is available via Software Update, or as the following standalone downloads: a delta updater (316 MB) for updating from the client version of Mac OS X 10.5.4, and a combo installer (601 MB) for updating from any client version of Mac OS X 10.5.0 through 10.5.4. Mac OS X Server 10.5.5 also comes in a version for updating from version 10.5.4 (341 MB) and in a combo updater (729 MB).
Security Update 2008-006 is available in four versions of Tiger: for the PowerPC version of Mac OS X 10.4.11 (67.7 MB), for the Intel version of Mac OS X 10.4.11 (157 MB), for the PowerPC version of Mac OS X Server 10.4.11 (118 MB), and as a universal version for Mac OS X Server 10.4.11 (118 MB). Honestly, it's easiest to let Software Update do its thing.