Archive for October 1, 2018

Monday, October 1, 2018

iOS 12 and Core Data External Binary Data Storage


On iOS 12, binary data stored in Core Data with the External Storage option gets corrupted/goes missing on every second save of the context.

Others seem to be encountering the same issue. External storage is so convenient, but it seems to be a continual source of problems and bugs.

Previously: Core Data, External Binary Data Storage, and Migration.

Update (2018-10-02): See also: Hacker News.

Update (2018-10-04): See also: some Twitter discussion.


Language bindings are a minor issue - here’s my POV: I have to ship a reliable product. With data loss like external stores disappearing I’m SOL, and it’s in a codebase that I cannot fix or guarantee a fix to. Sure, my SQLite model will be slower, but correct


I can live with slower, even an order of magnitude so, over data loss. The business costs are huge for the latter. Even the emotional costs, what if I lose someone’s pictures of a deceased loved one? There’s a human on the receiving end of my program most of the time...

Drew McCormack:

Ouch! Just got bitten by a serious Core Data bug in macOS 10.14 and iOS 12 with external binary storage. Firefighting all day to save my user’s data.

It’s in an old app (Studies). Created the model about 10 years ago. I’ve learnt my lesson with external binaries.

Ensembles is not affected.

Ilja A. Iwas:

There are days when I wonder if it was worth coming up with our homegrown CoreData replacement. And then there are days like today.

The Omni Group wrote OmniDataObjects because Core Data was originally not available on iOS, and OmniFocus continues to use it.

Ilja A. Iwas:

If Apple doesn’t allocate enough resources for screening incoming bug reports during their beta phase, sticking to a yearly macOS release schedule is not responsible to users and developers. Small indy devs probably don’t recover from such hits.

It looks like NSBatchDeleteRequest also doesn’t work with external binary data.

Update (2018-10-05): Colin Cornaby:

So we’ve done our best to try and repro the iOS 12/Core Data External Binary Storage bug in our apps… and we can’t.

I’m not saying the bug doesn’t exist. I know it does. I just don’t know why we can’t repro it in our apps, and it’s driving me crazy.

Forcing Suspect to Unlock iPhone With Face ID

Tim Hardwick:

A Forbes report has highlighted the first known case of law enforcement forcing a suspect to unlock an iPhone using Face ID.


Several previous cases have occurred where law enforcement has gained access to digital data by forcing people to unlock mobile devices using their fingers. One case even reportedly involved trying to use the finger of a dead person to unlock a phone, which ultimately didn’t work.

Previously: Police Can Require Cellphone Fingerprint.

Update (2018-10-15): Tim Hardwick:

Police in the United States are being advised not to look at iPhone screens secured with Face ID, because doing so could disable facial authentication and leave investigators needing a potentially harder-to-obtain passcode to gain access.

Update (2019-01-15): Juli Clover:

Law enforcement officials can’t force smartphone users to unlock their devices using fingerprints or other biometric features such as facial recognition, according to a Northern California court ruling from last week.

The Rise and Fall of The Learning Company

Abigail Cain:

Both Reader Rabbit and Cluefinders were the work of The Learning Company (TLC), a dominant player in the realm of educational software during its peak in the late 1980s and ’90s. At a certain point, TLC owned pretty much every computer game that mattered to millennials: The Logical Journey of the Zoombinis, Where in the World Is Carmen Sandiego?, even Oregon Trail. But by 2000, the company was in financial shambles — and, in what was labeled one of the worst business deals of all time, almost took a Fortune 500 company down with it.


SoftKey renamed itself The Learning Company to take advantage of its strong reputation, continuing to gobble up industry powerhouses including MECC, in 1995, and Brøderbund, in 1998. All told, SoftKey bought more than 20 entities, becoming the world’s second largest consumer software company after Microsoft in the process.


According to Osterwiel, the industry never fully recovered. The problems that plagued it during its previous downswing persist today, albeit with more advanced technology. Apps are the new medium for educational games — but they sell for $1 apiece, an amount that would have been “the price of postage” to mail a game on CD-ROM, Buckleitner noted wryly. Quality research and development is practically impossible with that sort of profit margin.