Re: -[NSManagedObjectContext save:] fails but gives no NSError

FROM : Jerry Krinock
DATE : Sat Nov 24 06:47:41 2007

On 2007 Nov, 23, at 14:46, mmalc crawford wrote:

> Under what circumstances is it not setting an error?


Unfortunately, I can't say for sure, because when it wouldn't tell me 
what the error was, I took a broad look at what the hell I was doing 
and realized that my code and data model were maintaining an 
unnecessary entity.  It looked like, prior to the -save:, I could have 
been either (a) inserting or deleting the same objects twice, or (b) 
inserting objects with relationships to objects that had been 
deleted.  (Multiple objects had relationships to the same other 
objects, with Delete Rule = 'Cascade'.  Oops.)  But once I realized 
that these other objects were not necessary, I got rid of their entity 
and all that code, and things have been saving happily ever since.

What I am sure about is that, as per the code in my original post, 
although I was giving -save: an NSError**, it was returning NO, my 
store file on the disk was not touched, and the NSError* was nil.

If it ever happens again, I'll test more closely and let you know.