I had a customer feedback about a "zero length data" error which was captured using an exception handler and displayed using NSAlert.
My app employs [NSURLSession dataTaskWithURL:] to download XML and image data.
But I got no idea what it is about. I assume it's related to NSData, but this error never happened before (for years).
Does anyone have any idea about the source of this error?
Anyway, I found out the cause.
The error is thrown when initializing XMLDocument with an empty string:
let xd = try XMLDocument(xmlString: "")
captured using an exception handler and displayed using NSAlert.
Don't do that; let the app crash, and then look at the crash logs that Apple will send you. These will include a stack trace so you'll have some chance of identifying the cause.
If you really want to trap fatal exceptions yourself, include more diagnostics.
Anyway, I found out the cause.
The error is thrown when initializing XMLDocument with an empty string:
let xd = try XMLDocument(xmlString: "")