Alasql: indexedDB engine not throw onerror on IOS 9.3.5 mobile safari

[Eflet]

Hi,
Thanks for the great library.
I'm using alasql to store data into indexeddb and read data again when user refresh page. It works well on almost every browser except IOS 9.3.5 mobile safari. It will throw an 'onerror' exception and without any information.

My testing code is simple:

1. Create indexeddb database if not exists
2. Attach indexeddb database
3. Create table
4. Delete table manually (not using alasql, just use native code deleteObjectStore )
5. refresh page and do 1-3 again, crash at step 3

I read the source of 91indexeddb.js, and find the 'onversionchange' event seems not correct, here is what I find from stackoverflow:
https://stackoverflow.com/questions/43215199/indexeddb-onupgradeneeded-event-never-finishes

[Ronsor]

iOS 9.3.5 is outdated?