[Bug] App crashes on iOS 10 when the internal implementation attempts to set `AllowsMultipleSelection`

[1Cor125]

Description

App crashes when calling PickFileAsync on iOS 10.

Steps to Reproduce

1. Call PickFileAsync(options) on iOS 10.
2. App crashes with UIDocumentPickerViewController.set_AllowsMultipleSelection (System.Boolean value) SIGABRT: This API is not supported on this version of iOS

Expected Behavior

We should be wrapping this line of code in a version check but we are only checking the version at the beginning of the method when deciding whether to respect the allowMultiple parameter.

Actual Behavior

We should be doing this:

if (Platform.HasOSVersion(11, 0))
    documentPicker.AllowsMultipleSelection = allowMultiple;

Basic Information

• Version with issue: 1.6.0-pre2
• Platform Target Frameworks:
  • iOS: 10.3.3 (any pre 11 version)

[mattleibow]

I think this was fixed in a different way:

Essentials/Xamarin.Essentials/FilePicker/FilePicker.ios.cs

Lines 16 to 17 in 044c92d

	if (allowMultiple && !Platform.HasOSVersion(11, 0))
	throw new FeatureNotSupportedException("Multiple file picking is only available on iOS 11 or later.");

But, I think to be consistent, it should not throw and just allow single files to be picked.

[1Cor125]

Thanks for the response @mattleibow. Yeah the trouble is even if allowMultiple is false we still attempt to set the property so even when the user correctly uses the API (only using PickFileAsync on iOS 10) it blows up.

[mattleibow]

Ah yeah. I didn't even notice that. Not very smart of us.