Files opened by "Copy to" on iOS are not re-openable

[amake]

On iOS, files can be opened from other apps in two ways:

• "Open in MyApp"
  • Received in application(_:open:options:) as an "open in place" security-scoped resource
  • options map contains UIApplicationOpenURLOptionsOpenInPlaceKey: true
• "Copy to MyApp"
  • Received in application(_:open:options:) as a regular (non-security-scoped) file URI
  • File is already copied to app container, so can always be persistently accessed
  • options map contains UIApplicationOpenURLOptionsOpenInPlaceKey: false in my observation (could hypothetically have nil or the key might be absent)

Previously, I thought that with correct setup (proper keys in Info.plist), all apps would be able to "Open In", but it turns out that some, in particular Google Drive, can never "Open In" but only offer "Copy To", regardless of the target application and its capabilities.

file_picker_writable currently handles receiving "Copy To" files OK: it ignores the failure to obtain a security scope in _prepareUrlForReading: https://github.com/hpoul/file_picker_writable/blob/72470d06f366039c568cd216fb5ccc6608cb9326/ios/Classes/SwiftFilePickerWritablePlugin.swift#L188-L198

But when trying to reopen a bookmark obtained from such a file, it fails due to strict checking in readFile: https://github.com/hpoul/file_picker_writable/blob/72470d06f366039c568cd216fb5ccc6608cb9326/ios/Classes/SwiftFilePickerWritablePlugin.swift#L104-L106

[amake]

Now this PR fixes #4 as well.

[amake]

Thanks for merging. But somehow I don't see it in the master branch.

[hpoul]

oops sorry.. no idea how that happened.. i think i've did one force push too many.. thanks for catching that 🤦️