Lost PDF filenames (multiple share) about cool-maze

[Deleplace]

Today I tried sharing 2 PDF from the Files app on a Samsung Galaxy S22. The filenames were properly transmitted, in the target web UI and in the resulting ZIP as well.

[Deleplace]

For debugging this issue: note that the backend only sees an opaque encrypted value for the filenames. It cannot see the clear text filenames.

[Deleplace]

Today I tried sharing 2 PDF from the Files app on a Google Pixel 7. The filenames were lost! The contents listed in the ZIP showed up as:

• undefined
• 1_undefined

[Deleplace]

When sharing these files individually, from the same Pixel 7, the filenames are properly preserved. They were lost only when shared together in a single action.

[MaBeuLux88]

This sounds very similar to my bug. I got the same filenames. No file corruption though. Just file name alterations.

[Deleplace]

While I don't have access to the filenames, I can still extract stats about shares that don't seem to be providing a proper filename.

Results:

• iOS app mostly unaffected
• Android app affected: ~7% of files transmitted end up without a proper filename
  • it is possible that some source apps don't provide a filename when sharing a resource
  • but more probably, the Cool Maze Android app failed to properly extract the filename from the Intent
• no obvious correlation with the OS version (Android 6, 7, 8, 9, 10, 11, 12, 13, 14)
• no obvious correlation with the smartphone device model
• no obvious correlation with the mime type of the file
• no obvious correlation with the number of resources shared in one action. Filenames can be lost either in a single share action, or in a multiple share action.