cool#9072 browser: better error handling when navigator.clipboard.write is advertised but fails

[vmiklos]

In case an integration doesn't allow clipboard interaction via
https://sdk.collaboraonline.com/docs/advanced_integration.html#allow-the-clipboard-permission-query,
we end up in a situation where navigator.clipboard.write is not
undefined, but is broken.

By the time navigator.clipboard.write() fails, it's too late to fall
back to the old copy code, as the security context is already gone.

Fix the problem by improving the failure handling: show the popup to try
again copying, remember that navigator.clipboard.write() failed and
prefetch the text selection, so next time a copy is tried (via the
keyboard), the selection doesn't need re-creating. (Normally the
selection change would trigger the prefetch, so select->copy->copy-again
would still fail.)

Note that paste doesn't have a similar problem, since there we always
try the old paste code first, and only use the new paste code if the old
one fails.

Signed-off-by: Miklos Vajna [email protected]
Change-Id: I12ea4810395970421000d213744d1838213c7a07

[vmiklos]

Rebase to be on top of 873485f

[vmiklos]

@caolanm could you please review this? Thanks.

#9072 has some details on this, I went the more conservative route and even persist the disable flag in local storage (vs only setting the JS global to false, and try again on next doc edit). This should help with owncloud and other integrations which are left untouched at the moment and would see this as a 23.05 -> 24.04 regression. Nextcloud is not affected, I tested the change with a local revert.