A message that failed for a passing reason (a dropped connection, a
server error, an expired token) used to count as done, so continuing
the import skipped it for good, and a slow upload followed by a cancel
imported the messages after it twice.
- The checkpoint keeps every message that is done, also past a gap,
and the next run of the same import tries only the rest again.
- Ten failures in a row, a full mailbox (overQuota) or a refusal
(forbidden) stop the import with a message instead of going through
the whole file.
- An upload without an answer pauses the import instead of failing the
message: 30 seconds, then until the upload window ends.
- Email/import, the export's Blob/get and folder listing pass the
client's own 429 pause by, and a 429 on them doesn't pause the rest
of the app.
- Signing out stops the job of that account only, writes no checkpoint
and imports nothing more afterwards; another account's sign-out
leaves the job alone.
- One tab imports a file at a time (Web Locks), and Import waits until
the dialog knows whether an earlier run can be continued.
The import dialog tests now wait for the Import button to be enabled
before clicking it, since it stays off during that lookup.
Linus Rath