Previous cleanups (mostly the removals of Python __future__ imports)
were done in a way that introduced leading newlines. Delete leading
newlines from all files, except static/assets/zulip-emoji/NOTICE,
which is a verbatim copy of the Apache 2.0 license.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
Using sys.exit in a management command makes it impossible
to unit test the code in question. The correct approach to do the same
thing in Django management commands is to raise CommandError.
Followup of b570c0dafa
This fixes an issue where passing a path like `~/exports/foo` would
result in a `~` directory being created and the export/import not
working correctly.
Significantly tweaked by tabbott because:
* Argparse was already handling the early checks
* Splitting the bottom loop into two loops means we validate all the
input before trying to run actual import code on anything.
* The argparse documentation was confusing about whether the paths
should be files or directories.
When you're importing with --destroy-rebuild-database, we need to
check subdomain availability after we've cleared out the database;
otherwise, trying to reuse the same subdomain doesn't work.
The previous export tool would only work properly for small realms,
and was missing a number of important features:
* Export of avatars and uploads from S3
* Export of presence data, activity data, etc.
* Faithful export/import of timestamps
* Parallel export of messages
* Not OOM killing for large realms
The new tool runs as a pair of documented management commands, and
solves all of those problems.
Also we add a new management command for exporting the data of an
individual user.