Before the change, messages generated by generate_message() used "Test
message #N" for default subject where N is the generated messages
counter. Since message subject is commonly present in expected
results, there is a chance of breaking other tests when a new
generate_message() call is added. The patch changes default subject
value for generated messages to subtest name if it is available. If
subtest name is not available (i.e. message is generated during test
initialization), the old default value is used (in this case it is
fine to have the counter in the subject).
Another benefit of this change is a sane default value for subject in
generated messages, which would allow to simplify code like:
test_begin_subtest "test for a cool feature"
add_message [subject]="message for test for a cool feature"
The sleep was to force the directory's mtime to advance between the
previous notmuch new and the subsequent rm;notmuch new.
The current convention is to use the existing increment_mtime function
for this purpose, (which avoids the test suite being slowed down by
calls to sleep).
Thanks to Austin Clements for noticing this undesired sleep.
Test for bug. Current stemming support for notmuch adds extra terms
to the DB which aren't removed when the file renames are detected.
When folder tags are added to a message, Xapian terms for both XFOLDER
and ZXFOLDER are generated. When one of the filenames are
renamed/removed, only the XFOLDER tags are removed, leaving it possible
for a match on a folder: tag that was previously but is no longer a
match in the maildir.
