These were originally written while the plugin was in draft. These can
be now removed as the RFC has been finalized and the commands were
dropped.

lib-sieve: plugins: imap4flags: test-hasflag - Fix segfault occurring for command without arguments.

This is a corner case that doesn't happen in practice, but it can be created in
the test suite.

This reverts commit ffbcd3bf.

lib-sieve: enotify extension: mailto: Enforce subject header limit in Unicode codepoints rather than bytes.

It was "i;octet" previously, which is not standard.

Providing an out-of-range index caused an assert panic.

Panic was:

Panic: file mail-index-transaction-update.c: line 19 (mail_index_transaction_lookup): assertion failed: (seq >= t->first_new_seq && seq <= t->last_new_seq)

Fixes assert failure occurring either at compiletime or at runtime (depending on
whether the value originates from variable).

Fixes assert failure occurring at runtime (when value originates from variable).

Compile error is avoided by putting the mailbox name in a variable, which is
(currently) only evaluated at runtime.

Before, it would only terminate the test when it failed explicitly using the
test_fail command.

This holds a reference to the initial result, causing it to linger after
test_result_reset, thereby also holding a reference to the message context,
preventing it from being cleared. This in turn, can keep references to modified
message versions that cause the main message object to remain referenced. This
causes a panic in specific cases upon test_result_reset:

Panic: Input stream data unexpectedly has references

Caused a panic when input was not valid. This is only relevant to the test suite
and doesn't occur anywhere else (apart from the previous similar commit for
lib-sieve-tool).

Panic was:

Panic in file smtp-address.c: line 684 (smtp_address_write): assertion failed: (smtp_char_is_qpair(*p))`

The segfault happens when this match type is the last argument of the test
command. This situation is not possible in a valid script; positional arguments
are normally present after that, which would prevent the segfault. A variant of
this bug occurs when the match type also has no argument of its own. In either
case the segfault is caused by referring to absent tag arguments, which causes
a NULL dereference.

The use of a variable substitution erroneously produced a runtime syntax error.

Also check the X-Sieve-Redirected-From header for our own e-mail addresses. This
header is added by the redirect action itself and in a mail loop it would see
that same header with that same content. This is less reliable than the other
mail loop detection (sender may set such a header), so, unlike the existing loop
detection based on the duplicate db, the implicit keep is not canceled when the
new loop detection is triggered.

test suite: enotify extension: Add tests for interaction between ":encodeurl" and variable size limits.