There are some cases like remote usage where this might cause
problems, but those users can easily customize the variable. The
inconvenience seems to be outweighed by the security benefit for most
users.
Previously notmuch-wash made the width of the text (approximately) the
window-width minus the depth in thread. This is correct for the
default indentation of 1 per message depth, but is incorrect for any
other setting of notmuch-show-indent-messages-width.
As notmuch-show-indent-messages-width is customisable, and notmuch-tree
sets it to zero to avoid indenting messages in the message pane, this
bug can show up in real use.
Two of the tests had to be updated: when
notmuch-show-indent-messages-width is 0, then the new (correct) word
wrapping happens later, when notmuch-show-indent-messages-width is 4,
then the new word wrapping happens sooner.
When no decryption or signature examination is
happening (i.e. `notmuch-crypto-process-mime' is `nil') insert buttons
that indicate this, rather than remaining silent.
Previous behaviour was to indent messages in a thread according
to depth by one space per level. This commit tests if setting
notmuch-indent-messages-width to `4' provides a message thread
with four spaces of indentation thread depth.