Yann Dirson [off-list ref] writes:
The current behaviour strips out lines starting with a # even when fed
through stdin or -m. This is particularly bad when importing history from
another SCM (tailor 0.9.23 uses git-commit). In the best cases all lines
are stripped and the commit fails with a confusing "empty log message"
error, but in many cases the commit is done, with loss of information.
I agree with this in principle but we would need to make sure
that our own scripts do not expect that the message is cleaned
up when feeding a commit log message via stdin, -m or -F, and if
they do fix them before applying this patch.