Nanako Shiraishi [off-list ref] writes:
Teach a new option, --autosquash, to the interactive rebase.
When the commit log message begins with "!fixup ...", and there
is a commit whose title begins with the same ..., automatically
modify the todo list of rebase -i so that the commit marked for
squashing come right after the commit to be modified, and change
the action of the moved commit from pick to squash.
Signed-off-by: Nanako Shiraishi <redacted>
Hmph, did you forget to retitle the message, or keep in-body "Subject:"?