When creating a patch set with cover letter using the
send-pull-request script, both the "In-Reply-To" and "References"
headers are appended twice in patch 2 and subsequent.
That's because git-format-patch already inserted them and then
git-send-email repeats that. Suppressing mail threading in
git-send-email with --no-thread avoids the problem and is the
right solution because it works regardless whether git-send-email is
called once or twicee.
Repeating these headers is a violation of RFC 2822 and can confuse
mail programs. For example, Patchwork does not detect a patch series
problem when there are these extra headers.
[YOCTO #10718]
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
