create-pull-request: add "-t in-reply-to" option

The create-patch-request script creates patches as replies to a cover
letter, in the form of an email thread. If further revisions are sent to
the mailing list without referencing to the first revision, these new
revisions are not identified at the mailing list as part of the original
thread, but as a new thread instead.

This change adds the "[-t in_reply_to]" option, where "in_reply_to" is
the original cover letter's Message-Id, so this reference is added
to the new cover letter to ensure the thread continuity.

[YOCTO #11294]

(From OE-Core rev: 8a3879a8ca71db7fb313417d86b3ac7904cb0f0e)

Signed-off-by: Jose Lamego <jose.a.lamego@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/create-pull-request

@@ -34,7 +34,7 @@ RFC=0
 usage() {
 CMD=$(basename $0)
 cat <<EOM
-Usage: $CMD [-h] [-o output_dir] [-m msg_body_file] [-s subject] [-r relative_to] [-i commit_id] [-d relative_dir] -u remote [-b branch]
+Usage: $CMD [-h] [-o output_dir] [-m msg_body_file] [-s subject] [-r relative_to] [-i commit_id] [-d relative_dir] -u remote [-b branch] [-t in_reply_to]
   -b branch           Branch name in the specified remote (default: current branch)
   -l local branch     Local branch name (default: HEAD)
   -c                  Create an RFC (Request for Comment) patch series
@@ -49,6 +49,7 @@ Usage: $CMD [-h] [-o output_dir] [-m msg_body_file] [-s subject] [-r relative_to
   -s subject          The subject to be inserted into the summary email
   -u remote           The git remote where the branch is located, or set CPR_CONTRIB_REMOTE in env
   -d relative_dir     Generate patches relative to directory
+  -t in_reply_to      Make mails appear as replies to the given Message-Id, to continue patch/series threads
 
  Examples:
    $CMD -u contrib -b nitin/basic
@@ -57,12 +58,13 @@ Usage: $CMD [-h] [-o output_dir] [-m msg_body_file] [-s subject] [-r relative_to
    $CMD -u contrib -r master -i misc -b nitin/misc -o pull-misc
    $CMD -u contrib -p "RFC PATCH" -b nitin/experimental
    $CMD -u contrib -i misc -b nitin/misc -d ./bitbake
+   $CMD -u contrib -p "OE-core][PATCH v2" -t "<cover.11146.git.john.doe@example.com>"
 EOM
 }
 
 REMOTE="$CPR_CONTRIB_REMOTE"
 # Parse and validate arguments
-while getopts "b:acd:hi:m:o:p:r:s:u:l:" OPT; do
+while getopts "b:acd:hi:m:o:p:r:s:u:l:t:" OPT; do
 	case $OPT in
 	b)
 		BRANCH="$OPTARG"
@@ -108,6 +110,8 @@ while getopts "b:acd:hi:m:o:p:r:s:u:l:" OPT; do
 	a)
 		CPR_CONTRIB_AUTO_PUSH="1"
 		;;
+        t)
+                IN_REPLY_TO="$OPTARG"
 	esac
 done
 
@@ -205,7 +209,11 @@ if [ -n "$RELDIR" ]; then
 fi
 
 # Generate the patches and cover letter
-git format-patch $extraopts -M40 --subject-prefix="$PREFIX" -n -o $ODIR --thread=shallow --cover-letter $RELATIVE_TO..$COMMIT_ID > /dev/null
+if [ -z "$IN_REPLY_TO" ]; then
+    git format-patch $extraopts -M40 --subject-prefix="$PREFIX" -n -o $ODIR --thread=shallow --in-reply-to="$IN_REPLY_TO" --cover-letter $RELATIVE_TO..$COMMIT_ID > /dev/null
+else
+    git format-patch $extraopts -M40 --subject-prefix="$PREFIX" -n -o $ODIR --thread=shallow --cover-letter $RELATIVE_TO..$COMMIT_ID > /dev/null
+fi
 
 if [ -z "$(ls -A $ODIR 2> /dev/null)" ]; then
     echo "ERROR: $ODIR is empty, no cover letter and patches was generated!"