request-pull: use the annotated tag contents

The integrator tool will start allowing to pull a signed or an annotated
tag, i.e.

    $ git pull $there tags/for-linus

and the description in the tag is used to convey a meaningful message from
the lieutenant to the integrator to justify the history being pulled.

Include the message in the pull request e-mail, as the same information is
useful in this context, too. It would encourage the lieutenants to write
meaningful messages in their signed tags.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-request-pull.sh

@@ -48,6 +48,8 @@ then
 	fi
 fi
 
+tag_name=$(git describe --exact "$head^0" 2>/dev/null)
+
 test -n "$base" && test -n "$url" || usage
 baserev=$(git rev-parse --verify "$base"^0) &&
 headrev=$(git rev-parse --verify "$head"^0) || exit
@@ -82,8 +84,20 @@ then
 	echo "(from the branch description for $branch local branch)"
 	echo
 	git config "branch.$branch_name.description"
+fi &&
+
+if test -n "$tag_name"
+then
+	git cat-file tag "$tag_name" |
+	sed -n -e '1,/^$/d' -e '/^-----BEGIN PGP /q' -e p
+	echo
+fi &&
+
+if test -n "$branch_name" || test -n "$tag_name"
+then
 	echo "----------------------------------------------------------------"
 fi &&
+
 git shortlog ^$baserev $headrev &&
 git diff -M --stat --summary $patch $merge_base..$headrev || status=1
 

t/t5150-request-pull.sh

@@ -86,6 +86,7 @@ test_expect_success 'setup: two scripts for reading pull requests' '
 	s/$downstream_url_for_sed/URL/g
 	s/for-upstream/BRANCH/g
 	s/mnemonic.txt/FILENAME/g
+	s/^version [0-9]/VERSION/
 	/^ FILENAME | *[0-9]* [-+]*\$/ b diffstat
 	/^AUTHOR ([0-9]*):\$/ b shortlog
 	p
@@ -200,6 +201,9 @@ test_expect_success 'pull request format' '
 
 	  SUBJECT (DATE)
 
+	----------------------------------------------------------------
+	VERSION
+
 	----------------------------------------------------------------
 	SHORTLOG