pacman-helper.sh: compose release body/notes

Do some trivial sed escaping of characters that might cause issues in
JSON.  This is not comprehensive, but the text in question is controlled
by this script and package names and versions being published, so we can
reasonably be assured of a limited set of characters being used.  (In
fact, it's probably unnecessary to escape quotes and backslashes).   

Co-authored-by: Johannes Schindelin <[email protected]>
Signed-off-by: Jeremy Drake <[email protected]>

Author: jeremyd2019

pacman-helper.sh

@@ -349,6 +349,7 @@ quick_action () { # <action> <file>...
 	test -z "$GPGKEY" || sign_option=--sign
 	dbs=
 	to_push=
+	>release_notes.txt
 	for arch in $architectures
 	do
 		eval "msys=\$${arch}_msys"
@@ -454,11 +455,16 @@ quick_action () { # <action> <file>...
 				$(printf '%s\n' $msys $mingw | wc -l) \
 				"$(printf '%s\n' $msys $mingw |
 					sed 's/^\(.*\)-\([^-]*-[^-]*\)-[^-]*\.pkg\.tar\.\(xz\|zst\)$/\1 -> \2/')")"
+			printf '%s\n' $msys $mingw |
+			sed 's/^\(.*\)-\([^-]*-[^-]*\)-[^-]*\.pkg\.tar\.\(xz\|zst\)$/* \1 -> \2/' >>release-notes.txt
 			;;
 		 remove)
 			 msg="$(printf 'Remove %s package(s)\n\n%s\n' \
 				$(printf '%s\n' $msys $mingw | wc -l) \
 				"$(printf '%s\n' $msys $mingw)")"
+			printf '%s\n' $msys $mingw |
+			sed 's/^/* dropped /' >>release-notes.txt
+			;;
 		 esac &&
 		 git commit -asm "$msg") ||
 		die "Could not ${label} $msys $mingw to/from db in $arch"
@@ -545,8 +551,9 @@ quick_action () { # <action> <file>...
 	then
 		echo "Would create a GitHub Release '$tagname' at git-for-windows/pacman-repo" >&2
 	else
+		body="$(sed -z 's/[\"]/\\&/g;s/\n/\\n/g' release-notes.txt)"
 		id="$(curl -H "Authorization: Bearer $GITHUB_TOKEN" -sfL --show-error -XPOST -d \
-			'{"tag_name":"'"$tagname"'","name":"'"$tagname"'","draft":true,"prerelease":true}' \
+			'{"tag_name":"'"$tagname"'","name":"'"$tagname"'","body":"'"$body"'","draft":true,"prerelease":true}' \
 			"https://api.github.com/repos/git-for-windows/pacman-repo/releases" |
 		sed -n 's/^  "id": *\([0-9]*\).*/\1/p')"
 	fi ||