pick-to-branch

#! /usr/bin/env bash

function usage {
    echo "Usage: pick-to-branch [<id> | h | HEAD ] <target> [<num>]

    Cherry-pick a commit (or <num> commits) on the given target release branch.
    If this is not the current branch, the current branch and its state are preserved.

    The optional <id> arg specifies the ID of the (last) commit to cherry-pick.
    It can also be given in the form of a branch name.  If 'h' or 'HEAD'
    or no <id> arg is given, the commit id of the HEAD of the master is used.

    The <target> arg must match a release branch or start with 'm' for master.
    A release branch may be given simply as 102, 110, 111, 30, 31.

    The optional <num> argument specifies the number of commits to cherry-pick.
    It defaults to 1 and can be specified only in case <id> is also given."
}

num=1

case $# in
3)
    id=$1
    b=$2
    num=$3
    ;;
2)
    id=$1
    b=$2
    ;;
1)
    id=`git show -s --format="%H" master`
    b=$1
    ;;
*)
    usage
    exit 1
    ;;
esac

case $id in
    h|HEAD) id=`git show -s --format="%H" master`;;
esac


case $b in
*1*0*2*)
    TARGET=OpenSSL_1_0_2-stable
    ;;
*1*1*1*)
    TARGET=OpenSSL_1_1_1-stable
    ;;
*3*0*)
    TARGET=openssl-3.0
    ;;
*3*1*)
    TARGET=openssl-3.1
    ;;
*3*2*)
    TARGET=openssl-3.2
    ;;
*3*3*)
    TARGET=openssl-3.3
    ;;
*3*4*)
    TARGET=openssl-3.4
    ;;
m*)
    TARGET=master
    ;;
*)
    echo Unknown target release branch \'$b\'
    exit 1
    ;;
esac

REMOTE=$(git for-each-ref --format='%(push:remotename)' \
             $(git rev-parse --symbolic-full-name $TARGET))
# usually this will be 'upstream'
if [ "$REMOTE" = "" ] ; then
    echo Cannot find git remote for target branch $TARGET
    exit 1
fi
git remote get-url $REMOTE | grep -q 'github.openssl.org:' \
 || echo -e "WARNING: URL of remote '$REMOTE' of target branch '$TARGET' does not match 'github.openssl.org'\n"

echo "Target remote and branch is: $REMOTE/$TARGET"
echo "First commit to cherry-pick is: $id~$((num - 1))"
echo "Number of commits to pick: $num"
echo
echo "Commit(s) to be cherry-picked:"
git log $id~$num..$id
echo

echo -n "Press Enter to continue, Ctrl-C to abort: "; read foo

ORIG_REF=`git rev-parse --abbrev-ref HEAD` # usually this will be 'master'
if [ "$TARGET" != "$ORIG_REF" ]; then
    STASH_OUT=`git stash`
fi

function cleanup {
    rv=$?
    echo # make sure to enter new line, needed, e.g., after Ctrl-C
    [ $rv -ne 0 ] && echo -e "pick-to-branch failed"
    if [ "$CHERRYPICKING" == 1 ] ; then
        echo "cherry-picking failed - maybe did not provide a suitable <num> argument?"
        git cherry-pick --abort 2>/dev/null || true
    fi
    if [ "$ORIG_TARGET_HEAD" != "" ]; then
        echo Restoring original commit HEAD of $TARGET
        git reset --merge "$ORIG_TARGET_HEAD"
    fi
    if [ "$TARGET" != "$ORIG_REF" ]; then
        echo Returning to previous branch $ORIG_REF
        git checkout -q $ORIG_REF
        if [ "$STASH_OUT" != "No local changes to save" ]; then
            git stash pop -q # restore original state, pruning any leftover commits added locally
        fi
    fi
}
set -o errexit
trap 'cleanup' EXIT

git checkout --quiet master
git checkout $TARGET
ORIG_TARGET_HEAD=`git show -s --format="%H"`
git pull --ff-only `git rev-parse --abbrev-ref  @{u} | sed "s|/| |"`
CHERRYPICKING=1
git cherry-pick -e -x $id~$num..$id || (echo -ne "Press Ctrl-d to abort, or fix the issue in another shell,\n    run 'git cherry-pick --continue' there, and on success press Enter here: "; read || exit 1)
CHERRYPICKING=

echo
while true ; do
    echo -n "Enter 'y'/'yes' to push or 'n'/'no' to abort: "
    read x
    x="`echo $x | tr A-Z a-z`"
    if [ "$x" = "y" -o "$x" = "yes" -o "$x" = "n" -o "$x" = "no" ]
    then
        break
    fi
done

if [ "$x" = "y" -o "$x" = "yes" ] ; then
    git push
    ORIG_TARGET_HEAD=
fi