--- /dev/null
+#!/bin/bash
+#
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+set -e
+
+SELF="$(basename $0)"
+SELF="${SELF/-/ }"
+
+STATE_FILE=".git/REPLAY_MERGE"
+
+die() {
+ for MESSAGE in "$@"; do
+ echo -e "${MESSAGE}" >&2
+ done
+ exit 1
+}
+
+die_with_usage() {
+ die "Usage:" \
+ "" \
+ " ${SELF} <merge_commit_id> <target_remote> <target_branch>" \
+ " ${SELF} --continue" \
+ " ${SELF} --abort"
+}
+
+die_with_continue_instructions() {
+ die "" \
+ "Replay interrupted. Conflicts need to be fixed manually." \
+ "When done, run \"${SELF} --continue\"." \
+ "Use \"${SELF} --abort\" to abort the replay."
+}
+
+die_if_wrong_dir() {
+ if [[ ! -d ".git" ]]; then
+ die "You need to run this command from the toplevel of the working tree."
+ fi
+}
+
+die_if_not_in_progress() {
+ die_if_wrong_dir
+ if [[ ! -f "${STATE_FILE}" ]]; then
+ die "No replay-merge in progress?"
+ fi
+}
+
+die_if_in_progress() {
+ die_if_wrong_dir
+ if [[ -f "${STATE_FILE}" ]]; then
+ die "Another replay-merge in progress. Use --continue or --abort."
+ fi
+}
+
+die_if_local_behind_target() {
+ TARGET_REF_HEAD="$(git rev-list --max-count=1 "${TARGET_REF}")"
+ if [[ "$(git merge-base "${TARGET_REF}" "${TARGET_BRANCH}")" != "${TARGET_REF_HEAD}" ]]; then
+ die "Local branch ${TARGET_BRANCH} is behind ${TARGET_REF}, cannot merge into it." \
+ "Update or remove the local branch, then run \"${SELF} --continue\"." \
+ "Use \"${SELF} --abort\" to abort the replay."
+ fi
+}
+
+branch_exists() {
+ ESCAPED_BRANCH_NAME=${1//\//\\\/}
+ BRANCH_REGEX="/^(remotes\/)?${ESCAPED_BRANCH_NAME}$/"
+ if [[ -n "$(git branch -a | awk "\$NF ~ ${BRANCH_REGEX} {print \$NF}")" ]]; then
+ return 0
+ else
+ return 1
+ fi
+}
+
+go() {
+ # Process parameters.
+ SOURCE_COMMIT="$1"
+ TARGET_REMOTE="$2"
+ TARGET_BRANCH="$3"
+ TARGET_REF="${TARGET_REMOTE}/${TARGET_BRANCH}"
+ # Establish the range of commits comprising the source branch.
+ REPLAY_COMMIT_RANGE="$(
+ git show --format="%P" "${SOURCE_COMMIT}" 2>&1 |
+ sed -n "1s/\([0-9a-f]\{40\}\) \([0-9a-f]\{40\}\)/\1..\2/p;"
+ )"
+ if [[ -z "${REPLAY_COMMIT_RANGE}" ]]; then
+ die "${SOURCE_COMMIT} is not a valid merge commit ID."
+ fi
+ # Extract the name of the source branch.
+ SOURCE_BRANCH="$(
+ git log --max-count=1 --format="%B" "${SOURCE_COMMIT}" |
+ sed -n "s/^Merge branch '\([^'][^']*\).*/\1/p;" |
+ head -n 1
+ )"
+ if [[ -z "${SOURCE_BRANCH}" ]]; then
+ die "Unable to extract source branch name from ${SOURCE_COMMIT}."
+ fi
+ # Ensure the target ref is valid.
+ if ! branch_exists "${TARGET_REF}"; then
+ die "${TARGET_REF} is not a valid replay target."
+ fi
+ # Abort if a local branch with the name about to be used for replaying
+ # the merge already exists.
+ REPLAY_BRANCH="${SOURCE_BRANCH}-${TARGET_BRANCH}"
+ if branch_exists "${REPLAY_BRANCH}"; then
+ die "Local branch with name ${REPLAY_BRANCH} already exists." \
+ "Cannot use it for replaying a merge."
+ fi
+ # Get the name of the currently checked out branch so that it can be
+ # checked out again once the replay is finished.
+ CHECKED_OUT_BRANCH="$(git branch | awk "\$1 == \"*\" {print \$2}")"
+ # Store state in case it needs to be restored later.
+ cat <<-EOF > "${STATE_FILE}"
+ CHECKED_OUT_BRANCH="${CHECKED_OUT_BRANCH}"
+ SOURCE_COMMIT="${SOURCE_COMMIT}"
+ SOURCE_BRANCH="${SOURCE_BRANCH}"
+ REPLAY_BRANCH="${REPLAY_BRANCH}"
+ TARGET_REMOTE="${TARGET_REMOTE}"
+ TARGET_BRANCH="${TARGET_BRANCH}"
+ TARGET_REF="${TARGET_REF}"
+ EOF
+ # Announce the plan.
+ echo "Attempting to replay ${REPLAY_COMMIT_RANGE} on top of ${TARGET_REF} in ${REPLAY_BRANCH}..."
+ # Switch to the replay branch.
+ git checkout -t -b "${REPLAY_BRANCH}" "${TARGET_REF}" >/dev/null
+ # Try replaying the branch. If there is any conflict, the command will
+ # fail, which means we need to bail and let the user fix the current
+ # cherry-pick manually, expecting "git replay-merge --continue" to be
+ # used afterwards. If there is no conflict, just proceed with what
+ # --continue would do.
+ if ! git cherry-pick -x "${REPLAY_COMMIT_RANGE}"; then
+ die_with_continue_instructions
+ fi
+ resume
+}
+
+resume() {
+ # If cherry-picking has not yet been completed, resume it. If it
+ # fails, bail. If if succeeds, we can proceed with merging.
+ if [[ -f ".git/sequencer/todo" ]]; then
+ if ! git cherry-pick --continue; then
+ die_with_continue_instructions
+ fi
+ fi
+ # Announce the plan.
+ echo "Attempting to merge ${REPLAY_BRANCH} into ${TARGET_BRANCH}..."
+ # Check if a local branch with the same name as the target branch
+ # exists. If it does not, switch to a new local branch with the same
+ # name as the target branch. Otherwise, ensure the local branch is not
+ # behind the target branch at the target remote, then switch to it.
+ if ! branch_exists "${TARGET_BRANCH}"; then
+ git checkout -t -b "${TARGET_BRANCH}" "${TARGET_REF}" >/dev/null
+ else
+ die_if_local_behind_target
+ git checkout "${TARGET_BRANCH}" &>/dev/null
+ fi
+ # Use the original commit message with a modified subject line.
+ COMMIT_MSG="$(
+ git log --max-count=1 --format="%B" "${SOURCE_COMMIT}" |
+ sed "1s/.*/Merge branch '${REPLAY_BRANCH}' into '${TARGET_BRANCH}'/;"
+ )"
+ # Merge the replay branch into the local target branch.
+ git merge --no-ff -m "${COMMIT_MSG}" "${REPLAY_BRANCH}"
+ cat <<-EOF
+
+ Replayed ${SOURCE_BRANCH} onto ${TARGET_BRANCH}.
+ To push the replay, use:
+
+ git push ${TARGET_REMOTE} ${TARGET_BRANCH}:${TARGET_BRANCH}
+
+ EOF
+ cleanup
+}
+
+cleanup() {
+ # Restore working copy state from before the replay was started,
+ # ignoring any potential errors to prevent "set -e" from interfering.
+ {
+ git merge --abort
+ git cherry-pick --abort
+ git checkout "${CHECKED_OUT_BRANCH}"
+ git branch -D "${REPLAY_BRANCH}"
+ } &>/dev/null || true
+ rm -f "${STATE_FILE}"
+}
+
+case "$1" in
+ "--abort")
+ die_if_not_in_progress
+ source "${STATE_FILE}"
+ cleanup
+ ;;
+ "--continue")
+ die_if_not_in_progress
+ source "${STATE_FILE}"
+ resume
+ ;;
+ *)
+ if [[ $# -ne 3 ]]; then
+ die_with_usage
+ fi
+ die_if_in_progress
+ go "$@"
+ ;;
+esac
projects / thirdparty / bind9.git / commitdiff
