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diff --git a/scripts/git/git-merge-forward.sh b/scripts/git/git-merge-forward.sh
new file mode 100755
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+++ b/scripts/git/git-merge-forward.sh
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+#!/usr/bin/env bash
+
+SCRIPT_NAME=$(basename "$0")
+
+function usage()
+{
+  echo "$SCRIPT_NAME [-h] [-n] [-t <test-branch-prefix> [-u]]"
+  echo
+  echo "  arguments:"
+  echo "   -h: show this help text"
+  echo "   -n: dry run mode"
+  echo "       (default: run commands)"
+  echo "   -t: test branch mode: create new branches from the commits checked"
+  echo "       out in each maint directory. Call these branches prefix_035,"
+  echo "       prefix_040, ... , prefix_master."
+  echo "       (default: merge forward maint-*, release-*, and master)"
+  echo "   -u: in test branch mode, if a prefix_* branch already exists,"
+  echo "       skip creating that branch. Use after a merge error, to"
+  echo "       restart the merge forward at the first unmerged branch."
+  echo "       (default: if a prefix_* branch already exists, fail and exit)"
+  echo
+  echo " env vars:"
+  echo "   required:"
+  echo "   TOR_FULL_GIT_PATH: where the git repository directories reside."
+  echo "       You must set this env var, we recommend \$HOME/git/"
+  echo "       (default: fail if this env var is not set;"
+  echo "       current: $GIT_PATH)"
+  echo
+  echo "   optional:"
+  echo "   TOR_MASTER: the name of the directory containing the tor.git clone"
+  echo "       The tor master git directory is \$GIT_PATH/\$TOR_MASTER"
+  echo "       (default: tor; current: $TOR_MASTER_NAME)"
+  echo "   TOR_WKT_NAME: the name of the directory containing the tor"
+  echo "       worktrees. The tor worktrees are:"
+  echo "       \$GIT_PATH/\$TOR_WKT_NAME/{maint-*,release-*}"
+  echo "       (default: tor-wkt; current: $TOR_WKT_NAME)"
+  echo "   we recommend that you set these env vars in your ~/.profile"
+}
+
+#################
+# Configuration #
+#################
+
+# Don't change this configuration - set the env vars in your .profile
+
+# Where are all those git repositories?
+GIT_PATH=${TOR_FULL_GIT_PATH:-"FULL_PATH_TO_GIT_REPOSITORY_DIRECTORY"}
+# The tor master git repository directory from which all the worktree have
+# been created.
+TOR_MASTER_NAME=${TOR_MASTER_NAME:-"tor"}
+# The worktrees location (directory).
+TOR_WKT_NAME=${TOR_WKT_NAME:-"tor-wkt"}
+
+##########################
+# Git branches to manage #
+##########################
+
+# The branches and worktrees need to be modified when there is a new branch,
+# and when an old branch is no longer supported.
+
+# Configuration of the branches that needs merging. The values are in order:
+#   (0) current maint/release branch name
+#   (1) previous maint/release name to merge into (0)
+#         (only used in merge forward mode)
+#   (2) Full path of the git worktree
+#   (3) current branch suffix
+#         (maint branches only, only used in test branch mode)
+#   (4) previous test branch suffix to merge into (3)
+#         (maint branches only, only used in test branch mode)
+#
+# Merge forward example:
+#   $ cd <PATH/TO/WORKTREE> (2)
+#   $ git checkout maint-0.3.5 (0)
+#   $ git pull
+#   $ git merge maint-0.3.4 (1)
+#
+# Test branch example:
+#   $ cd <PATH/TO/WORKTREE> (2)
+#   $ git checkout -b ticket99999_035 (3)
+#   $ git checkout maint-0.3.5 (0)
+#   $ git pull
+#   $ git checkout ticket99999_035
+#   $ git merge maint-0.3.5
+#   $ git merge ticket99999_034 (4)
+#
+# First set of arrays are the maint-* branch and then the release-* branch.
+# New arrays need to be in the WORKTREE= array else they aren't considered.
+#
+# Only used in test branch mode
+# We create a test branch for the earliest maint branch.
+# But it's the earliest maint branch, so we don't merge forward into it.
+# Since we don't merge forward into it, the second and fifth items must be
+# blank ("").
+
+# origin that will be used to fetch the updates. All the worktrees are created
+# from that repository.
+ORIGIN_PATH="$GIT_PATH/$TOR_MASTER_NAME"
+
+#######################
+# Argument processing #
+#######################
+
+# Controlled by the -n option. The dry run option will just output the command
+# that would have been executed for each worktree.
+DRY_RUN=0
+
+# Controlled by the -t <test-branch-prefix> option. The test branch base
+# name option makes git-merge-forward.sh create new test branches:
+# <tbbn>_035, <tbbn>_040, ... , <tbbn>_master, and merge forward.
+TEST_BRANCH_PREFIX=
+
+# Controlled by the -u option. The use existing option checks for existing
+# branches with the <test-branch-prefix>, and checks them out, rather than
+# creating a new branch.
+USE_EXISTING=0
+
+while getopts "hnt:u" opt; do
+  case "$opt" in
+    h) usage
+       exit 0
+       ;;
+    n) DRY_RUN=1
+       echo "    *** DRY RUN MODE ***"
+       ;;
+    t) TEST_BRANCH_PREFIX="$OPTARG"
+       echo "    *** CREATING TEST BRANCHES: ${TEST_BRANCH_PREFIX}_nnn ***"
+       ;;
+    u) USE_EXISTING=1
+       echo "    *** USE EXISTING TEST BRANCHES MODE ***"
+       ;;
+    *)
+       echo
+       usage
+       exit 1
+       ;;
+  esac
+done
+
+###########################
+# Git worktrees to manage #
+###########################
+
+set -e
+if [ -z "$TEST_BRANCH_PREFIX" ]; then
+  # maint/release merge mode
+  eval "$(git-list-tor-branches.sh -m)"
+  # Remove first element: we don't merge forward into it.
+  WORKTREE=( "${WORKTREE[@]:1}" )
+else
+  eval "$(git-list-tor-branches.sh -m -R)"
+fi
+set +e
+
+COUNT=${#WORKTREE[@]}
+
+#############
+# Constants #
+#############
+
+# Control characters
+CNRM=$'\x1b[0;0m'   # Clear color
+
+# Bright color
+BGRN=$'\x1b[1;32m'
+BBLU=$'\x1b[1;34m'
+BRED=$'\x1b[1;31m'
+BYEL=$'\x1b[1;33m'
+IWTH=$'\x1b[3;37m'
+
+# Strings for the pretty print.
+MARKER="${BBLU}[${BGRN}+${BBLU}]${CNRM}"
+SUCCESS="${BGRN}success${CNRM}"
+FAILED="${BRED}failed${CNRM}"
+
+####################
+# Helper functions #
+####################
+
+# Validate the given returned value (error code), print success or failed. The
+# second argument is the error output in case of failure, it is printed out.
+# On failure, this function exits.
+function validate_ret
+{
+  if [ "$1" -eq 0 ]; then
+    printf "%s\\n" "$SUCCESS"
+  else
+    printf "%s\\n" "$FAILED"
+    printf "    %s" "$2"
+    exit 1
+  fi
+}
+
+# Switch to the given branch name.
+function switch_branch
+{
+  local cmd="git checkout '$1'"
+  printf "  %s Switching branch to %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Checkout a new branch with the given branch name.
+function new_branch
+{
+  local cmd="git checkout -b '$1'"
+  printf "  %s Creating new branch %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Switch to an existing branch, or checkout a new branch with the given
+# branch name.
+function switch_or_new_branch
+{
+  local cmd="git rev-parse --verify '$1'"
+  if [ $DRY_RUN -eq 0 ]; then
+    # Call switch_branch if there is a branch, or new_branch if there is not
+    msg=$( eval "$cmd" 2>&1 )
+    RET=$?
+    if [ $RET -eq 0 ]; then
+      # Branch: (commit id)
+      switch_branch "$1"
+    elif [ $RET -eq 128 ]; then
+      # Not a branch: "fatal: Needed a single revision"
+      new_branch "$1"
+    else
+      # Unexpected return value
+      validate_ret $RET "$msg"
+    fi
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}, then depending on the result:"
+    switch_branch "$1"
+    new_branch "$1"
+  fi
+}
+
+# Pull the given branch name.
+function pull_branch
+{
+  local cmd="git pull"
+  printf "  %s Pulling branch %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Merge the given branch name ($1) into the current branch ($2).
+function merge_branch
+{
+  local cmd="git merge --no-edit '$1'"
+  printf "  %s Merging branch %s into %s..." "$MARKER" "$1" "$2"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Merge origin/(branch name) into the current branch.
+function merge_branch_origin
+{
+  local cmd="git merge --ff-only 'origin/$1'"
+  printf "  %s Merging branch origin/%s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+# Go into the worktree repository.
+function goto_repo
+{
+  if [ ! -d "$1" ]; then
+    echo "  $1: Not found. Stopping."
+    exit 1
+  fi
+  cd "$1" || exit
+}
+
+# Fetch the origin. No arguments.
+function fetch_origin
+{
+  local cmd="git fetch origin"
+  printf "  %s Fetching origin..." "$MARKER"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
+###############
+# Entry point #
+###############
+
+# First, fetch the origin.
+goto_repo "$ORIGIN_PATH"
+fetch_origin
+
+# Go over all configured worktree.
+for ((i=0; i<COUNT; i++)); do
+  current=${!WORKTREE[$i]:0:1}
+  previous=${!WORKTREE[$i]:1:1}
+  repo_path=${!WORKTREE[$i]:2:1}
+  # default to merge forward mode
+  test_current=
+  test_previous=
+  target_current="$current"
+  target_previous="$previous"
+  if [ "$TEST_BRANCH_PREFIX" ]; then
+    test_current_suffix=${!WORKTREE[$i]:3:1}
+    test_current=${TEST_BRANCH_PREFIX}${test_current_suffix}
+    # the current test branch, if present, or maint/release branch, if not
+    target_current="$test_current"
+    test_previous_suffix=${!WORKTREE[$i]:4:1}
+    if [ "$test_previous_suffix" ]; then
+      test_previous=${TEST_BRANCH_PREFIX}${test_previous_suffix}
+      # the previous test branch, if present, or maint/release branch, if not
+      target_previous="$test_previous"
+    fi
+  fi
+
+  printf "%s Handling branch \\n" "$MARKER" "${BYEL}$target_current${CNRM}"
+
+  # Go into the worktree to start merging.
+  goto_repo "$repo_path"
+  if [ "$test_current" ]; then
+    if [ $USE_EXISTING -eq 0 ]; then
+      # Create a test branch from the currently checked-out branch/commit
+      # Fail if it already exists
+      new_branch "$test_current"
+    else
+      # Switch if it exists, or create if it does not
+      switch_or_new_branch "$test_current"
+    fi
+  fi
+  # Checkout the current maint/release branch
+  switch_branch "$current"
+  # Update the current maint/release branch with an origin merge to get the
+  # latest updates
+  merge_branch_origin "$current"
+  if [ "$test_current" ]; then
+    # Checkout the test branch
+    switch_branch "$test_current"
+    # Merge the updated maint branch into the test branch
+    merge_branch "$current" "$test_current"
+  fi
+  # Merge the previous branch into the target branch
+  # Merge Forward Example:
+  #   merge maint-0.3.5 into maint-0.4.0.
+  # Test Branch Example:
+  #   merge bug99999_035 into bug99999_040.
+  # Skip the merge if the previous branch does not exist
+  # (there's nothing to merge forward into the oldest test branch)
+  if [ "$target_previous" ]; then
+    merge_branch "$target_previous" "$target_current"
+  fi
+done