"git submodule update --init --recursive" with second change for submodules referencing unpushed code (alternative URIs for submodules)

submodule_update_alturl.sh

#!/bin/bash
script_version="1.04"

unset CDPATH

if [[ $1 = "--help" ]]; then
    echo >&2 "Script version: $script_version"
    echo >&2 "Expected environment example: ALTURL_repo1name=https://github.com/user1/repo1name.git  ALTURL_repo2name=https://github.com/user1/repo2name.git ..."
    echo >&2 "Expected environment example: mangle_submodule_name() - it should mangle its argument: 'repo/1/name' -> 'repo_1_name'"
    echo >&2 "Expected environment example: submodule_recurse_script=update-checkout.sh submodule_recurse_arguments='arg1 arg2 arg3'"
    echo >&2 "Script arguments: --force - optional argument for passing to embedded 'git submodule update' command"
    exit 1
fi

cd_to_toplevel () {
    cdup=$(git rev-parse --show-toplevel) &&
    cd "$cdup" || {
        echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
        exit 1
    }
}

cd_to_toplevel

set -e
#set -x

list_all_submodule_names() {
    # output for submodule "Sub.path.Name" for command git config -f .gitmodules --list:
    #submodule.Sub.path.Name.path=Sub/path/Name
    #submodule.Sub.path.Name.url=git@domain:group/repo.git
    git config -f .gitmodules --list | \
        grep '^submodule\.' | sed 's/^submodule\.//' | sed 's/\.[^\.]\{1,\}=.\{1,\}$//' | sort | uniq
}

handle_submodules_in_current_directory() {
    if [ ! -f .gitmodules ]; then return 0; fi

    #git submodule init
    #git submodule sync || true

    IFS='
'
    local submodule_list=($(list_all_submodule_names))

    for MODULE_NAME in "${submodule_list[@]}"; do
        local MANGLED_MODULE_NAME=$(mangle_submodule_name "${MODULE_NAME}")
        printf 'Processing submodule %-15s %-20s in\t %s\n' "${MANGLED_MODULE_NAME}" "($MODULE_NAME)" "$PWD"
        local SP=$(git config -f .gitmodules --get submodule."$MODULE_NAME".path || true)
        if [ -z $SP ]; then SP="$MODULE_NAME"; fi

        # First time trying without hacks
        if git submodule update --init "$@" -- "$SP" ; then
            # OK, no need for tricks
            :;
        else
            local ADDITIONAL_URL_NAME=ALTURL_${MANGLED_MODULE_NAME}
            local ADDITIONAL_URL=$(eval "echo \"\$$ADDITIONAL_URL_NAME\"")
            if [ -n "$ADDITIONAL_URL" ]; then
                echo "Trying alternative URL: $ADDITIONAL_URL"
                git -C "$SP" fetch "$ADDITIONAL_URL" '+refs/heads/*:refs/remotes/alturl/*' '+refs/tags/*:refs/tags/alturl/*'
            else
                echo "No alternative URL for $MODULE_NAME"
                echo "Use $ADDITIONAL_URL_NAME environment variable to give it a second chance"
                exit 1
            fi
            # Now retry
            git submodule update "$@" -- "$SP"
        fi

        # go deeper:
        if [[ ! -z $submodule_recurse_script && -f "$SP/$submodule_recurse_script" ]]; then
            echo "Entering $SP to update its submodules (its own script)"
            echo "===================================== (caller pid: $$)"
            (
                cd "$SP"
                "./$submodule_recurse_script" $submodule_recurse_arguments
            )
            echo "===================================== (caller pid: $$)"
            echo "Leaving $SP"
        elif [ -f "$SP/.gitmodules" ]; then
            echo "Entering $SP to update its submodules (subproc)"
            (
                cd "$SP"
                handle_submodules_in_current_directory
            )
            echo "Leaving $SP"
        fi
    done
}

handle_submodules_in_current_directory