fixup! BB 42305: Add script to combine translation files across versions.

        )

def get_stable_branch(

    compare_version: BrowserBranch,

) -> tuple[BrowserBranch, BrowserBranch | None]:

def get_stable_branch(compare_version: BrowserBranch) -> BrowserBranch:

    """Find the most recent stable branch in the origin repository.

    :param compare_version: The development branch to compare against.

    :returns: The stable and legacy branches. If no legacy branch is found,

      `None` will be returned instead.

    :returns: The stable branch.

    """

    # We search for build1 tags. These are added *after* the rebase of browser

    # commits, so the corresponding branch should contain our strings.

        fetch_args = ("--depth=1", "--filter=object:type=tag")

    git_run(["fetch", *fetch_args, "origin", "tag", tag_glob])

    stable_branches = []

    legacy_branches = []

    stable_annotation_regex = re.compile(r"\bstable\b")

    legacy_annotation_regex = re.compile(r"\blegacy\b")

    tag_pattern = re.compile(

        rf"^{re.escape(compare_version.prefix)}-[^-]+-[^-]+-[^-]+-build1$"

    )

    ):

        if not tag_pattern.match(build_tag):

            continue

        is_stable = bool(stable_annotation_regex.search(annotation))

        is_legacy = bool(legacy_annotation_regex.search(annotation))

        if not is_stable and not is_legacy:

        if not stable_annotation_regex.search(annotation):

            continue

        try:

            # Branch name is the same as the tag, minus "-build1".

            continue

        if branch.prefix != compare_version.prefix:

            continue

        if is_stable:

        # Stable can be one release version behind.

        # NOTE: In principle, when switching between versions there may be a

        # window of time where the development branch has not yet progressed

        if release_diff < 0.0 or release_diff > 1.0:

            continue

        stable_branches.append(branch)

        elif is_legacy:

            # Legacy can be arbitrary release versions behind.

            legacy_branches.append(branch)

    if not stable_branches:

        raise Exception("No stable build1 branch found")

    return (

    # Return the stable branch with the highest version.

        max(stable_branches),

        max(legacy_branches) if legacy_branches else None,

    )

    return max(stable_branches)

current_branch = BrowserBranch(args.current_branch, is_head=True)

stable_branch, legacy_branch = get_stable_branch(current_branch)

if os.environ.get("TRANSLATION_INCLUDE_LEGACY", "") != "true":

    legacy_branch = None

stable_branch = get_stable_branch(current_branch)

files_list = []

        f"Will be unused in {current_branch.browser_version_name}!",

    )

    if legacy_branch and not file_dict.get("exclude-legacy", False):

        legacy_file = legacy_branch.get_file(name, where_dirs)

        if legacy_file is not None and current_file is None and stable_file is None:

            logger.warning(f"{name} still exists in the legacy branch")

        elif legacy_file is None:

            logger.warning(f"{name} does not exist in the legacy branch")

        elif stable_file is not None and legacy_file.path != stable_file.path:

            logger.warning(

                f"{name} has different paths in the stable and legacy branch. "

                f"{stable_file.path} : {legacy_file.path}"

            )

        elif current_file is not None and legacy_file.path != current_file.path:

            logger.warning(

                f"{name} has different paths in the current and legacy branch. "

                f"{current_file.path} : {legacy_file.path}"

            )

        content = combine_files(

            name,

            content,

            legacy_file.content,

            f"Unused in {stable_branch.browser_version_name}!",

        )

    elif legacy_branch:

        logger.info(f"Excluding legacy branch for {name}")

    files_list.append({

        "name": name,

        # If "directory" is unspecified, we place the file directly beneath

    "files": files_list,

}

if legacy_branch:

    json_data["legacy-branch"] = legacy_branch.name

with open(args.outname, "w") as file:

    json.dump(json_data, file)