Function cbm_setenv

src/foundation/compat.h:135–166

/* ── setenv / unsetenv (Windows lacks them) ──────────────────── */
#ifdef _WIN32
static inline int cbm_setenv(const char *name, const char *value, int overwrite) {
    (void)overwrite;
    if (!name || !value) {
        return EINVAL;
    }
    int name_chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, name, -1, NULL, 0);
    int value_chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, value, -1, NULL, 0);
    wchar_t *wide_name =
        name_chars > 0 ? (wchar_t *)malloc((size_t)name_chars * sizeof(*wide_name)) : NULL;
    wchar_t *wide_value =
        value_chars > 0 ? (wchar_t *)malloc((size_t)value_chars * sizeof(*wide_value)) : NULL;
    bool converted =
        wide_name && wide_value &&
        MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, name, -1, wide_name, name_chars) > 0 &&
        MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, value, -1, wide_value, value_chars) > 0;
    if (!converted) {
        free(wide_name);
        free(wide_value);
        return EINVAL;
    }
    /* Keep the CRT's narrow environment useful for legacy getenv callers,
     * then repair the process-wide Windows environment with the actual UTF-16
     * value. _putenv_s alone routes UTF-8 path bytes through the active ANSI
     * code page, which corrupts non-ASCII cache roots inherited by children. */
    int status = _putenv_s(name, value);
    if (status == 0 && !SetEnvironmentVariableW(wide_name, wide_value)) {
        status = EINVAL;
    }
    free(wide_name);
    free(wide_value);
    return status;
}
static inline int cbm_unsetenv(const char *name) {
    if (!name) {
        return EINVAL;