Cannot determine HOSTNAME in 4.0.6?

Something was changed between 4.0.5 and 4.0.6 and now there is no way to determine the host name of the local host from a PHP script when executed in Apache. The output of phpinfo shows that the HOSTNAME environment variable that existed in 4.0.5 is not available in 4.0.6. This affects the return value of getenv and the contents of HTTP_ENV_VARS. Is this a bug or a feature? Here are the variables listed in the Environment section of Additional Modules as output from phpinfo on two of my servers, one with 4.0.5 and one with 4.0.6. 4.0.5 ----- LESSOPEN USERNAME ENV HISTSIZE HOSTNAME LOGNAME MAIL TERM HOSTTYPE PATH HOME INPUTRC SHELL USER LANG OSTYPE SHLVL LS_COLORS _ 4.0.6 ----- INIT_VERSION previous TERM HOSTTYPE PATH CONSOLE HOME PREVLEVEL RUNLEVEL SHELL runlevel AUTOBOOT BOOT_IMAGE OSTYPE SHLVL _