docker-entrypoint.sh unconditionally creates ROUNDCUBEMAIL_TEMP_DIR

[rekup]

In the docker-entrypoint.sh script there are the following lines:

roundcubemail-docker/apache/docker-entrypoint.sh

Lines 218 to 220 in ce5fe1f

	if [ ! -z "${ROUNDCUBEMAIL_TEMP_DIR}" ]; then
	mkdir -p ${ROUNDCUBEMAIL_TEMP_DIR} && chown www-data ${ROUNDCUBEMAIL_TEMP_DIR}
	fi

By checking -z in the conditional, I assume the intention was to execute mkdir/chown only when ROUNDCUBEMAIL_TEMP_DIR is not empty. However, this variable can never be empty because of the following line:

roundcubemail-docker/apache/docker-entrypoint.sh

Line 119 in ce5fe1f

: "${ROUNDCUBEMAIL_TEMP_DIR:=/tmp/roundcube-temp}"

The := operator assigns the default value when the variable is either unset or empty. As a result, it is impossible to disable creation of the temporary directory by setting:

ROUNDCUBEMAIL_TEMP_DIR=""

because the variable is immediately replaced with /tmp/roundcube-temp.

One possible fix would be to use = instead of :=, which would preserve an explicitly empty value while still providing a default when the variable is unset.

Before opening a PR, I wanted to check whether there is a specific reason for the current implementation.