Actually, only "source" the variable assignment we expect.

config/chroot_local-includes/usr/local/sbin/unsafe-browser

@@ -100,11 +100,12 @@ if [ -r "${NM_ENV_FILE}" ]; then
     # script. Note that while the regex used for deciding IP addresses
     # is far from perfect, it serves our purpose here.
     IP4_REGEX='[0-9]\{1,3\}\(\.[0-9]\{1,3\}\)\{3\}'
-    if grep -v "^IP4_NAMESERVERS=\"${IP4_REGEX}\"$" "${NM_ENV_FILE}"; then
+    NAMESERVERS_REGEX="^IP4_NAMESERVERS=\"${IP4_REGEX}\"$"
+    if grep -v "${NAMESERVERS_REGEX}" "${NM_ENV_FILE}"; then
         error "`gettext \"NetworkManager passed us garbage data when trying to deduce the clearnet DNS server.\"`"
     fi
     # Import the IP4_NAMESERVERS variable.
-    . "${NM_ENV_FILE}"
+    eval "$(grep "${NAMESERVERS_REGEX}" "${NM_ENV_FILE}")"
 fi
 # ... otherwise fail.
 # FIXME: Or would it make sense to fallback to Google's DNS or OpenDNS?