Improved bash_completion handling

.bashrc

@@ -14,10 +14,16 @@ test -r ~/.shell-env && . ~/.shell-env
 test -f ~/.bash_private.gpg && \
   eval "$(gpg --decrypt ~/.bash_private.gpg 2>/dev/null)"
 
-# smart advanced completion, download from
-# http://bash-completion.alioth.debian.org/
-test -f ~/local/bin/bash_completion && \
-  . ~/local/bin/bash_completion
+# enable programmable completion features (you don't need to enable
+# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
+# sources /etc/bash.bashrc).
+test ! shopt -oq posix && {
+  test -f /usr/share/bash-completion/bash_completion && . /usr/share/bash-completion/bash_completion
+  test -f /etc/bash_completion && . /etc/bash_completion
+  # smart advanced completion, download from
+  # http://bash-completion.alioth.debian.org/
+  test -f ~/local/bin/bash_completion && . ~/local/bin/bash_completion
+}
 
 # http://unix.stackexchange.com/questions/72086/ctrl-s-hang-terminal-emulator
 # See "The TTY demystified" - http://linusakesson.net/programming/tty/index.php