@@ -1,6 +1,22 @@

 # usage: source hacking/env-setup [-q]

 #    modifies environment for running Ansible from checkout

+# prepend a value to a potentially empty path variable

+# usage: prepend_path variable_name value

+prepend_path()

+{

+    variable_name="$1"

+    value="$2"

+

+    old_value=$( eval "echo \$$variable_name" )

+

+    if [ "x$old_value" != "x" ]; then

+        value="$value:"

+    fi

+

+    export "$variable_name=$value$old_value"

+}

+

 # Default values for shell variables we use

 PYTHONPATH=${PYTHONPATH-""}

 PATH=${PATH-""}

@@ -34,9 +50,9 @@ PREFIX_PYTHONPATH="$ANSIBLE_HOME/lib"

 PREFIX_PATH="$ANSIBLE_HOME/bin:$ANSIBLE_HOME/test/runner"

 PREFIX_MANPATH="$ANSIBLE_HOME/docs/man"

-expr "$PYTHONPATH" : "${PREFIX_PYTHONPATH}.*" > /dev/null || export PYTHONPATH="$PREFIX_PYTHONPATH:$PYTHONPATH"

-expr "$PATH" : "${PREFIX_PATH}.*" > /dev/null || export PATH="$PREFIX_PATH:$PATH"

-expr "$MANPATH" : "${PREFIX_MANPATH}.*" > /dev/null || export MANPATH="$PREFIX_MANPATH:$MANPATH"

+expr "$PYTHONPATH" : "${PREFIX_PYTHONPATH}.*" > /dev/null || prepend_path PYTHONPATH "$PREFIX_PYTHONPATH"

+expr "$PATH" : "${PREFIX_PATH}.*" > /dev/null || prepend_path PATH "$PREFIX_PATH"

+expr "$MANPATH" : "${PREFIX_MANPATH}.*" > /dev/null || prepend_path MANPATH "$PREFIX_MANPATH"

 #

 # Generate egg_info so that pkg_resources works