elasticsearch.in.sh unintentionally adds CWD to classpath

[rmuir]

it does this like so:

ES_CLASSPATH="$ES_CLASSPATH:..."

When ES_CLASSPATH is empty we get a classpath like this:

:/wherever.jar:/whatever.jar

The empty path element gets interpreted as CWD.

I did fgrep -r ES_CLASSPATH and saw lots of logic in various packaging scripts, etc. We need to review how these scripts set the classpath and make sure they do not do this.

[rmuir]

Easy to reproduce, cd /, then run /path/to/bin/elasticsearch