Off-by-one error in CommandLineUtils.getSystemEnvVars(boolean) breaks envvars with single character names

There is an off-by-one error in org.codehaus.plexus.util.cli.CommandLineUtils.getSystemEnvVars(boolean) which manifests as environment variables having a single character name being ignored, and the previously occurring envvar being corrupted.

I noticed this one when it broke "mvn deploy", by corrupting my SSH_AUTH_SOCK environment variable.

The error is in the parsing of the output of the "env" program - the code does:

            int idx = line.indexOf( '=' );

            if ( idx > 1 )

The correct test is

            if ( idx > 0 )