Let os.getenv() return System.getenv() values first for JSE, then fall back to properties

src/core/org/luaj/vm2/lib/OsLib.java

@@ -404,8 +404,19 @@ public class OsLib extends TwoArgFunction {
 	}
 
 	/**
-	 * Returns the value of the process environment variable varname, 
-	 * or null if the variable is not defined. 
+	 * Returns the value of the process environment variable varname,
+	 * or the System property value for varname,
+	 * or null if the variable is not defined in either environment.
+	 * 
+	 * The default implementation, which is used by the JmePlatform,
+	 * only queryies System.getProperty(). 
+	 * 
+	 * The JsePlatform overrides this behavior and returns the
+	 * environment variable value using System.getenv() if it exists, 
+	 * or the System property value if it does not.
+	 * 
+	 * A SecurityException may be thrown if access is not allowed 
+	 * for 'varname'.
 	 * @param varname
 	 * @return String value, or null if not defined
 	 */

src/jse/org/luaj/vm2/lib/jse/JseOsLib.java

@@ -84,6 +84,11 @@ public class JseOsLib extends org.luaj.vm2.lib.OsLib {
 	public JseOsLib() {
 	}
 
+	protected String getenv(String varname) {
+		String s = System.getenv(varname);
+		return s != null? s : System.getProperty(varname);
+	}
+
 	protected Varargs execute(String command) {
 		int exitValue;
 		try {