Improve compatibility with vm1 and C-based lua.

src/core/org/luaj/vm2/LuaValue.java

@@ -107,7 +107,7 @@ public class LuaValue extends Varargs {
 	public Object  touserdata()          { return null; }
 	public Object  touserdata(Class c)   { return null; }
 
-	// object tojstring() maps to tojstring() 
+	// Object.toString() maps to tojstring() 
 	public String toString() { return tojstring(); }
 	
 	// type coercion to lua values
@@ -519,9 +519,6 @@ public class LuaValue extends Varargs {
 		public LuaValue arg1() { 
 			return v1; 
 		}
-		public String tojstring() {
-			return "{"+v1+","+v2+"}";
-		}
 	}
 
 

src/core/org/luaj/vm2/Varargs.java

@@ -143,6 +143,9 @@ public abstract class Varargs {
 		sb.append( ")" );
 		return sb.tojstring();
 	}
+	
+	// Object.toString() maps to tojstring() 
+	public String toString() { return tojstring(); }
 
 	public Varargs subargs(final int start) {
 		int end = narg();

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

@@ -22,9 +22,12 @@
 package org.luaj.vm2.lib;
 
 import org.luaj.vm2.Lua;
+import org.luaj.vm2.LuaBoolean;
 import org.luaj.vm2.LuaClosure;
 import org.luaj.vm2.LuaError;
 import org.luaj.vm2.LuaFunction;
+import org.luaj.vm2.LuaNil;
+import org.luaj.vm2.LuaNumber;
 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
 import org.luaj.vm2.LuaThread;
@@ -534,10 +537,15 @@ public class DebugLib extends OneArgFunction {
 	private static Varargs _setmetatable(Varargs args) {
 		LuaValue object = args.arg(1);
 		try {
-			if ( ! args.isnoneornil(2) )
-				object.setmetatable(args.checktable(2));
-			else
-				object.setmetatable(null);
+			LuaValue mt = args.opttable(2, null);
+			switch ( object.type() ) {
+				case TNIL:      LuaNil.s_metatable      = mt; break;
+				case TNUMBER:   LuaNumber.s_metatable   = mt; break;
+				case TBOOLEAN:  LuaBoolean.s_metatable  = mt; break;
+				case TSTRING:   LuaString.s_metatable   = mt; break;
+				case TFUNCTION: LuaFunction.s_metatable = mt; break;
+				default: object.setmetatable( mt );
+			}
 			return LuaValue.TRUE;
 		} catch ( LuaError e ) {
 			return varargsOf(FALSE, valueOf(e.toString()));

src/jse/lua.java

@@ -126,7 +126,7 @@ public class lua {
 					break;
 				} else if ( "-".equals( args[i] ) ) {
 					setGlobalArg( _G, args, i );
-					processScript( System.in, "stdin" );
+					processScript( System.in, "=stdin" );
 					break;
 				} else {
 					switch ( args[i].charAt(1) ) {
@@ -202,7 +202,7 @@ public class lua {
 			String line = reader.readLine();
 			if ( line == null )
 				return;
-			processScript( new ByteArrayInputStream(line.getBytes()), "stdin" );
+			processScript( new ByteArrayInputStream(line.getBytes()), "=stdin" );
 		}
 	}
 }

src/jse/luac.java

@@ -134,7 +134,7 @@ public class luac {
 						String chunkname = args[i].substring(0,args[i].length()-4);
 						processScript( new FileInputStream(args[i]), chunkname, fos );
 					} else if ( args[i].length() <= 1 ) {
-						processScript( System.in, "stdin", fos );
+						processScript( System.in, "=stdin", fos );
 					} else {
 						switch ( args[i].charAt(1) ) {
 						case 'o':