Fix build errors for j2me. #32

Check code:
```
print(pcall(load('string.gsub("test", "%S", "A%")')))
print(pcall(load('string.gsub("test", "%S", "%A")')))
```

examples/jse/SampleApplet.java

@@ -11,13 +11,13 @@ import org.luaj.vm2.lib.Bit32Lib;
 import org.luaj.vm2.lib.CoroutineLib;
 import org.luaj.vm2.lib.PackageLib;
 import org.luaj.vm2.lib.ResourceFinder;
-import org.luaj.vm2.lib.StringLib;
 import org.luaj.vm2.lib.TableLib;
 import org.luaj.vm2.lib.jse.CoerceJavaToLua;
 import org.luaj.vm2.lib.jse.JseBaseLib;
 import org.luaj.vm2.lib.jse.JseIoLib;
 import org.luaj.vm2.lib.jse.JseMathLib;
 import org.luaj.vm2.lib.jse.JseOsLib;
+import org.luaj.vm2.lib.jse.JseStringLib;
 import org.luaj.vm2.lib.jse.LuajavaLib;
 
 /**
@@ -76,7 +76,7 @@ public class SampleApplet extends Applet implements ResourceFinder {
 		globals.load(new PackageLib());
 		globals.load(new Bit32Lib());
 		globals.load(new TableLib());
-		globals.load(new StringLib());
+		globals.load(new JseStringLib());
 		globals.load(new CoroutineLib());
 		globals.load(new JseMathLib());
 		globals.load(new JseIoLib());

examples/jse/SampleSandboxed.java

@@ -1,7 +1,21 @@
-import org.luaj.vm2.*;
+import org.luaj.vm2.Globals;
+import org.luaj.vm2.LoadState;
+import org.luaj.vm2.LuaBoolean;
+import org.luaj.vm2.LuaString;
+import org.luaj.vm2.LuaTable;
+import org.luaj.vm2.LuaThread;
+import org.luaj.vm2.LuaValue;
+import org.luaj.vm2.Varargs;
 import org.luaj.vm2.compiler.LuaC;
-import org.luaj.vm2.lib.*;
-import org.luaj.vm2.lib.jse.*;
+import org.luaj.vm2.lib.Bit32Lib;
+import org.luaj.vm2.lib.DebugLib;
+import org.luaj.vm2.lib.PackageLib;
+import org.luaj.vm2.lib.TableLib;
+import org.luaj.vm2.lib.TwoArgFunction;
+import org.luaj.vm2.lib.ZeroArgFunction;
+import org.luaj.vm2.lib.jse.JseBaseLib;
+import org.luaj.vm2.lib.jse.JseMathLib;
+import org.luaj.vm2.lib.jse.JseStringLib;
 
 /** Simple program that illustrates basic sand-boxing of client scripts
  * in a server environment.
@@ -29,7 +43,7 @@ public class SampleSandboxed {
 		server_globals = new Globals();
 		server_globals.load(new JseBaseLib());
 		server_globals.load(new PackageLib());
-		server_globals.load(new StringLib());
+		server_globals.load(new JseStringLib());
 
 		// To load scripts, we occasionally need a math library in addition to compiler support.
 		// To limit scripts using the debug library, they must be closures, so we only install LuaC.
@@ -82,7 +96,7 @@ public class SampleSandboxed {
 		user_globals.load(new PackageLib());
 		user_globals.load(new Bit32Lib());
 		user_globals.load(new TableLib());
-		user_globals.load(new StringLib());
+		user_globals.load(new JseStringLib());
 		user_globals.load(new JseMathLib());
 
 		// This library is dangerous as it gives unfettered access to the

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

@@ -177,7 +177,14 @@ public class LuaDouble extends LuaNumber {
 	 * @see #dmod_d(double, double) 
 	 */
 	public static LuaValue dmod(double lhs, double rhs) {
-		return rhs!=0? valueOf( lhs-rhs*Math.floor(lhs/rhs) ): NAN;
+		if (rhs == 0 || lhs == Double.POSITIVE_INFINITY || lhs == Double.NEGATIVE_INFINITY) return NAN;
+		if (rhs == Double.POSITIVE_INFINITY) {
+			return lhs < 0 ? POSINF : valueOf(lhs);
+		}
+		if (rhs == Double.NEGATIVE_INFINITY) {
+			return lhs > 0 ? NEGINF : valueOf(lhs);
+		}
+		return valueOf( lhs-rhs*Math.floor(lhs/rhs) );
 	}
 
 	/** Take modulo for double numbers according to lua math, and return a double result.
@@ -188,7 +195,14 @@ public class LuaDouble extends LuaNumber {
 	 * @see #dmod(double, double)
 	 */
 	public static double dmod_d(double lhs, double rhs) {
-		return rhs!=0? lhs-rhs*Math.floor(lhs/rhs): Double.NaN;
+		if (rhs == 0 || lhs == Double.POSITIVE_INFINITY || lhs == Double.NEGATIVE_INFINITY) return Double.NaN;
+		if (rhs == Double.POSITIVE_INFINITY) {
+			return lhs < 0 ? Double.POSITIVE_INFINITY : lhs;
+		}
+		if (rhs == Double.NEGATIVE_INFINITY) {
+			return lhs > 0 ? Double.NEGATIVE_INFINITY : lhs;
+		}
+		return lhs-rhs*Math.floor(lhs/rhs);
 	}
 
 	// relational operators

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

@@ -391,23 +391,23 @@ public class LuaString extends LuaValue {
 	public short   toshort()       { return (short) toint(); }
 
 	public double optdouble(double defval) {
-		return checknumber().checkdouble();
+		return checkdouble();
 	}
 	
 	public int optint(int defval) {
-		return checknumber().checkint();
+		return checkint();
 	}
 	
 	public LuaInteger optinteger(LuaInteger defval) { 
-		return checknumber().checkinteger();
+		return checkinteger();
 	}
 	
 	public long optlong(long defval) {
-		return checknumber().checklong();
+		return checklong();
 	}
 	
 	public LuaNumber optnumber(LuaNumber defval) {
-		return checknumber().checknumber();
+		return checknumber();
 	}
 	
 	public LuaString optstring(LuaString defval) {

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

@@ -643,7 +643,7 @@ public class LuaValue extends Varargs {
 	 * @see #isnumber()
 	 * @see #TNUMBER
 	 */
-	public double      optdouble(double defval)            { argerror("double");    return 0;     }
+	public double      optdouble(double defval)            { argerror("number");    return 0;     }
 
 	/** Check that optional argument is a function and return as {@link LuaFunction}
 	 * <p>
@@ -855,7 +855,7 @@ public class LuaValue extends Varargs {
 	 * @see #optdouble(double)
 	 * @see #TNUMBER
 	 */
-	public double      checkdouble()           { argerror("double");    return 0; }
+	public double      checkdouble()           { argerror("number");    return 0; }
 	
 	/** Check that the value is a function , or throw {@link LuaError} if not 
 	 * <p>

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

@@ -299,7 +299,8 @@ public class BaseLib extends TwoArgFunction implements ResourceFinder {
 		}
 		public LuaValue call(LuaValue table, LuaValue index, LuaValue value) {
 			LuaTable t = table.checktable();
-			t.rawset(index.checknotnil(), value);
+			if (!index.isvalidkey()) argerror(2, "value");
+			t.rawset(index, value);
 			return t;
 		}
 	}

src/core/org/luaj/vm2/lib/Bit32Lib.java

@@ -71,7 +71,7 @@ public class Bit32Lib extends TwoArgFunction {
 			"arshift", "lrotate", "lshift", "rrotate", "rshift"
 		});
 		env.set("bit32", t);
-		env.get("package").get("loaded").set("bit32", t);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("bit32", t);
 		return t;
 	}
 

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

@@ -82,7 +82,7 @@ public class CoroutineLib extends TwoArgFunction {
 		coroutine.set("yield", new yield());
 		coroutine.set("wrap", new wrap());
 		env.set("coroutine", coroutine);
-		env.get("package").get("loaded").set("coroutine", coroutine);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("coroutine", coroutine);
 		return coroutine;
 	}
 

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

@@ -135,7 +135,7 @@ public class DebugLib extends TwoArgFunction {
 		debug.set("upvalueid", new upvalueid());
 		debug.set("upvaluejoin", new upvaluejoin());
 		env.set("debug", debug);
-		env.get("package").get("loaded").set("debug", debug);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("debug", debug);
 		return debug;
 	}
 

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

@@ -256,7 +256,7 @@ public class IoLib extends TwoArgFunction {
 		
 		// return the table
 		env.set("io", t);
-		env.get("package").get("loaded").set("io", t);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("io", t);
 		return t;
 	}
 

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

@@ -125,7 +125,7 @@ public class MathLib extends TwoArgFunction {
 		math.set("sqrt", new sqrt());
 		math.set("tan", new tan());
 		env.set("math", math);
-		env.get("package").get("loaded").set("math", math);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("math", math);
 		return math;
 	}
 	
@@ -163,10 +163,12 @@ public class MathLib extends TwoArgFunction {
 		}
 	}
 	
-	static final class fmod extends BinaryOp {
-		protected double call(double x, double y) {
-			double q = x/y;
-			return x - y * (q>=0? Math.floor(q): Math.ceil(q));
+	static final class fmod extends TwoArgFunction {
+		public LuaValue call(LuaValue xv, LuaValue yv) {
+			if (xv.islong() && yv.islong()) {
+				return valueOf(xv.tolong() % yv.tolong());
+			}
+			return valueOf(xv.checkdouble() % yv.checkdouble());
 		}
 	}
 	static final class ldexp extends BinaryOp {
@@ -194,27 +196,36 @@ public class MathLib extends TwoArgFunction {
 
 	static class max extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
-			double m = args.checkdouble(1);
-			for ( int i=2,n=args.narg(); i<=n; ++i )
-				m = Math.max(m,args.checkdouble(i));
-			return valueOf(m);
+			LuaValue m = args.checkvalue(1);
+			for ( int i=2,n=args.narg(); i<=n; ++i ) {
+				LuaValue v = args.checkvalue(i);
+				if (m.lt_b(v)) m = v;
+			}
+			return m;
 		}
 	}
 	
 	static class min extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
-			double m = args.checkdouble(1);
-			for ( int i=2,n=args.narg(); i<=n; ++i )
-				m = Math.min(m,args.checkdouble(i));
-			return valueOf(m);
+			LuaValue m = args.checkvalue(1);
+			for ( int i=2,n=args.narg(); i<=n; ++i ) {
+				LuaValue v = args.checkvalue(i);
+				if (v.lt_b(m)) m = v;
+			}
+			return m;
 		}
 	}
 	
 	static class modf extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
-			double x = args.checkdouble(1);
+			LuaValue n = args.arg1();
+			/* number is its own integer part, no fractional part */
+			if (n.islong()) return varargsOf(n, valueOf(0.0));
+			double x = n.checkdouble();
+			/* integer part (rounds toward zero) */
 			double intPart = ( x > 0 ) ? Math.floor( x ) : Math.ceil( x );
-			double fracPart = x - intPart;
+			/* fractional part (test needed for inf/-inf) */
+			double fracPart = x == intPart ? 0.0 : x - intPart;
 			return varargsOf( valueOf(intPart), valueOf(fracPart) );
 		}
 	}

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

@@ -132,7 +132,7 @@ public class OsLib extends TwoArgFunction {
 		for (int i = 0; i < NAMES.length; ++i)
 			os.set(NAMES[i], new OsLibFunc(i, NAMES[i]));
 		env.set("os", os);
-		env.get("package").get("loaded").set("os", os);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("os", os);
 		return os;
 	}
 

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

@@ -24,8 +24,8 @@ package org.luaj.vm2.lib;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
-import org.luaj.vm2.LuaClosure;
 import org.luaj.vm2.Buffer;
+import org.luaj.vm2.LuaClosure;
 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
 import org.luaj.vm2.LuaValue;
@@ -49,7 +49,7 @@ import org.luaj.vm2.compiler.DumpState;
  * Globals globals = new Globals();
  * globals.load(new JseBaseLib());
  * globals.load(new PackageLib());
- * globals.load(new StringLib());
+ * globals.load(new JseStringLib());
  * System.out.println( globals.get("string").get("upper").call( LuaValue.valueOf("abcde") ) );
  * } </pre>
  * <p>
@@ -99,7 +99,7 @@ public class StringLib extends TwoArgFunction {
 		string.set("upper", new upper());
 		
 		env.set("string", string);
-		env.get("package").get("loaded").set("string", string);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("string", string);
 		if (LuaString.s_metatable == null) {
 			LuaString.s_metatable = LuaValue.tableOf(new LuaValue[] { INDEX, string });
 		}
@@ -173,7 +173,7 @@ public class StringLib extends TwoArgFunction {
 	 * TODO: port dumping code as optional add-on
 	 */
 	static final class dump extends VarArgFunction {
-		public LuaValue invoke(Varargs args) {
+		public Varargs invoke(Varargs args) {
 			LuaValue f = args.checkfunction(1);
 			ByteArrayOutputStream baos = new ByteArrayOutputStream();
 			try {
@@ -230,7 +230,7 @@ public class StringLib extends TwoArgFunction {
 	 * This function does not accept string values containing embedded zeros,
 	 * except as arguments to the q option.
 	 */
-	static final class format extends VarArgFunction {
+	final class format extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
 			LuaString fmt = args.checkstring( 1 );
 			final int n = fmt.length();
@@ -261,7 +261,7 @@ public class StringLib extends TwoArgFunction {
 								break;
 							case 'i':
 							case 'd':
-								fdsc.format( result, args.checkint( arg ) );
+								fdsc.format( result, args.checklong( arg ) );
 								break;
 							case 'o':
 							case 'u':
@@ -330,7 +330,7 @@ public class StringLib extends TwoArgFunction {
 	
 	private static final String FLAGS = "-+ #0";
 	
-	static class FormatDesc {
+	class FormatDesc {
 		
 		private boolean leftAdjust;
 		private boolean zeroPad;
@@ -470,13 +470,7 @@ public class StringLib extends TwoArgFunction {
 		}
 		
 		public void format(Buffer buf, double x) {
-			String out;
-			try {
-				out = String.format(src, x);
-			} catch (Throwable e) {
-				out = String.valueOf( x );
-			}
-			buf.append( out );
+			buf.append( StringLib.this.format(src, x) );
 		}
 		
 		public void format(Buffer buf, LuaString s) {
@@ -486,13 +480,17 @@ public class StringLib extends TwoArgFunction {
 			buf.append(s);
 		}
 		
-		public static final void pad(Buffer buf, char c, int n) {
+		public final void pad(Buffer buf, char c, int n) {
 			byte b = (byte)c;
 			while ( n-- > 0 )
 				buf.append(b);
 		}
 	}
 	
+	protected String format(String src, double x) {
+		return String.valueOf(x);
+	}
+	
 	/**
 	 * string.gmatch (s, pattern)
 	 * 
@@ -877,8 +875,14 @@ public class StringLib extends TwoArgFunction {
 					lbuf.append( (byte) b );
 				} else {
 					++i; // skip ESC
-					b = (byte) news.luaByte( i );
+					b = (byte)(i < l ? news.luaByte( i ) : 0);
 					if ( !Character.isDigit( (char) b ) ) {
+						if (b != L_ESC) error( "invalid use of '" + (char)L_ESC +
+							"' in replacement string: after '" + (char)L_ESC +
+							"' must be '0'-'9' or '" + (char)L_ESC +
+							"', but found " + (i < l ? "symbol '" + (char)b + "' with code " + b +
+							" at pos " + (i + 1) :
+							"end of string"));
 						lbuf.append( b );
 					} else if ( b == '0' ) {
 						lbuf.append( s.substring( soff, e ) );

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

@@ -70,7 +70,7 @@ public class TableLib extends TwoArgFunction {
 		table.set("sort", new sort());
 		table.set("unpack", new unpack());
 		env.set("table", table);
-		env.get("package").get("loaded").set("table", table);
+		if (!env.get("package").isnil()) env.get("package").get("loaded").set("table", table);
 		return NIL;
 	}
 

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

@@ -98,7 +98,14 @@ public class JseMathLib extends org.luaj.vm2.lib.MathLib {
 	}
 	static final class cosh extends UnaryOp { protected double call(double d) { return Math.cosh(d); } }
 	static final class exp extends UnaryOp { protected double call(double d) { return Math.exp(d); } }
-	static final class log extends UnaryOp { protected double call(double d) { return Math.log(d); } }
+	static final class log extends TwoArgFunction {
+		public LuaValue call(LuaValue x, LuaValue base) {
+			double nat = Math.log(x.checkdouble());
+			double b = base.optdouble(Math.E);
+			if (b != Math.E) nat /= Math.log(b);
+			return valueOf(nat);
+		}
+	}
 	static final class pow extends BinaryOp { protected double call(double x, double y) { return Math.pow(x, y); } }
 	static final class sinh extends UnaryOp { protected double call(double d) { return Math.sinh(d); } }
 	static final class tanh extends UnaryOp { protected double call(double d) { return Math.tanh(d); } }

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

@@ -23,7 +23,6 @@ package org.luaj.vm2.lib.jse;
 
 import org.luaj.vm2.Globals;
 import org.luaj.vm2.LoadState;
-import org.luaj.vm2.LuaThread;
 import org.luaj.vm2.LuaValue;
 import org.luaj.vm2.Varargs;
 import org.luaj.vm2.compiler.LuaC;
@@ -98,7 +97,7 @@ public class JsePlatform {
 		globals.load(new PackageLib());
 		globals.load(new Bit32Lib());
 		globals.load(new TableLib());
-		globals.load(new StringLib());
+		globals.load(new JseStringLib());
 		globals.load(new CoroutineLib());
 		globals.load(new JseMathLib());
 		globals.load(new JseIoLib());

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

@@ -112,7 +112,7 @@ public class LuajavaLib extends VarArgFunction {
 				LuaTable t = new LuaTable();
 				bind( t, this.getClass(), NAMES, BINDCLASS );
 				env.set("luajava", t);
-				env.get("package").get("loaded").set("luajava", t);
+				if (!env.get("package").isnil()) env.get("package").get("loaded").set("luajava", t);
 				return t;
 			}
 			case BINDCLASS: {