Fix compatibility vararg support when 'arg' variable is used.

src/core/org/luaj/compiler/LuaC.java

@@ -58,11 +58,6 @@ public class LuaC extends Lua implements LuaCompiler {
 	static final int LUAI_MAXVARS = 200;
 	static final int NO_REG		 = MAXARG_A;
 	
-	/* masks for new-style vararg */
-	static final int     VARARG_HASARG		= 1;
-	static final int     VARARG_ISVARARG	= 2;
-	static final int     VARARG_NEEDSARG	= 4;
-
 
 	/* OpMode - basic instruction format */
 	static final int 

src/core/org/luaj/vm/Lua.java

@@ -33,6 +33,10 @@ public class Lua {
 	/** use return values from previous op */
 	public static final int LUA_MULTRET = -1;
 
+	/** masks for new-style vararg */
+	public static final int     VARARG_HASARG		= 1;
+	public static final int     VARARG_ISVARARG	= 2;
+	public static final int     VARARG_NEEDSARG	= 4;
 	
 	// from lopcodes.h
 

src/core/org/luaj/vm/LuaState.java

@@ -171,12 +171,22 @@ public class LuaState extends Lua {
             int nfix = Math.min(narg, npar);
             int nvar = Math.max(0, narg-nfix);
             
+            
             // must copy args into position, add number parameter
             stack[top] = LInteger.valueOf(nvar);
             System.arraycopy(stack, base+1, stack, top+1, nfix);
             base = top + 1;
             top = base + nfix;
             luaV_adjusttop( base + npar );
+            
+            // add 'arg' compatibility variable
+            if ( (c.p.is_vararg & VARARG_NEEDSARG) != 0 ) {
+            	LTable arg = new LTable();
+            	for ( int i=1,j=base-nvar-1; i<=nvar; i++, j++ )
+            		arg.put(i, stack[j]);
+            	arg.put("n", nvar);
+            	pushlvalue( arg );
+            }
         }
         final int newcc = cc + 1;
         if ( newcc >= calls.length ) {

src/test/res/varargs.lua

@@ -5,18 +5,16 @@ function p(a,...)
 	print("...,a",...,a)
 	print("a,...",a,...)
 end
---[[ -- these have semantics that depend on compatibity flags
 function q(a,...)
-	print("a,arg[1],arg[2],arg[3]",a,arg[1],arg[2],arg[3])
+	print("a,arg[1],arg[2],arg[3]",a,arg.n,arg[1],arg[2],arg[3])
 end
 function r(a,...)
-	print("a,arg[1],arg[2],arg[3]",a,arg[1],arg[2],arg[3])
+	print("a,arg",a,arg)
 	print("a",a)
 	print("...",...)
 	print("...,a",...,a)
 	print("a,...",a,...)
 end
---]]
 function s(a)
 	local arg = { '1', '2', '3' }	
 	print("a,arg[1],arg[2],arg[3]",a,arg[1],arg[2],arg[3])
@@ -43,7 +41,7 @@ function tryall(f,name)
 	print( ' ->', pcall( f, "q", "r", "s" ) )
 end
 tryall(p,'p')
--- tryall(q,'q')
--- tryall(r,'r')
+tryall(q,'q')
+tryall(r,'r')
 tryall(s,'s')
 tryall(t,'t')