Fix sorting with custom comparator, and add unit tests to regress

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

@@ -645,7 +645,7 @@ public class LTable extends LValue {
 			vm.pushlvalue(m_vector[i]);
 			vm.pushlvalue(m_vector[j]);
 			vm.call(2, 1);
-			boolean result = vm.toboolean(1);
+			boolean result = vm.toboolean(-1);
 			vm.resettop();
 			return result;
 		} else {

src/test/java/org/luaj/vm/LuaJTest.java

@@ -148,6 +148,10 @@ public class LuaJTest extends TestCase {
             runTest( "strlib" );
         }
         
+        public void testSort() throws IOException, InterruptedException {
+            runTest( "sort" );
+        }
+
         public void testTable() throws IOException, InterruptedException {
                 runTest( "table" );
         }

src/test/res/sort.lua

@@ -0,0 +1,27 @@
+-- concat
+print( '-- sort tests' )
+local function tryall(cmp)
+	local function try(t)
+		print( table.concat(t,'-') )
+		if pcall( table.sort, t, cmp ) then
+			print( table.concat(t,'-') )
+		else
+			print( 'sort failed' )
+		end
+	end
+	try{ 2, 4, 6, 8, 1, 3, 5, 7 }
+	try{ 333, 222, 111 }
+	try{ "www", "xxx", "yyy", "aaa", "bbb", "ccc" }
+	try{ 21, 23, "25", 27, 22, "24", 26, 28 }
+end
+local function comparator(a,b)
+	return tonumber(a)<tonumber(b) 
+end
+tryall()
+tryall(comparator)
+
+
+
+
+
+