uglify.js in uglifier-1.2.2

- old
+ new

@@ -957,12 +957,15 @@
                 var init = null;
                 if (!is("punc", ";")) {
                         init = is("keyword", "var")
                                 ? (next(), var_(true))
                                 : expression(true, true);
-                        if (is("operator", "in"))
+                        if (is("operator", "in")) {
+                                if (init[0] == "var" && init[1].length > 1)
+                                        croak("Only one variable declaration allowed in for..in loop");
                                 return for_in(init);
+                        }
                 }
                 return regular_for(init);
         };
 
         function regular_for(init) {
@@ -2131,11 +2134,13 @@
                         var val = evaluate(expr), ast;
                         switch (typeof val) {
                             case "string": ast =  [ "string", val ]; break;
                             case "number": ast =  [ "num", val ]; break;
                             case "boolean": ast =  [ "name", String(val) ]; break;
-                            default: throw new Error("Can't handle constant of type: " + (typeof val));
+                            default:
+                                if (val === null) { ast = [ "atom", "null" ]; break; }
+                                throw new Error("Can't handle constant of type: " + (typeof val));
                         }
                         return yes.call(expr, ast, val);
                 } catch(ex) {
                         if (ex === $NOT_CONSTANT) {
                                 if (expr[0] == "binary"
@@ -2573,10 +2578,20 @@
                 }, function() {
                         return make_real_if(c, t, e);
                 });
         };
 
+        function abort_else(c, t, e) {
+                var ret = [ [ "if", negate(c), e ] ];
+                if (t[0] == "block") {
+                        if (t[1]) ret = ret.concat(t[1]);
+                } else {
+                        ret.push(t);
+                }
+                return walk([ "block", ret ]);
+        };
+
         function make_real_if(c, t, e) {
                 c = walk(c);
                 t = walk(t);
                 e = walk(e);
 
@@ -2606,13 +2621,14 @@
                 if (t[0] == "if" && empty(t[3]) && empty(e)) {
                         ret = best_of(ret, walk([ "if", [ "binary", "&&", c, t[1] ], t[2] ]));
                 }
                 else if (t[0] == "stat") {
                         if (e) {
-                                if (e[0] == "stat") {
+                                if (e[0] == "stat")
                                         ret = best_of(ret, [ "stat", make_conditional(c, t[1], e[1]) ]);
-                                }
+                                else if (aborts(e))
+                                        ret = abort_else(c, t, e);
                         }
                         else {
                                 ret = best_of(ret, [ "stat", make_conditional(c, t[1]) ]);
                         }
                 }
@@ -2628,16 +2644,10 @@
                                 ret.push(e);
                         }
                         ret = walk([ "block", ret ]);
                 }
                 else if (t && aborts(e)) {
-                        ret = [ [ "if", negate(c), e ] ];
-                        if (t[0] == "block") {
-                                if (t[1]) ret = ret.concat(t[1]);
-                        } else {
-                                ret.push(t);
-                        }
-                        ret = walk([ "block", ret ]);
+                        ret = abort_else(c, t, e);
                 }
                 return ret;
         };
 
         function _do_while(cond, body) {