diff --git a/bin/uglifyjs b/bin/uglifyjs
index a5a9fec0..26fd8efe 100755
--- a/bin/uglifyjs
+++ b/bin/uglifyjs
@@ -238,28 +238,15 @@ function run() {
             result.ast.figure_out_scope({});
         }
         print(JSON.stringify(result.ast, function(key, value) {
-            switch (key) {
+            if (value) switch (key) {
               case "thedef":
-                if (typeof value == "object" && typeof value.id == "number") {
-                    return value.id;
-                }
-                return;
+                return symdef(value);
               case "enclosed":
-                return value.map(function(sym){
-                    return sym.id;
-                });
+                return value.length ? value.map(symdef) : undefined;
               case "variables":
               case "functions":
               case "globals":
-                if (value && value.size()) {
-                    var ret = {};
-                    value.each(function(val, key) {
-                        // key/val inverted for readability.
-                        ret[val.id] = key;
-                    });
-                    return ret;
-                }
-                return;
+                return value.size() ? value.map(symdef) : undefined;
             }
             if (skip_key(key)) return;
             if (value instanceof UglifyJS.AST_Token) return;
@@ -419,6 +406,12 @@ function skip_key(key) {
     return skip_keys.indexOf(key) >= 0;
 }
 
+function symdef(def) {
+    var ret = (1e6 + def.id) + " " + def.name;
+    if (def.mangled_name) ret += " " + def.mangled_name;
+    return ret;
+}
+
 function format_object(obj) {
     var lines = [];
     var padding = "";
diff --git a/lib/compress.js b/lib/compress.js
index 773c0d60..f7e49424 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1829,6 +1829,7 @@ merge(Compressor.prototype, {
             do {
                 var node = exprs[0];
                 if (!(node instanceof AST_Assign)) break;
+                if (node.operator != "=") break;
                 if (!(node.left instanceof AST_PropAccess)) break;
                 var sym = node.left.expression;
                 if (!(sym instanceof AST_SymbolRef)) break;
@@ -1865,8 +1866,26 @@ merge(Compressor.prototype, {
                         statements[++j] = stat;
                         defs = stat;
                     }
+                } else if (stat instanceof AST_Exit) {
+                    var exprs = join_object_assignments(prev, stat.value);
+                    if (exprs) {
+                        CHANGED = true;
+                        if (exprs.length) {
+                            stat.value = make_sequence(stat.value, exprs);
+                        } else if (stat.value instanceof AST_Sequence) {
+                            stat.value = stat.value.tail_node().left;
+                        } else {
+                            stat.value = stat.value.left;
+                        }
+                    }
+                    statements[++j] = stat;
                 } else if (stat instanceof AST_For) {
-                    if (prev instanceof AST_Var && (!stat.init || stat.init.TYPE == prev.TYPE)) {
+                    var exprs = join_object_assignments(prev, stat.init);
+                    if (exprs) {
+                        CHANGED = true;
+                        stat.init = exprs.length ? make_sequence(stat.init, exprs) : null;
+                        statements[++j] = stat;
+                    } else if (prev instanceof AST_Var && (!stat.init || stat.init.TYPE == prev.TYPE)) {
                         if (stat.init) {
                             prev.definitions = prev.definitions.concat(stat.init.definitions);
                         }
diff --git a/lib/scope.js b/lib/scope.js
index dadc589e..be4ad02b 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -58,7 +58,7 @@ function SymbolDef(scope, orig, init) {
     this.id = SymbolDef.next_id++;
 };
 
-SymbolDef.next_id = 1e6;
+SymbolDef.next_id = 1;
 
 SymbolDef.prototype = {
     unmangleable: function(options) {
diff --git a/package.json b/package.json
index 231f2333..d040201d 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "homepage": "https://github.com/mishoo/UglifyJS2/tree/harmony",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.3.6",
+  "version": "3.3.7",
   "engines": {
     "node": ">=0.8.0"
   },
diff --git a/test/compress/properties.js b/test/compress/properties.js
index a17fe690..9144d9c7 100644
--- a/test/compress/properties.js
+++ b/test/compress/properties.js
@@ -1465,3 +1465,113 @@ join_object_assignments_3: {
     }
     expect_stdout: "PASS"
 }
+
+join_object_assignments_4: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = "foo";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: "foo"
+            };
+            return o.q;
+        }());
+    }
+    expect_stdout: "foo"
+}
+
+join_object_assignments_5: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = /foo/,
+            o.r = "bar";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: /foo/,
+                r: "bar"
+            };
+            return o.r;
+        }());
+    }
+    expect_stdout: "bar"
+}
+
+join_object_assignments_6: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            return o.q = "foo",
+            o.p += "",
+            console.log(o.q),
+            o.p;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            var o = {
+                p: 3,
+                q: "foo"
+            };
+            return o.p += "",
+            console.log(o.q),
+            o.p;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "3",
+    ]
+}
+
+join_object_assignments_7: {
+    options = {
+        join_vars: true,
+    }
+    input: {
+        console.log(function() {
+            var o = {
+                p: 3
+            };
+            for (o.q = "foo"; console.log(o.q););
+            return o.p;
+        }());
+    }
+    expect: {
+        console.log(function() {
+            for (var o = {
+                p: 3,
+                q: "foo"
+            }; console.log(o.q););
+            return o.p;
+        }());
+    }
+    expect_stdout: [
+        "foo",
+        "3",
+    ]
+}