fix corner cases with spread syntax (#4358)

1 files changed, 53 insertions, 33 deletions

diff --git a/lib/compress.js b/lib/compress.js
index fbf6036c..d4b911ee 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -3662,6 +3662,20 @@ merge(Compressor.prototype, {
         ],
     });
 
+    // Accomodate when compress option evaluate=false
+    // as well as the common constant expressions !0 and -1
+    (function(def) {
+        def(AST_Node, return_false);
+        def(AST_Constant, return_true);
+        def(AST_RegExp, return_false);
+        var unaryPrefix = makePredicate("! ~ - + void");
+        def(AST_UnaryPrefix, function() {
+            return unaryPrefix[this.operator] && this.expression instanceof AST_Constant;
+        });
+    })(function(node, func) {
+        node.DEFMETHOD("is_constant", func);
+    });
+
     // methods to evaluate a constant expression
     (function(def) {
         // If the node has been successfully reduced to a constant,
@@ -3686,18 +3700,6 @@ merge(Compressor.prototype, {
             if (typeof val == "function" || typeof val == "object") return this;
             return val;
         });
-        var unaryPrefix = makePredicate("! ~ - + void");
-        AST_Node.DEFMETHOD("is_constant", function() {
-            // Accomodate when compress option evaluate=false
-            // as well as the common constant expressions !0 and -1
-            if (this instanceof AST_Constant) {
-                return !(this instanceof AST_RegExp);
-            } else {
-                return this instanceof AST_UnaryPrefix
-                    && this.expression instanceof AST_Constant
-                    && unaryPrefix[this.operator];
-            }
-        });
         var scan_modified = new TreeWalker(function(node) {
             if (node instanceof AST_Assign) modified(node.left);
             if (node instanceof AST_Unary && unary_arithmetic[node.operator]) modified(node.expression);
@@ -6453,20 +6455,24 @@ merge(Compressor.prototype, {
                 }
             });
             var values = trim(exprs, compressor, first_in_statement, function(node, compressor, first_in_statement) {
-                var exp = node.expression;
-                if (exp instanceof AST_Object) return node;
-                if (exp instanceof AST_PropAccess) return node;
+                var exp = node.expression.tail_node();
                 if (exp instanceof AST_SymbolRef) {
                     exp = exp.fixed_value();
                     if (!exp) return node;
-                    if (exp instanceof AST_SymbolRef) return node;
-                    if (exp instanceof AST_PropAccess) return node;
-                    if (!(exp instanceof AST_Object)) return null;
-                    return all(exp.properties, function(prop) {
+                    exp = exp.tail_node();
+                }
+                if (exp instanceof AST_Array
+                    || exp.TYPE == "Binary" && !lazy_op[exp.operator]
+                    || exp instanceof AST_Constant
+                    || exp instanceof AST_Lambda
+                    || exp instanceof AST_Object && all(exp.properties, function(prop) {
                         return !(prop instanceof AST_ObjectGetter || prop instanceof AST_Spread);
-                    }) ? null : node;
+                    })
+                    || exp instanceof AST_This
+                    || exp instanceof AST_Unary) {
+                    return node.expression.drop_side_effect_free(compressor, first_in_statement);
                 }
-                return exp.drop_side_effect_free(compressor, first_in_statement);
+                return node;
             });
             if (!values) return null;
             if (values === exprs && !all(values, function(node) {
@@ -10043,26 +10049,36 @@ merge(Compressor.prototype, {
     OPT(AST_Object, function(self, compressor) {
         if (!compressor.option("objects")) return self;
         var changed = false;
-        var computed_int = false;
-        var has_computed = false;
+        var found = false;
+        var generated = false;
         var keep_duplicate = compressor.has_directive("use strict");
         var keys = new Dictionary();
         var values = [];
         self.properties.forEach(function(prop) {
             if (!(prop instanceof AST_Spread)) return process(prop);
+            found = true;
             var exp = prop.expression;
-            if (exp instanceof AST_Object && all(exp.properties, function(node) {
-                return node instanceof AST_ObjectKeyVal;
+            if (compressor.option("spread") && exp instanceof AST_Object && all(exp.properties, function(prop) {
+                return !(prop instanceof AST_ObjectGetter || prop instanceof AST_Spread);
             })) {
                 changed = true;
-                has_computed = true;
-                exp.properties.forEach(process);
+                exp.properties.forEach(function(prop) {
+                    if (prop instanceof AST_ObjectKeyVal) process(prop);
+                });
             } else {
+                generated = true;
                 flush();
                 values.push(prop);
             }
         });
         flush();
+        if (!changed) return self;
+        if (found && generated && values.length == 1) {
+            var value = values[0];
+            if (value instanceof AST_ObjectProperty && value.key instanceof AST_Number) {
+                value.key = "" + value.key.value;
+            }
+        }
         return changed ? make_node(AST_Object, self, {
             properties: values
         }) :  self;
@@ -10071,8 +10087,8 @@ merge(Compressor.prototype, {
             keys.each(function(props) {
                 if (props.length == 1) return values.push(props[0]);
                 changed = true;
-                var tail = keep_duplicate && props.pop();
-                values.push(make_node(AST_ObjectKeyVal, self, {
+                var tail = keep_duplicate && !generated && props.pop();
+                values.push(props.length == 1 ? props[0] : make_node(AST_ObjectKeyVal, self, {
                     key: props[0].key,
                     value: make_sequence(self, props.map(function(prop) {
                         return prop.value;
@@ -10086,9 +10102,13 @@ merge(Compressor.prototype, {
         function process(prop) {
             var key = prop.key;
             if (key instanceof AST_Node) {
-                has_computed = true;
+                found = true;
                 key = key.evaluate(compressor);
-                if (key !== prop.key) key = prop.key = "" + key;
+                if (key === prop.key) {
+                    generated = true;
+                } else {
+                    key = prop.key = "" + key;
+                }
             }
             if (prop instanceof AST_ObjectKeyVal && typeof key == "string") {
                 if (prop.value.has_side_effects(compressor)) flush();
@@ -10097,8 +10117,8 @@ merge(Compressor.prototype, {
                 flush();
                 values.push(prop);
             }
-            if (has_computed && !computed_int && typeof key == "string" && /^[0-9]+$/.test(key)) {
-                computed_int = true;
+            if (found && !generated && typeof key == "string" && /^[0-9]+$/.test(key)) {
+                generated = true;
                 prop.key = make_node(AST_Number, prop, {
                     value: +key
                 });