handle AST_Expansion in collapse_vars & inline

lib/compress.js

@@ -848,6 +848,21 @@ merge(Compressor.prototype, {
                 }
             }
 
+            function has_overlapping_symbol(fn, arg) {
+                var found = false;
+                arg.walk(new TreeWalker(function(node) {
+                    if (found) return true;
+                    if (node instanceof AST_SymbolRef && fn.variables.has(node.name)) {
+                        var s = node.definition().scope;
+                        if (s !== scope) while (s = s.parent_scope) {
+                            if (s === scope) return true;
+                        }
+                        found = true;
+                    }
+                }));
+                return found;
+            }
+
             function extract_args() {
                 var iife, fn = compressor.self();
                 if (is_func_expr(fn)
@@ -860,23 +875,27 @@ merge(Compressor.prototype, {
                         return !(arg instanceof AST_Expansion);
                     })) {
                     fn.argnames.forEach(function(sym, i) {
-                        if (!(sym instanceof AST_SymbolFunarg)) return;
-                        var arg = iife.args[i];
-                        if (!arg) arg = make_node(AST_Undefined, sym);
-                        else arg.walk(new TreeWalker(function(node) {
-                            if (!arg) return true;
-                            if (node instanceof AST_SymbolRef && fn.variables.has(node.name)) {
-                                var s = node.definition().scope;
-                                if (s !== scope) while (s = s.parent_scope) {
-                                    if (s === scope) return true;
-                                }
-                                arg = null;
+                        if (sym instanceof AST_Expansion) {
+                            var elements = iife.args.slice(i);
+                            if (all(elements, function(arg) {
+                                return !has_overlapping_symbol(fn, arg);
+                            })) {
+                                candidates.push(make_node(AST_VarDef, sym, {
+                                    name: sym.expression,
+                                    value: make_node(AST_Array, iife, {
+                                        elements: elements
+                                    })
+                                }));
                             }
-                        }));
-                        if (arg) candidates.push(make_node(AST_VarDef, sym, {
-                            name: sym,
-                            value: arg
-                        }));
+                        } else {
+                            var arg = iife.args[i];
+                            if (!arg) arg = make_node(AST_Undefined, sym);
+                            else if (has_overlapping_symbol(fn, arg)) arg = null;
+                            if (arg) candidates.push(make_node(AST_VarDef, sym, {
+                                name: sym,
+                                value: arg
+                            }));
+                        }
                     });
                 }
             }
@@ -945,11 +964,16 @@ merge(Compressor.prototype, {
 
             function remove_candidate(expr) {
                 if (expr.name instanceof AST_SymbolFunarg) {
-                    var index = compressor.self().argnames.indexOf(expr.name);
-                    var args = compressor.parent().args;
-                    if (args[index]) args[index] = make_node(AST_Number, args[index], {
-                        value: 0
-                    });
+                    var iife = compressor.parent(), argnames = compressor.self().argnames;
+                    var index = argnames.indexOf(expr.name);
+                    if (index < 0) {
+                        iife.args.length = Math.min(iife.args.length, argnames.length - 1);
+                    } else {
+                        var args = iife.args;
+                        if (args[index]) args[index] = make_node(AST_Number, args[index], {
+                            value: 0
+                        });
+                    }
                     return true;
                 }
                 var found = false;
@@ -3154,7 +3178,7 @@ merge(Compressor.prototype, {
             var pos = 0, last = 0;
             for (var i = 0, len = self.args.length; i < len; i++) {
                 if (fn.argnames[i] instanceof AST_Expansion) {
-                    if (fn.argnames[i].__unused) while (i < len) {
+                    if (fn.argnames[i].expression.__unused) while (i < len) {
                         var node = self.args[i++].drop_side_effect_free(compressor);
                         if (node) {
                             self.args[pos++] = node;
@@ -3403,6 +3427,7 @@ merge(Compressor.prototype, {
                 && !exp.uses_eval
                 && (exp.body instanceof AST_Node || exp.body.length == 1)
                 && all(exp.argnames, function(arg) {
+                    if (arg instanceof AST_Expansion) return arg.expression.__unused;
                     return arg.__unused;
                 })
                 && !self.has_pure_annotation(compressor)) {

test/compress/arrow.js

@@ -374,7 +374,7 @@ issue_2105_2: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
-/*
+
 issue_2136_2: {
     options = {
         arrows: true,
@@ -430,7 +430,7 @@ issue_2136_3: {
     expect_stdout: "2"
     node_version: ">=6"
 }
-*/
+
 call_args: {
     options = {
         arrows: true,

test/compress/drop-unused.js

@@ -1358,7 +1358,7 @@ issue_2136_1: {
     expect_stdout: "[]"
     node_version: ">=6"
 }
-/*
+
 issue_2136_2: {
     options = {
         collapse_vars: true,
@@ -1410,7 +1410,7 @@ issue_2136_3: {
     expect_stdout: "2"
     node_version: ">=6"
 }
-*/
+
 issue_2163: {
     options = {
         pure_funcs: [ "pure" ],