1 files changed, 28 insertions, 17 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 8936125d..144a5334 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -927,6 +927,7 @@ merge(Compressor.prototype, {
             return true;
         });
         def(AST_Lambda, function(tw, descend, compressor) {
+            this.inlined = false;
             push(tw);
             reset_variables(tw, compressor, this);
             descend();
@@ -1630,7 +1631,7 @@ merge(Compressor.prototype, {
                     var assign_used = false;
                     var can_replace = !args || !hit;
                     if (!can_replace) {
-                        for (var j = compressor.self().argnames.lastIndexOf(candidate.name) + 1; !abort && j < args.length; j++) {
+                        for (var j = scope.argnames.lastIndexOf(candidate.name) + 1; !abort && j < args.length; j++) {
                             args[j].transform(scanner);
                         }
                         can_replace = true;
@@ -1819,7 +1820,7 @@ merge(Compressor.prototype, {
 
             function extract_args() {
                 var iife, fn = compressor.self();
-                if (fn instanceof AST_Function
+                if (is_function(fn)
                     && !fn.name
                     && !fn.uses_arguments
                     && !fn.pinned()
@@ -1830,6 +1831,29 @@ merge(Compressor.prototype, {
                     })) {
                     var fn_strict = compressor.has_directive("use strict");
                     if (fn_strict && !member(fn_strict, fn.body)) fn_strict = false;
+                    var has_await = fn instanceof AST_AsyncFunction ? function(node) {
+                        return node instanceof AST_Symbol && node.name == "await";
+                    } : function(node) {
+                        return node instanceof AST_Await && !tw.find_parent(AST_Scope);
+                    };
+                    var tw = new TreeWalker(function(node) {
+                        if (!arg) return true;
+                        if (has_await(node)) {
+                            arg = null;
+                            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 (node instanceof AST_This && (fn_strict || !tw.find_parent(AST_Scope))) {
+                            arg = null;
+                            return true;
+                        }
+                    });
                     var len = fn.argnames.length;
                     args = iife.args.slice(len);
                     var names = Object.create(null);
@@ -1852,20 +1876,7 @@ merge(Compressor.prototype, {
                         } else if (arg instanceof AST_Lambda && arg.pinned()) {
                             arg = null;
                         } 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 (node instanceof AST_This && (fn_strict || !this.find_parent(AST_Scope))) {
-                                    arg = null;
-                                    return true;
-                                }
-                            }));
+                            arg.walk(tw);
                         }
                         if (arg) candidates.unshift([ make_node(AST_VarDef, sym, {
                             name: sym,
@@ -8982,7 +8993,7 @@ merge(Compressor.prototype, {
                         single_use = fixed.is_constant_expression(self.scope);
                         if (single_use == "f") {
                             var scope = self.scope;
-                            do if (scope instanceof AST_Defun || scope instanceof AST_Function) {
+                            do if (is_defun(scope) || is_function(scope)) {
                                 scope.inlined = true;
                             } while (scope = scope.parent_scope);
                         }