fix `reduce_vars` on `AST_Defun` (#2708)

2 files changed, 18 insertions, 24 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 06873df8..1e096ade 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -316,7 +316,7 @@ merge(Compressor.prototype, {
             if (def.scope.uses_eval || def.scope.uses_with) {
                 def.fixed = false;
             } else if (!compressor.exposed(def)) {
-                def.fixed = undefined;
+                def.fixed = def.init;
             } else {
                 def.fixed = false;
             }
@@ -329,10 +329,12 @@ merge(Compressor.prototype, {
         function reset_variables(tw, compressor, node) {
             node.variables.each(function(def) {
                 reset_def(compressor, def);
-                if (def.fixed === undefined && def.orig[0].TYPE == "SymbolVar") {
-                    def.fixed = null;
+                if (def.fixed === null) {
                     def.safe_ids = tw.safe_ids;
                     mark(tw, def, true);
+                } else if (def.fixed) {
+                    tw.loop_ids[def.id] = tw.in_loop;
+                    mark(tw, def, true);
                 }
             });
         }
@@ -504,15 +506,6 @@ merge(Compressor.prototype, {
         });
         def(AST_Defun, function(tw, descend, compressor) {
             this.inlined = false;
-            var d = this.name.definition();
-            if (compressor.exposed(d) || safe_to_read(tw, d)) {
-                d.fixed = false;
-            } else {
-                d.fixed = this;
-                d.single_use = ref_once(tw, compressor, d);
-                tw.loop_ids[d.id] = tw.in_loop;
-                mark(tw, d, true);
-            }
             var save_ids = tw.safe_ids;
             tw.safe_ids = Object.create(null);
             reset_variables(tw, compressor, this);
diff --git a/lib/scope.js b/lib/scope.js
index bceec289..79b2475d 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -43,9 +43,10 @@
 
 "use strict";
 
-function SymbolDef(scope, orig) {
+function SymbolDef(scope, orig, init) {
     this.name = orig.name;
     this.orig = [ orig ];
+    this.init = init;
     this.eliminated = 0;
     this.scope = scope;
     this.references = [];
@@ -158,10 +159,10 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             // scope when we encounter the AST_Defun node (which is
             // instanceof AST_Scope) but we get to the symbol a bit
             // later.
-            (node.scope = defun.parent_scope).def_function(node);
+            (node.scope = defun.parent_scope).def_function(node, defun);
         }
         else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node);
+            defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
             if (defun !== scope) {
                 node.mark_enclosed(options);
                 var def = scope.find_variable(node);
@@ -306,21 +307,21 @@ AST_Scope.DEFMETHOD("find_variable", function(name){
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol){
-    var def = this.def_variable(symbol);
+AST_Scope.DEFMETHOD("def_function", function(symbol, init){
+    var def = this.def_variable(symbol, init);
+    if (!def.init) def.init = init;
     this.functions.set(symbol.name, def);
     return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol){
-    var def;
-    if (!this.variables.has(symbol.name)) {
-        def = new SymbolDef(this, symbol);
+AST_Scope.DEFMETHOD("def_variable", function(symbol, init){
+    var def = this.variables.get(symbol.name);
+    if (def) {
+        def.orig.push(symbol);
+    } else {
+        def = new SymbolDef(this, symbol, init);
         this.variables.set(symbol.name, def);
         def.global = !this.parent_scope;
-    } else {
-        def = this.variables.get(symbol.name);
-        def.orig.push(symbol);
     }
     return symbol.thedef = def;
 });