fix reduce_vars on nested invocations (#3118)

lib/compress.js

@@ -340,10 +340,10 @@ merge(Compressor.prototype, {
         }
     }
 
-    (function(def){
+    (function(def) {
         def(AST_Node, noop);
 
-        function reset_def(compressor, def) {
+        function reset_def(tw, compressor, def) {
             def.assignments = 0;
             def.chained = false;
             def.direct_access = false;
@@ -355,15 +355,25 @@ merge(Compressor.prototype, {
             } else {
                 def.fixed = false;
             }
+            if (def.init instanceof AST_Defun && !all(def.references, same_defun_scope)) {
+                tw.defun_ids[def.id] = undefined;
+            }
             def.recursive_refs = 0;
             def.references = [];
             def.should_replace = undefined;
             def.single_use = undefined;
+
+            function same_defun_scope(ref) {
+                var scope = ref.scope;
+                do {
+                    if (def.scope === scope) return true;
+                } while (scope instanceof AST_Function && (scope = scope.parent_scope));
+            }
         }
 
         function reset_variables(tw, compressor, scope) {
             scope.variables.each(function(def) {
-                reset_def(compressor, def);
+                reset_def(tw, compressor, def);
                 if (def.fixed === null) {
                     def.safe_ids = tw.safe_ids;
                     mark(tw, def, true);
@@ -374,22 +384,14 @@ merge(Compressor.prototype, {
             });
         }
 
-        function same_defun_scope(def, ref) {
+        function walk_defun(tw, def) {
-            var scope = ref.scope;
-            do {
-                if (def.scope === scope) return true;
-            } while (scope instanceof AST_Function && (scope = scope.parent_scope));
-        }
-
-        function walk_defun(tw, ref) {
-            var def = ref.definition();
-            if (tw.in_loop || !same_defun_scope(def, ref)) {
-                if (tw.defun_ids[def.id] !== false) tw.defun_ids[def.id] = undefined;
-                return;
-            }
             if (def.id in tw.defun_ids) return;
-            tw.defun_ids[def.id] = true;
+            if (!tw.in_loop) {
-            def.fixed.walk(tw);
+                tw.defun_ids[def.id] = true;
+                def.fixed.walk(tw);
+            } else if (tw.defun_ids[def.id] !== false) {
+                tw.defun_ids[def.id] = undefined;
+            }
         }
 
         function walk_defuns(tw, scope) {
@@ -534,16 +536,10 @@ merge(Compressor.prototype, {
             return true;
         });
         def(AST_Call, function(tw, descend) {
-            var exp = this.expression;
-            if (!(exp instanceof AST_SymbolRef)) return;
-            var def = exp.definition();
-            if (!(def.fixed instanceof AST_Defun)) return;
-            if (def.id in tw.defun_ids) return;
-            tw.defun_ids[def.id] = 0;
             descend();
-            if (tw.defun_ids[def.id] === 0) {
+            var exp = this.expression;
-                delete tw.defun_ids[def.id];
+            if (exp instanceof AST_SymbolRef && exp.fixed_value() instanceof AST_Defun) {
-                walk_defun(tw, exp);
+                walk_defun(tw, exp.definition());
             }
             return true;
         });
@@ -708,11 +704,15 @@ merge(Compressor.prototype, {
                 }
             }
             mark_escaped(tw, d, this.scope, this, value, 0, 1);
-            if (d.fixed instanceof AST_Defun) walk_defun(tw, this);
+            var parent;
+            if (d.fixed instanceof AST_Defun
+                && !((parent = tw.parent()) instanceof AST_Call && parent.expression === this)) {
+                walk_defun(tw, d);
+            }
         });
         def(AST_Toplevel, function(tw, descend, compressor) {
             this.globals.each(function(def) {
-                reset_def(compressor, def);
+                reset_def(tw, compressor, def);
             });
             push(tw);
             reset_variables(tw, compressor, this);

test/compress/reduce_vars.js

@@ -5939,3 +5939,62 @@ issue_3113_3: {
     }
     expect_stdout: "1"
 }
+
+issue_3113_4: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0, b = 0;
+        function f() {
+            b += a;
+        }
+        f(f(), ++a);
+        console.log(a, b);
+    }
+    expect: {
+        var a = 0, b = 0;
+        function f() {
+            b += a;
+        }
+        f(f(), ++a);
+        console.log(a, b);
+    }
+    expect_stdout: "1 1"
+}
+
+issue_3113_5: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {
+            console.log(a);
+        }
+        function g() {
+            f();
+        }
+        while (g());
+        var a = 1;
+        f();
+    }
+    expect: {
+        function f() {
+            console.log(a);
+        }
+        function g() {
+            f();
+        }
+        while (g());
+        var a = 1;
+        f();
+    }
+    expect_stdout: [
+        "undefined",
+        "1",
+    ]
+}