preserve ThisBinding for side_effects

lib/compress.js

@@ -179,9 +179,9 @@ merge(Compressor.prototype, {
     // we shouldn't compress (1,func)(something) to
     // func(something) because that changes the meaning of
     // the func (becomes lexical instead of global).
-    function maintain_call_binding(parent, orig, val) {
+    function maintain_this_binding(parent, orig, val) {
         if (parent instanceof AST_Call && parent.expression === orig) {
-            if (val instanceof AST_PropAccess || (val instanceof AST_Symbol && val.name === "eval")) {
+            if (val instanceof AST_PropAccess || val instanceof AST_SymbolRef && val.name === "eval") {
                 return make_node(AST_Seq, orig, {
                     car: make_node(AST_Number, orig, {
                         value: 0
@@ -383,7 +383,7 @@ merge(Compressor.prototype, {
                 if (is_lvalue(node, parent)) return node;
 
                 // Remove var definition and return its value to the TreeTransformer to replace.
-                var value = maintain_call_binding(parent, node, var_decl.value);
+                var value = maintain_this_binding(parent, node, var_decl.value);
                 var_decl.value = null;
 
                 var_defs.splice(var_defs_index, 1);
@@ -2125,7 +2125,7 @@ merge(Compressor.prototype, {
         if (!compressor.option("side_effects"))
             return self;
         if (!self.car.has_side_effects(compressor)) {
-            return maintain_call_binding(compressor.parent(), self, self.cdr);
+            return maintain_this_binding(compressor.parent(), self, self.cdr);
         }
         if (compressor.option("cascade")) {
             if (self.car instanceof AST_Assign
@@ -2315,10 +2315,10 @@ merge(Compressor.prototype, {
                 if (ll.length > 1) {
                     if (ll[1]) {
                         compressor.warn("Condition left of && always true [{file}:{line},{col}]", self.start);
-                        return maintain_call_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
+                        return maintain_this_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
                     } else {
                         compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
-                        return maintain_call_binding(compressor.parent(), self, ll[0]);
+                        return maintain_this_binding(compressor.parent(), self, ll[0]);
                     }
                 }
             }
@@ -2327,10 +2327,10 @@ merge(Compressor.prototype, {
                 if (ll.length > 1) {
                     if (ll[1]) {
                         compressor.warn("Condition left of || always true [{file}:{line},{col}]", self.start);
-                        return maintain_call_binding(compressor.parent(), self, ll[0]);
+                        return maintain_this_binding(compressor.parent(), self, ll[0]);
                     } else {
                         compressor.warn("Condition left of || always false [{file}:{line},{col}]", self.start);
-                        return maintain_call_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
+                        return maintain_this_binding(compressor.parent(), self, self.right.evaluate(compressor)[0]);
                     }
                 }
             }
@@ -2555,10 +2555,10 @@ merge(Compressor.prototype, {
         if (cond.length > 1) {
             if (cond[1]) {
                 compressor.warn("Condition always true [{file}:{line},{col}]", self.start);
-                return maintain_call_binding(compressor.parent(), self, self.consequent);
+                return maintain_this_binding(compressor.parent(), self, self.consequent);
             } else {
                 compressor.warn("Condition always false [{file}:{line},{col}]", self.start);
-                return maintain_call_binding(compressor.parent(), self, self.alternative);
+                return maintain_this_binding(compressor.parent(), self, self.alternative);
             }
         }
         var negated = cond[0].negate(compressor);

test/compress/issue-782.js

@@ -1,10 +1,12 @@
 remove_redundant_sequence_items: {
     options = { side_effects: true };
     input: {
+        (0, 1, eval)();
         (0, 1, logThis)();
         (0, 1, _decorators.logThis)();
     }
     expect: {
+        (0, eval)();
         logThis();
         (0, _decorators.logThis)();
     }
@@ -13,10 +15,12 @@ remove_redundant_sequence_items: {
 dont_remove_this_binding_sequence: {
     options = { side_effects: true };
     input: {
+        (0, eval)();
         (0, logThis)();
         (0, _decorators.logThis)();
     }
     expect: {
+        (0, eval)();
         logThis();
         (0, _decorators.logThis)();
     }

test/compress/issue-973.js

@@ -18,6 +18,11 @@ this_binding_conditionals: {
         (0 || a[b])();
         (0 || 1 && a[b])();
         (1 ? a[b] : 0)();
+
+        (1 && eval)();
+        (0 || eval)();
+        (0 || 1 && eval)();
+        (1 ? eval : 0)();
     }
     expect: {
         a();
@@ -34,6 +39,11 @@ this_binding_conditionals: {
         (0, a[b])();
         (0, a[b])();
         (0, a[b])();
+
+        (0, eval)();
+        (0, eval)();
+        (0, eval)();
+        (0, eval)();
     }
 }
 
@@ -44,26 +54,43 @@ this_binding_collapse_vars: {
     input: {
         var c = a; c();
         var d = a.b; d();
+        var e = eval; e();
     }
     expect: {
         a();
         (0, a.b)();
+        (0, eval)();
     }
 }
 
-eval_direct_calls: {
+this_binding_side_effects: {
     options = {
-        side_effects: true,
+        side_effects : true
-        collapse_vars: true
+    };
-    }
     input: {
-        (0, eval)('');
+        (function (foo) {
-
+            (0, foo)();
-        var fn = eval;
+            (0, foo.bar)();
-        fn('');
+            (0, eval)('console.log(foo);');
+        }());
+        (function (foo) {
+            var eval = console;
+            (0, foo)();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
     }
     expect: {
-        (0, eval)('');
+        (function (foo) {
-        (0, eval)('');
+            foo();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
+        (function (foo) {
+            var eval = console;
+            foo();
+            (0, foo.bar)();
+            (0, eval)('console.log(foo);');
+        }());
     }
 }