fix corner case in call binding (#3128)

fixes #3127

1 files changed, 16 insertions, 10 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 8c565c21..d3c24529 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -919,15 +919,21 @@ merge(Compressor.prototype, {
                 type: typeof val
             }));
         }
-    };
+    }
+
+    function needs_unbinding(compressor, val) {
+        return val instanceof AST_PropAccess
+            || compressor.has_directive("use strict")
+                && is_undeclared_ref(val)
+                && val.name == "eval";
+    }
 
     // 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_this_binding(parent, orig, val) {
+    function maintain_this_binding(compressor, parent, orig, val) {
         if (parent instanceof AST_UnaryPrefix && parent.operator == "delete"
-            || parent.TYPE == "Call" && parent.expression === orig
-                && (val instanceof AST_PropAccess || val instanceof AST_SymbolRef && val.name == "eval")) {
+            || parent.TYPE == "Call" && parent.expression === orig && needs_unbinding(compressor, val)) {
             return make_sequence(orig, [ make_node(AST_Number, orig, { value: 0 }), val ]);
         }
         return val;
@@ -1098,7 +1104,7 @@ merge(Compressor.prototype, {
                         var def = candidate.name.definition();
                         if (def.references.length - def.replaced == 1 && !compressor.exposed(def)) {
                             def.replaced++;
-                            return maintain_this_binding(parent, node, candidate.value);
+                            return maintain_this_binding(compressor, parent, node, candidate.value);
                         }
                         return make_node(AST_Assign, candidate, {
                             operator: "=",
@@ -3346,7 +3352,7 @@ merge(Compressor.prototype, {
                         }
                         if (value) {
                             props.push(value);
-                            return maintain_this_binding(parent, node, make_sequence(node, props.map(function(prop) {
+                            return maintain_this_binding(compressor, parent, node, make_sequence(node, props.map(function(prop) {
                                 return prop.transform(tt);
                             })));
                         }
@@ -4477,7 +4483,7 @@ merge(Compressor.prototype, {
         var exp = this.expression;
         if (!(exp instanceof AST_Sequence)) return this;
         var tail = exp.tail_node();
-        if (tail instanceof AST_PropAccess && !(this instanceof AST_New)) return this;
+        if (needs_unbinding(compressor, tail) && !(this instanceof AST_New)) return this;
         var expressions = exp.expressions.slice(0, -1);
         var node = this.clone();
         node.expression = tail;
@@ -5028,7 +5034,7 @@ merge(Compressor.prototype, {
         var end = expressions.length - 1;
         trim_right_for_undefined();
         if (end == 0) {
-            self = maintain_this_binding(compressor.parent(), compressor.self(), expressions[0]);
+            self = maintain_this_binding(compressor, compressor.parent(), compressor.self(), expressions[0]);
             if (!(self instanceof AST_Sequence)) self = self.optimize(compressor);
             return self;
         }
@@ -5347,7 +5353,7 @@ merge(Compressor.prototype, {
                 var ll = fuzzy_eval(self.left);
                 if (!ll) {
                     compressor.warn("Condition left of && always false [{file}:{line},{col}]", self.start);
-                    return maintain_this_binding(compressor.parent(), compressor.self(), self.left).optimize(compressor);
+                    return maintain_this_binding(compressor, compressor.parent(), compressor.self(), self.left).optimize(compressor);
                 } else if (!(ll instanceof AST_Node)) {
                     compressor.warn("Condition left of && always true [{file}:{line},{col}]", self.start);
                     return make_sequence(self, [ self.left, self.right ]).optimize(compressor);
@@ -5386,7 +5392,7 @@ merge(Compressor.prototype, {
                     return make_sequence(self, [ self.left, self.right ]).optimize(compressor);
                 } else if (!(ll instanceof AST_Node)) {
                     compressor.warn("Condition left of || always true [{file}:{line},{col}]", self.start);
-                    return maintain_this_binding(compressor.parent(), compressor.self(), self.left).optimize(compressor);
+                    return maintain_this_binding(compressor, compressor.parent(), compressor.self(), self.left).optimize(compressor);
                 }
                 var rr = self.right.evaluate(compressor);
                 if (!rr) {