distinguish between binding/property assignments for `export default foo` special case

src/Statement.js

@@ -179,7 +179,7 @@ export default class Statement {
 			// special case = `export default foo; foo += 1;` - we'll
 			// need to assign a new variable so that the exported
 			// value is not updated by the second statement
-			if ( this.module.exports.default && this.module.exports.default.identifier === node.name ) {
+			if ( this.module.exports.default && depth === 0 && this.module.exports.default.identifier === node.name ) {
 				// but only if this is a) inside a function body or
 				// b) after the export declaration
 				if ( !!scope.parent || node.start > this.module.exports.default.statement.node.start ) {

test/form/unmodified-default-exports/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'does not treat property assignment as rebinding for sake of unbound default exports',
+	// solo: true
+};

test/form/unmodified-default-exports/_expected/amd.js

@@ -0,0 +1,15 @@
+define(function () { 'use strict';
+
+	var Foo = function () {
+		this.isFoo = true;
+	};
+
+	Foo.prototype = {
+		answer: function () {
+			return 42;
+		}
+	};
+
+	var foo = new Foo();
+
+});

test/form/unmodified-default-exports/_expected/cjs.js

@@ -0,0 +1,13 @@
+'use strict';
+
+var Foo = function () {
+	this.isFoo = true;
+};
+
+Foo.prototype = {
+	answer: function () {
+		return 42;
+	}
+};
+
+var foo = new Foo();

test/form/unmodified-default-exports/_expected/es6.js

@@ -0,0 +1,11 @@
+var Foo = function () {
+	this.isFoo = true;
+};
+
+Foo.prototype = {
+	answer: function () {
+		return 42;
+	}
+};
+
+var foo = new Foo();

test/form/unmodified-default-exports/_expected/iife.js

@@ -0,0 +1,15 @@
+(function () { 'use strict';
+
+	var Foo = function () {
+		this.isFoo = true;
+	};
+
+	Foo.prototype = {
+		answer: function () {
+			return 42;
+		}
+	};
+
+	var foo = new Foo();
+
+})();

test/form/unmodified-default-exports/_expected/umd.js

@@ -0,0 +1,19 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	factory();
+}(this, function () { 'use strict';
+
+	var Foo = function () {
+		this.isFoo = true;
+	};
+
+	Foo.prototype = {
+		answer: function () {
+			return 42;
+		}
+	};
+
+	var foo = new Foo();
+
+}));

test/form/unmodified-default-exports/foo.js

@@ -0,0 +1,11 @@
+var Foo = function () {
+	this.isFoo = true;
+};
+
+export default Foo;
+
+Foo.prototype = {
+	answer: function () {
+		return 42;
+	}
+};

test/form/unmodified-default-exports/main.js

@@ -0,0 +1,3 @@
+import Foo from './foo';
+
+var foo = new Foo();