Revert 8d1c42296fefc4e79189b6c2d78a8a78fdd9576d

diff --git a/src/core.js b/src/core.js
index 39e68c4fcebdf70c1ecc17aa44f25fcb0818ea78..cae3a90e39f5c7ed8aff871fd0f91857512209a5 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -422,11 +422,8 @@ jQuery.extend({
        },
 
        isPlainObject: function( obj ) {
-               var key;
                // Not plain objects:
                // - Any object or value whose internal [[Class]] property is not "[object Object]"
-               //   ...Unless it was a constructor, whose prototype property was paved over by
-               //   by a plain object at its declaration. #13571
                // - DOM nodes
                // - window
                if ( jQuery.type( obj ) !== "object" || obj.nodeType || jQuery.isWindow( obj ) ) {
@@ -445,11 +442,9 @@ jQuery.extend({
                        return false;
                }
 
-               // Own properties are enumerated firstly, so to speed up,
-               // if last one is own, then all properties are own.
-               for ( key in obj ) {}
-
-               return key === undefined || core_hasOwn.call( obj, key );
+               // If the function hasn't returned already, we're confident that
+               // |obj| is a plain object, created by {} or constructed with new Object
+               return true;
        },
 
        isEmptyObject: function( obj ) {

diff --git a/test/unit/core.js b/test/unit/core.js
index 79367771118199e50dfaa0cf89465d8bfdc3884b..7c840993b6f33c5f2ef6a9a69bad70dee9535639 100644 (file)
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -296,9 +296,9 @@ test("type", function() {
 });
 
 asyncTest("isPlainObject", function() {
-       expect(16);
+       expect(15);
 
-       var pass, iframe, doc, c, extended,
+       var pass, iframe, doc,
                fn = function() {};
 
        // The use case that we want to match
@@ -360,45 +360,6 @@ asyncTest("isPlainObject", function() {
        } catch(e) {
                window.iframeDone( Object, "iframes not supported" );
        }
-
-       // #13571
-       function C() {}
-       C.prototype = {
-               x: 1
-       };
-       c = new C();
-
-       extended = jQuery.extend( true, {}, {
-               target: c
-       });
-
-       strictEqual(
-               extended.target, c,
-               "Instances, whose constructor defined its prototype by assigning a plain object, " +
-               "will lie about their true identity to preserve a broken user-code expectation"
-       );
-       //
-       // The test above is broken and tests a broken feature, to support a misinformed
-       // assumption, as documented here:
-       //
-       // http://bugs.jquery.com/ticket/13571#comment:4
-       //
-       // It will not pass if the object being assigned as the prototype
-       // has no properties:
-       //
-       // function C() {}
-       // C.prototype = {};
-       // c = new C();
-
-       // extended = jQuery.extend( true, {}, {
-       //      target: c
-       // });
-
-       // strictEqual( extended.target, c, "Undetectable, will fail every time" );
-       //
-       // The solution is to reset the constructor property of your plain object prototypes.
-       //
-       //
 });
 
 test("isFunction", function() {