Correct non-null|undefined evaluation of data property values. Fixes #9794

src/data.js

@@ -33,7 +33,9 @@ jQuery.extend({
 			return;
 		}
 
-		var internalKey = jQuery.expando, getByName = typeof name === "string", thisCache,
+		var thisCache, ret,
+			internalKey = jQuery.expando,
+			getByName = typeof name === "string",
 
 			// We have to handle DOM nodes and JS objects differently because IE6-7
 			// can't GC object references properly across the DOM-JS boundary
@@ -108,10 +110,24 @@ jQuery.extend({
 			return thisCache[ internalKey ] && thisCache[ internalKey ].events;
 		}
 
-		return getByName ? 
 		// Check for both converted-to-camel and non-converted data property names
-			thisCache[ jQuery.camelCase( name ) ] || thisCache[ name ] :
-			thisCache;
+		// If a data property was specified
+		if ( getByName ) {
+
+			// First try to find the camelCased property
+			ret = thisCache[ jQuery.camelCase( name ) ];
+
+			// Test for null|undefined property data was found
+			if ( ret == null ) {
+
+				// Try to find as-is property data
+				ret = thisCache[ name ];
+			}
+		} else {
+			ret = thisCache;
+		}
+
+		return ret;
 	},
 
 	removeData: function( elem, name, pvt /* Internal Use Only */ ) {

test/unit/data.js

@@ -525,3 +525,29 @@ test("jQuery.data should not miss data with preset hyphenated property names", f
 		equal( div.data(k), k, "data with property '"+k+"' was correctly found");
 	});
 });
+
+test("jQuery.data supports interoperable hyphenated/camelCase get/set of properties with arbitrary non-null|NaN|undefined values", function() {
+
+	var div = jQuery("<div/>", { id: "hyphened" }).appendTo("#qunit-fixture"),
+		datas = {
+			"non-empty": "a string",
+			"empty-string": "",
+			"one-value": 1,
+			"zero-value": 0,
+			"an-array": [],
+			"an-object": {},
+			"bool-true": true,
+			"bool-false": false,
+			"some-json": '{ "foo": "bar" }'
+		};
+
+	expect( 18 );
+
+	jQuery.each( datas, function( key, val ) {
+		div.data( key, val );
+
+		deepEqual( div.data( key ), val, "get: " + key );
+		deepEqual( div.data( jQuery.camelCase( key ) ), val, "get: " + jQuery.camelCase( key ) );
+	});
+});
+