fixup! CSS: Warn and fill jQuery.cssNumber and .css(name, Number)

Author: mgol

src/css.js

@@ -83,16 +83,12 @@ if ( jQueryVersionSince( "3.4.0" ) && typeof Proxy !== "undefined" ) {
 	} );
 }
 
+// Create a dummy jQuery.cssNumber if missing. It won't be used by jQuery but
+// it will prevent code adding new keys to it unconditionally from crashing.
 if ( !jQuery.cssNumber ) {
 	jQuery.cssNumber = {};
 }
 
-// jQuery 3.x uses jQuery.cssNumber internally so we can't warn on access there.
-if ( jQueryVersionSince( "4.0.0" ) ) {
-	migrateWarnProp( jQuery, "cssNumber", jQuery.cssNumber,
-		"jQuery.cssNumber is deprecated" );
-}
-
 function isAutoPx( prop ) {
 
 	// The first test is used to ensure that:

test/css.js

@@ -117,19 +117,8 @@ QUnit.test( "jQuery.css with numbers", function( assert ) {
 
 } );
 
-QUnit[ jQueryVersionSince( "4.0.0" ) ? "test" : "skip" ]( "jQuery.cssNumber",
-		function( assert ) {
-	assert.expect( 3 );
-
-	expectWarning( assert, "Setting cssNumber value", 1, function() {
-		jQuery.cssNumber.blart = true;
-	} );
-
-
-	expectWarning( assert, "Getting cssNumber value", 1, function() {
-		assert.ok( jQuery.cssNumber.blart, "blart was set" );
-	} );
-
-	delete jQuery.cssNumber.blart;
+QUnit.test( "jQuery.cssNumber", function( assert ) {
+	assert.expect( 1 );
 
+	assert.ok( jQuery.cssNumber, "jQuery.cssNumber exists" );
 } );