Resizable: correct width when grid approaches zero

Fixes #10590
(cherry picked from commit 9493839)

Author: mikesherov

tests/unit/resizable/resizable_options.js

@@ -311,12 +311,12 @@ test( "grid - maintains grid with padding and border when approaching no dimensi
 			height: 80
 		}).resizable({
 			handles: "all",
-			grid: 50
+			grid: [ 50, 12 ]
 		});
 
 	TestHelpers.resizable.drag( handle, 50, 50 );
 	equal( target.outerWidth(), 50, "compare width" );
-	equal( target.outerHeight(), 50, "compare height" );
+	equal( target.outerHeight(), 52, "compare height" );
 });
 
 test("ui-resizable-se { handles: 'all', minWidth: 60, minHeight: 60, maxWidth: 100, maxHeight: 100 }", function() {

ui/resizable.js

@@ -1165,7 +1165,7 @@ $.ui.plugin.add("resizable", "grid", {
 				that.size.width = newWidth;
 				that.position.left = op.left - ox;
 			} else {
-				newWidth = gridY - outerDimensions.height;
+				newWidth = gridX - outerDimensions.width;
 				that.size.width = newWidth;
 				that.position.left = op.left + os.width - newWidth;
 			}