Resizable: Store size based on calculated helper size to prevent 1 pixel shifts. Fixes #9547 - Resizable: off-by-one pixel dimensions with helper and grid

(cherry picked from commit 14065dc)

Author: kborchers

tests/unit/resizable/resizable_core.js

@@ -191,4 +191,19 @@ test("resizable accounts for scroll position correctly (#3815)", function() {
 	equal( el.css("top"), top, "css('top') stays the same when resized" );
 });
 
+test( "resizable stores correct size when using helper and grid (#9547)", function() {
+	expect( 2 );
+
+	var handle = ".ui-resizable-se",
+		target = $( "#resizable1" ).resizable({
+			handles: "all",
+			helper: "ui-resizable-helper",
+			grid: [ 10, 10 ]
+		});
+
+	TestHelpers.resizable.drag( handle, 1, 1 );
+	equal( target.width(), 100, "compare width" );
+	equal( target.height(), 100, "compare height" );
+});
+
 })(jQuery);

ui/jquery.ui.resizable.js

@@ -293,7 +293,7 @@ $.widget("ui.resizable", $.ui.mouse, {
 		//Store needed variables
 		this.offset = this.helper.offset();
 		this.position = { left: curleft, top: curtop };
-		this.size = this._helper ? { width: el.outerWidth(), height: el.outerHeight() } : { width: el.width(), height: el.height() };
+		this.size = this._helper ? { width: this.helper.width(), height: this.helper.height() } : { width: el.width(), height: el.height() };
 		this.originalSize = this._helper ? { width: el.outerWidth(), height: el.outerHeight() } : { width: el.width(), height: el.height() };
 		this.originalPosition = { left: curleft, top: curtop };
 		this.sizeDiff = { width: el.outerWidth() - el.width(), height: el.outerHeight() - el.height() };