Dimensions: properly manipulate non-px values

Fixes gh-1712
Close gh-2695

1 files changed, 19 insertions, 9 deletions

diff --git a/src/css.js b/src/css.js
index 0e5a55610..acd4bb3eb 100644
--- a/src/css.js
+++ b/src/css.js
@@ -27,8 +27,6 @@ var
 	// except "table", "table-cell", or "table-caption"
 	// See here for display values: https://developer.mozilla.org/en-US/docs/CSS/display
 	rdisplayswap = /^(none|table(?!-c[ea]).+)/,
-	rnumsplit = new RegExp( "^(" + pnum + ")(.*)$", "i" ),
-
 	cssShow = { position: "absolute", visibility: "hidden", display: "block" },
 	cssNormalTransform = {
 		letterSpacing: "0",
@@ -59,11 +57,14 @@ function vendorPropName( name ) {
 }
 
 function setPositiveNumber( elem, value, subtract ) {
-	var matches = rnumsplit.exec( value );
+
+	// Any relative (+/-) values have already been
+	// normalized at this point
+	var matches = rcssNum.exec( value );
 	return matches ?
 
 		// Guard against undefined "subtract", e.g., when used as in cssHooks
-		Math.max( 0, matches[ 1 ] - ( subtract || 0 ) ) + ( matches[ 2 ] || "px" ) :
+		Math.max( 0, matches[ 2 ] - ( subtract || 0 ) ) + ( matches[ 3 ] || "px" ) :
 		value;
 }
 
@@ -336,16 +337,25 @@ jQuery.each( [ "height", "width" ], function( i, name ) {
 		},
 
 		set: function( elem, value, extra ) {
-			var styles = extra && getStyles( elem );
-			return setPositiveNumber( elem, value, extra ?
-				augmentWidthOrHeight(
+			var matches,
+				styles = extra && getStyles( elem ),
+				subtract = extra && augmentWidthOrHeight(
 					elem,
 					name,
 					extra,
 					jQuery.css( elem, "boxSizing", false, styles ) === "border-box",
 					styles
-				) : 0
-			);
+				);
+
+			// Convert to pixels if value adjustment is needed
+			if ( subtract && ( matches = rcssNum.exec( value ) ) &&
+				( matches[ 3 ] || "px" ) !== "px" ) {
+
+				elem.style[ name ] = value;
+				value = jQuery.css( elem, name );
+			}
+
+			return setPositiveNumber( elem, value, subtract );
 		}
 	};
 } );