CSS: Support relative adjustment in any applicable unit

Fixes gh-1711
Closes gh-2011

(cherry picked from commit 9b03f6df88)

Conflicts:
	src/css.js
	src/effects.js

src/effects.js

@@ -1,8 +1,9 @@
 define([
 	"./core",
-	"./var/pnum",
+	"./var/rcssNum",
 	"./css/var/cssExpand",
 	"./css/var/isHidden",
+	"./css/adjustCSS",
 	"./css/defaultDisplay",
 
 	"./core/init",
@@ -11,65 +12,17 @@ define([
 	"./css",
 	"./deferred",
 	"./traversing"
-], function( jQuery, pnum, cssExpand, isHidden, defaultDisplay ) {
+], function( jQuery, rcssNum, cssExpand, isHidden, adjustCSS, defaultDisplay ) {
 
 var
 	fxNow, timerId,
 	rfxtypes = /^(?:toggle|show|hide)$/,
-	rfxnum = new RegExp( "^(?:([+-])=|)(" + pnum + ")([a-z%]*)$", "i" ),
 	rrun = /queueHooks$/,
 	animationPrefilters = [ defaultPrefilter ],
 	tweeners = {
 		"*": [ function( prop, value ) {
-			var tween = this.createTween( prop, value ),
-				target = tween.cur(),
-				parts = rfxnum.exec( value ),
-				unit = parts && parts[ 3 ] || ( jQuery.cssNumber[ prop ] ? "" : "px" ),
-
-				// Starting value computation is required for potential unit mismatches
-				start = ( jQuery.cssNumber[ prop ] || unit !== "px" && +target ) &&
-					rfxnum.exec( jQuery.css( tween.elem, prop ) ),
-				scale = 1,
-				maxIterations = 20;
-
-			if ( start && start[ 3 ] !== unit ) {
-				// Trust units reported by jQuery.css
-				unit = unit || start[ 3 ];
-
-				// Make sure we update the tween properties later on
-				parts = parts || [];
-
-				// Iteratively approximate from a nonzero starting point
-				start = +target || 1;
-
-				do {
-					// If previous iteration zeroed out, double until we get *something*
-					// Use a string for doubling factor so we don't accidentally see scale
-					// as unchanged below
-					scale = scale || ".5";
-
-					// Adjust and apply
-					start = start / scale;
-					jQuery.style( tween.elem, prop, start + unit );
-
-				// Update scale, tolerating zero or NaN from tween.cur()
-				// And breaking the loop if scale is unchanged or perfect,
-				// or if we've just had enough
-				} while (
-					scale !== (scale = tween.cur() / target) && scale !== 1 && --maxIterations
-				);
-			}
-
-			// Update tween properties
-			if ( parts ) {
-				start = tween.start = +start || +target || 0;
-				tween.unit = unit;
-				// If a +=/-= token was provided, we're doing a relative animation
-				tween.end = parts[ 1 ] ?
-					start + ( parts[ 1 ] + 1 ) * parts[ 2 ] :
-					+parts[ 2 ];
-			}
-
+			var tween = this.createTween( prop, value );
+			adjustCSS( tween.elem, prop, rcssNum.exec( value ), tween );
 			return tween;
 		} ]
 	};