Fix #12990. Don't add 'px' to column-count. Close gh-1050.

AUTHORS.txt

@@ -155,3 +155,5 @@ Marcel Greter <marcel.greter@ocbnet.ch>
 Matthias Jäggli <matthias.jaeggli@gmail.com>
 Yiming He <yiminghe@gmail.com>
 Devin Cooper <cooper.semantics@gmail.com>
+Bennett Sorbo <bsorbo@gmail.com>
+ 
\ No newline at end of file

src/css.js

@@ -155,6 +155,7 @@ jQuery.extend({
 
 	// Exclude the following css properties to add px
 	cssNumber: {
+		"columnCount": true,
 		"fillOpacity": true,
 		"fontWeight": true,
 		"lineHeight": true,

test/unit/css.js

@@ -823,11 +823,20 @@ if ( jQuery.fn.offset ) {
 	});
 }
 
-test("Do not append px to 'fill-opacity' #9548", function() {
-	expect( 1 );
+test("Do not append px (#9548, #12990)", function() {
+	expect( 2 );
+
+	var $div = jQuery("<div>").appendTo("#qunit-fixture");
 
-	var $div = jQuery("<div>").appendTo("#qunit-fixture").css("fill-opacity", 1);
-	equal( $div.css("fill-opacity"), 1, "Do not append px to 'fill-opacity'");
+	$div.css( "fill-opacity", 1 );
+	equal( $div.css("fill-opacity"), 1, "Do not append px to 'fill-opacity'" );
+
+	$div.css( "column-count", 1 );
+	if ( $div.css("column-count") ) {
+		equal( $div.css("column-count"), 1, "Do not append px to 'column-count'" );
+	} else {
+		ok( true, "No support for column-count CSS property" );
+	}
 });
 
 test("css('width') and css('height') should respect box-sizing, see #11004", function() {