Bug 148614 – Add support for the "unset" CSS property value

• Component: CSS
• Status: RESOLVED FIXED

[Chris Rebert]

It's part of CSS Cascading and Inheritance Level 3:
http://www.w3.org/TR/css-cascade-3/#inherit-initial

See also https://developer.mozilla.org/en-US/docs/Web/CSS/unset

Chrome and Firefox already support it, and it's "In Development" for Microsoft Edge.


Testcase: http://jsfiddle.net/cvrebert/1w6bhom0/

Testcase's HTML:
<div>A</div>
<div>B</div>
<div>C</div>

Testcase's CSS:
div {
    display: unset;/* in this case, same as inline */
}

[Radar WebKit Bug Importer]

<rdar://problem/22491420>

[Dave Hyatt]

Created attachment 263197 [details]
Patch

[WebKit Commit Bot]

Attachment 263197 [details] did not pass style-queue:


ERROR: Source/WebCore/css/CSSValue.h:49:  enum members should use InterCaps with an initial capital letter.  [readability/enum_casing] [4]
ERROR: Source/WebCore/css/CSSValue.h:50:  enum members should use InterCaps with an initial capital letter.  [readability/enum_casing] [4]
Total errors found: 2 in 23 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Dean Jackson]

Comment on attachment 263197 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=263197&action=review

> Source/WebCore/css/CSSParser.cpp:1951
> -
> +    

Oopsy.

> Source/WebCore/css/CSSUnsetValue.cpp:17
> + * Copyright (C) 2015 Apple Inc. All rights reserved.
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Library General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Library General Public License for more details.
> + *
> + * You should have received a copy of the GNU Library General Public License
> + * along with this library; see the file COPYING.LIB.  If not, write to
> + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
> + * Boston, MA 02110-1301, USA.

I thought we used this one for new files:

 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

Or maybe it doesn't matter.

[Dave Hyatt]

Fixed in r191151.

[yisibl]

http://trac.webkit.org/changeset/191151