[css3-text] Implement text-decoration property shorthand

Source/core/css/CSSParser-in.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 2100 matching lines @@
         validPrimitive = true;
         break;
     case CSSPropertyFontFamily:
         // [[ <family-name> | <generic-family> ],]* [<family-name> | <generic-family>] | inherit
     {
         parsedValue = parseFontFamily();
         break;
     }
 
     case CSSPropertyTextDecoration:
+        // Fall through to CSS2.1 implementation if runtime feature is disabled.
+        if (RuntimeEnabledFeatures::css3TextDecorationsEnabled()) {
+            // [ <text-decoration-line> || <text-decoration-style> || <text-decoration-color> ] | inherit
+            return parseShorthand(CSSPropertyTextDecoration, textDecorationShorthand(), important);
+        }
     case CSSPropertyWebkitTextDecorationsInEffect:
     case CSSPropertyTextDecorationLine:
         // none | [ underline || overline || line-through || blink ] | inherit
         return parseTextDecoration(propId, important);
 
     case CSSPropertyTextDecorationStyle:
         // solid | double | dotted | dashed | wavy
         if (RuntimeEnabledFeatures::css3TextDecorationsEnabled()
             && (id == CSSValueSolid || id == CSSValueDouble || id == CSSValueDotted || id == CSSValueDashed || id == CSSValueWavy))
             validPrimitive = true;
@@ skipping 6675 matching lines @@
             list->append(cssValuePool().createIdentifierValue(value->id));
             break;
         default:
             isValid = false;
             break;
         }
         if (isValid)
             value = m_valueList->next();
     }
 
-    if (list->length() && isValid) {
+    // Values are either valid or in shorthand scope.
+    if (list->length() && (isValid || inShorthand())) {

[Julien - ping for review, 2013/07/27 01:46:35]

Is it totally right to allow an empty list of keywords to be considered fine
here? (e.g. navy dotted row)

[abinader, 2013/07/28 04:21:52]

If I understood your question correctly, you are questioning whether doing the
following:

elem.style.textDecoration = "navy dotted"

Would be valid. So the answer is yes: according to the specification, "Omitted
values are set to their initial values." - in this case, the text decoration
line value is omitted, thus making it revert back to "initial", which is then
properly computed as "none". I'll add it to the
getComputedStyle-text-decoration-shorthand.html layout test for sanity check.

[Julien - ping for review, 2013/07/29 18:53:11]

Ah, that's not really what I meant (sorry for being unclear). Rereading the
logic, it's actually OK anyway: I was afraid we would accept non-valid
text-decoration-style values here due to the inShorthand() check.

[abinader, 2013/07/29 21:15:32]

Ah, I see your point now :) no, this function is not responsible for
text-decoration-style.

         addTextDecorationProperty(propId, list.release(), important);
         return true;
     }
 
     return false;
 }
 
 #if ENABLE(CSS3_TEXT)
 bool CSSParser::parseTextUnderlinePosition(bool important)
 {
@@ skipping 2846 matching lines @@
 {
     // The tokenizer checks for the construct of an+b.
     // However, since the {ident} rule precedes the {nth} rule, some of those
     // tokens are identified as string literal. Furthermore we need to accept
     // "odd" and "even" which does not match to an+b.
     return equalIgnoringCase(token, "odd") || equalIgnoringCase(token, "even")
         || equalIgnoringCase(token, "n") || equalIgnoringCase(token, "-n");
 }
 
 }