Bug 205733 – Unitless zero should not always be allowed

• Status: RESOLVED
• Resolution: CONFIGURATION CHANGED
• Component: CSS

[Simon Fraser (smfr)]

inline bool shouldAcceptUnitlessValue(double value, CSSParserMode cssParserMode, UnitlessQuirk unitless)
{
    // FIXME: Presentational HTML attributes shouldn't use the CSS parser for lengths
    return value == 0
        || isUnitLessValueParsingEnabledForMode(cssParserMode)
        || (cssParserMode == HTMLQuirksMode && unitless == UnitlessQuirk::Allow);
}

Note the "value == 0". This is wrong; unitless zero should only be accepted in some legacy situations. See https://www.w3.org/TR/css3-values/#angles and related.

[Ahmad Saleem]

This FIXME is present but the code is bit changed.

https://github.com/WebKit/WebKit/blob/10224b907dbca4a066401003bd0734bdefbadf1c/Source/WebCore/css/parser/CSSPropertyParserHelpers.cpp#L93

Is this still required? Thanks!

[Anne van Kesteren]

Comment 0 is addressed due to:

    (value == 0 && unitlessZero == UnitlessZeroQuirk::Allow)

I.e., comparison to 0 is no longer done unconditionally.

The FIXME is a separate issue and sounds like it relates to callers of this method. Best tackled separately.