Bug 118172 – Handling of Variables in StylePropertySet is broken

• Status: NEW
• Component: CSS

[Claudio Saavedra]

Any operation relying on StylePropertySet::findPropertyIndex(CSSPropertyID propertyID) to fetch data from a variable property will return always the last variable in the internal vector. This method is designed assuming that all properties have a different property ID, whereas all CSS custom properties share the CSSPropertyVariable ID.

For bug 117787 I'm adding an equivalent method, StylePropertySet::findVariableIndex(const AtomicString& variableName), but the existing StylePropertySet needs to be fixed to be able to distinguish when this should be used instead. I was tempted to add an assertion to findPropertyIndex:

    // This method assumes that there is only one property per type,
    // while there might be more than one CSSPropertyVariable property
    // present. findVariableIndex() should be used instead.
    ASSERT(propertyID != CSSPropertyVariable);

but I've noticed that there are plenty of uses of this that will need to be fixed, so I'll leave the assertion out.