Bug 142972 – CSSParser is encountering seemingly malformed scroll-snap-destination input

• Status: RESOLVED
• Resolution: INVALID
• Component: Layout and Rendering

[Brent Fulgham]

I placed the following assertion in CSSParser to catch instances where the scroll-snap-destination input processed by the CSSParser did not match expectations.

--- a/trunk/Source/WebCore/css/CSSParser.cpp
+++ b/trunk/Source/WebCore/css/CSSParser.cpp
@@ -3354,5 +3354,4 @@
 {
     RefPtr<CSSValueList> position = CSSValueList::createSpaceSeparated();
+    ASSERT(m_valueList->size() == 2);
     if (m_valueList->size() != 2)
         return false;

This is firing for the following test cases:

css3/scroll-snap/scroll-snap-position-values.html
css3/scroll-snap/scroll-snap-property-computed-style.html

[Radar WebKit Bug Importer]

<rdar://problem/20261950>

[Brent Fulgham]

It looks like we're hitting this for the invalid case 'none':

  -webkit-scroll-snap-destination: none;

The specification does not support 'none' as a valid input.

[Brent Fulgham]

The other case was expected bad input from 'scroll-snap-property-computed-style.js', which was passing three arguments to confirm we would reject it.

The assertion should not be used because of these known tests.

[Brent Fulgham]

These cases all work properly. The assertion I added was invalid. Closing as invalid.