[css-grid] Grid Item Placement Algorithm: Step 3

Hi,

regarding 3rd step of placement algorithm: "Determine the number of
columns in the implicit grid". I think there's a mistake in "the largest
positive column-end line index, minus 1".

This was ok when the implicit tracks could only be added after the
explicit grid, but now that the spec allows to add implicit tracks
before the explicit grid this is not true anymore.

So for example, imagine that we've a 2 columns grid, the lines would be
something like this:
  |---|---|
         1   2   3

But when you place an item using "grid-column: -5;" it'd add 2 new
columns before the explicit grid. The lines would be:
  |---|---|---|---|
                 1   2   3
  -5  -4  -3  -2  -1

So, if we've any auto-positioned items, when we need to calculate the
number of columns, we should consider that it's 4. That's not the
"largest positive column-end line". I guess this should be the distance
between the left and right definite lines (not sure about the right
wording for this).

Bye,
  Rego

Received on Thursday, 5 November 2015 15:15:41 UTC