Description
https://drafts.csswg.org/css2/#dynamic-effects
Contents of spanned rows and columns that intersect the collapsed column or row are clipped.
How exactly are they clipped? If for example I have a cell with text "A B C" spanning 3 columns, roughly each letter on a column, and the middle column is collapsed, am I supposed to see "A C"? Or clip at the end like "A B"?
The L3 spec isn't much clear either: https://drafts.csswg.org/css-tables/#visibility-collapse-track-rendering
When a table-track or table-track-group has visibility: collapse, all the backgrounds, borders or outlines that are contributed by the cells within the given table-track or table-track-group will continue to be painted on cells that have not been fully collapsed (because they spanned multiple tracks).
Here I have a more complete testcase:
<!DOCTYPE html>
<table border>
<col></col>
<col></col>
<col style="visibility: collapse"></col>
<col></col>
<col></col>
<tr>
<td>A1</td>
<td>A2</td>
<td>A3</td>
<td>A4</td>
<td>A5</td>
</tr>
<tr>
<td>B1</td>
<td colspan="3" rowspan="3">B2 B3 B4<br>C2 C3 C4<br>D2 D3 D4</td>
<td>B5</td>
</tr>
<tr style="visibility: collapse">
<td>C1</td>
<td>C5</td>
</tr>
<tr>
<td>D1</td>
<td>D5</td>
</tr>
<tr>
<td>E1</td>
<td>E2</td>
<td>E3</td>
<td>E4</td>
<td>E5</td>
</tr>
</table>| Gecko | Blink | Servo | |
|---|---|---|---|
 |
 |
 |
 |
No browser clips spanning cells at all!