Bug 42740 – When a cell that spans multiple columns has 'width' other than 'auto', the width of unrelated columns may be affected incorrectly

• Component: Tables
• Status: NEW

[Yuxiang Luo]

Created attachment 62163 [details]
A test case showing the wrong layout with the bug

When a cell with width other than 'auto' spans multiple columns, if the minimum widths of (some of) the columns that it spans need to be increased, unrelated columns with 'auto' width will also be increased which is not expected. For example:

<table cellpadding="0" cellspacing="0">
    <tr>
        <td>td0</td>
        <td>td1</td>
        <td id="td2" style="width:100px">td2</td>
    </tr>
    <tr>
        <td>td3</td>
        <td id="td4" style="width:200px" colspan="2">td4</td>
    </tr>
</table>

The expected widths should be:
  td0, td3: x (max of minimum widths of 'td0' and 'td3')
  td1: 100
  td2: 100
  td4: 200

The actual widths are:
  td0, td3: x + 25
  td1: 75
  td2: 100
  td4: 175

That is, the width of unrelated column (td0/td3) is also increased.
But this bug won't occur if:
1. the width of the cell itself that spans columns need to be increased, but not the columns that the cell spans
2. if unrelated column's width is not 'auto'. For example above, if either td0 or td3 has width other than 'auto', the bug doesn't occur

[Yuxiang Luo]

Environment:
Google Chrome 6.0.466.0 (Official Build 52279) dev
WebKit 534.3

[Ahmad Saleem]

Following updated test results:

*** Safari Technology Preview 153 ***

black cell width : 45
red cell width : 75
blue cell width : 100
gold cell width : 175

*** Chrome Canary 107 ***

black cell width : 20
red cell width : 100
blue cell width : 100
gold cell width : 200

*** Firefox Nightly 106 ***

black cell width : 20
red cell width : 100
blue cell width : 100
gold cell width : 200

_____

Changing the status to "New" and tagging others for their input. Thanks!

[Radar WebKit Bug Importer]

<rdar://problem/99781036>