1416504 - FF left table border disappears when wrapper's overflow-x is auto

Status: UNCONFIRMED

(Core :: Layout: Tables, defect, P3)

Description

[vaxquis]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce:

When using a table with bordered cells, in FireFox the left table border disappears when the table is placed in wrapper with `overflow-x: auto`.

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-html -->

    <div style="overflow-x:auto">
      <table style="border-collapse:collapse">
        <tr>
          <td style="border: none;"></td>
        </tr>
        <tr>
          <td style="border: 1px solid black;">a</td>
        </tr>
      </table>
    </div>

<!-- end snippet -->

(also [here](https://jsfiddle.net/zpwugncq/))

[A possible workaround I found:](https://jsfiddle.net/u4e9pz9o/)

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-html -->

    <div style="overflow-x:auto; padding-left: 1px">
      <table style="border-collapse:collapse">
        <tr>
          <td style="border: none;"></td>
        </tr>
        <tr>
          <td style="border: 1px solid black;">a</td>
        </tr>
      </table>
    </div>

<!-- end snippet -->

This does happen on every FireFox version beginning from 4 (and possible earlier) up to 56. This behaviour seems totally specific to FF, as I wasn't able to reproduce it any version of IE, Opera, Safari, Android Browser or Chrome (even IE9 conforms here!). I couldn't find [any bug report](https://bugzilla.mozilla.org/buglist.cgi?component=Layout%3A%20Tables&product=Core&bug_status=__open__) directly mentioning this situation (only table rendering bug that is still open [albeit after 6 years *chuckles*] is [#688556](https://bugzilla.mozilla.org/show_bug.cgi?id=688556), but it concerns background painting, which is obviously not this case).

On SO @ https://stackoverflow.com/questions/47228806/ff-left-table-border-disappears-when-wrappers-overflow-x-is-auto for reference.


Actual results:

Left border disappears.


Expected results:

Left border should stay visible.

Comment 1

[vaxquis]

As a side note: the simplest workaround is to provide a left padding of width equal to int( 0.5 * ( left_border_width + 1 ) ). The fact that the needed padding has to be half the size of the border is disturbing at best and may suggest a problem with border-collapse interpretation.