Forum

Hello, I found a border color bug, here is my analysis :

My php tail is regularly filled with php warning.

PHP Warning:  Trying to access array offset on value of type null in /var/www/[...]/PhpDocx/classes/DOMPDF_lib.php on line 4400

After some research, i found that the origin of the bug is due to a malformed html

<table class="MsoNormalTable" style="width: 16cm; margin-left: 5.4pt;" width="100%" cellspacing="0" cellpadding="0">
   <tbody>
      <tr style="height: 17pt;">
         <td style="width: 16cm; border: 1pt solid windowtext; padding: 0cm 5.4pt;">
            <p style="margin: 0cm 0cm 0.0001pt 1.7pt; font-size: 12pt; font-family: Arial, sans-serif;"><strong><span style="font-size: 11pt;">N° 2021-07-41</span></strong></p>
         </td>
      </tr>
   </tbody>
</table>

and more precisely le td style border: 1pt solid windowtext;, you noticed windowtext is not a valid css color.

In search of a correction, I found that the warning is launched when calling the protected function _get_border in classes\DOMPDF_lib.php

protected function _get_border($side) {
    $color = $this->__get("border_" . $side . "_color"); // Returns null

    return $this->__get("border_" . $side . "_width") . " " .
      $this->__get("border_" . $side . "_style") . " " . $color["hex"]; // Php warning because $color is null
  }

I thought of

if (!(isset($color) && is_array($color) && isset($color['hex']))) {
    $color = ['hex' => "#000000"];
}

This correction was not very clean, so I looked for another solution.
 

Do you remember windowtext is not a valid color ? So i looked for a parent function that will handle colors, and i found munge_colour in classes\DOMPDF_lib.php
In this function, there is a cascade of if and else if, but no if, si when the color is invalid or unrecognized, the function returns nothing, _get_border therefore has a variable of the wrong type

I propose as a correction to add another else if in the function munge_colour

[...] else if($colour !== "inherit") {
    return $this->getArray("000000");
}

Regards.