Regression in 6.7.2 - undefined index error

[fisharebest]

Upgrading from 6.6.5 to 6.7.2 causes an undefined index error in my test scripts.

ErrorException: Undefined array key -1

/Users/gr4376/Projects/webtrees/vendor/tecnickcom/tcpdf/tcpdf.php:18829
/Users/gr4376/Projects/webtrees/vendor/tecnickcom/tcpdf/tcpdf.php:5934

The offending code is $dom[$key-1].

18829                 if ($ln AND (!($cell AND ($dom[$key-1]['value'] == 'table')))) {
18830                         $this->Ln($this->lasth);
18831                         if (($this->y < $maxbottomliney) AND ($startlinepage == $this->page)) {
18832                                 $this->y = $maxbottomliney;
18833                         }
18834                 }

Using git bisect, I have traced the issue to this commit. Removing this change allows the 6.7.2 code to run without error.

$ git diff 883cbb44093bf9d2ed47a2ada457ff3368eb0661..1ae5c4721cecb6be1fa1c0bebb506ed454a3e02d
diff --git a/tcpdf.php b/tcpdf.php
index 51e3c2f..1df2246 100644
--- a/tcpdf.php
+++ b/tcpdf.php
@@ -16389,6 +16389,9 @@ class TCPDF {
         * @since 3.2.000 (2008-06-20)
         */
        protected function getHtmlDomArray($html) {
+               if(empty($html)) {
+                       return array();
+               }
                // array of CSS styles ( selector => properties).
                $css = array();
                // get CSS array defined at previous call

Debugging shows that when the $html parameter is an empty string, then the returned array would otherwise be non-empty. For example, this:

array (
  0 => 
  array (
    'tag' => false,
    'block' => false,
    'value' => '',
    'parent' => 0,
    'hide' => false,
    'fontname' => 'dejavusans',
    'fontstyle' => '',
    'fontsize' => 8.0,
    'font-stretch' => 100,
    'letter-spacing' => 0,
    'stroke' => 0,
    'fill' => true,
    'clip' => false,
    'line-height' => 1.25,
    'bgcolor' => false,
    'fgcolor' => 
    array (
      'R' => 0,
      'G' => 0,
      'B' => 0,
    ),
    'strokecolor' => 
    array (
      'R' => 0,
      'G' => 0,
      'B' => 0,
    ),
    'align' => '',
    'listtype' => '',
    'text-indent' => 0,
    'text-transform' => '',
    'border' => 
    array (
    ),
    'dir' => 'ltr',
  ),
)

We previously returned an array with a key of 0; we are now returning an empty array. Hence we are getting this error.

Elsewhere in the code, I see dependencies on other elements in this array.

I can "fix" the PHP errors by replacing return array() in the change with return array(array('tag'=>false,'value'=>'')).

However, there may be subtle functional changes that I'm missing.

[nicolaasuni]

Please check the version 6.7.3 it should be fixed now.