CSV Delimiter Counting not respecting quoted strings

[zmears]

This is:

- [X ] a bug report

What is the expected behavior?

When counting delimiters the CSV Reader class should respect enclosed strings and only count potential delimiters outside of enclosed strings.

What is the current behavior?

The csv reader counts any appearance of a delimiter.

What are the steps to reproduce?

Parse this csv:

"Date/Time","task","username"
"12/17/2017 14:35","viewpage","username1",
"12/17/2017 04:00","editpage","username5",
"11/29/2017 08:20","deletepage","username2",,

Output:

array (size=4)
  0 => 
    array (size=1)
      0 => string 'Date/Time,"task","username"' (length=27)
  1 => 
    array (size=1)
      0 => string '12/17/2017 14:35,"viewpage","username1",' (length=40)
  2 => 
    array (size=1)
      0 => string '12/17/2017 04:00,"editpage","username5",' (length=40)
  3 => 
    array (size=1)
      0 => string '11/29/2017 08:20,"deletepage","username2",,' (length=43)

Which versions of PhpSpreadsheet and PHP are affected?

dev/master - php 7.0

Potential Fix

Remove any quoted strings from the line before counting delimiters.

PhpOffice\PhpSpreadsheet\Reader

while (($line = fgets($this->fileHandle)) !== false && (++$numberLines < 1000)) {
            $countLine = [];
            for ($i = strlen($line) - 1; $i >= 0; --$i) {
...

to

while (($line = fgets($this->fileHandle)) !== false && (++$numberLines < 1000)) {
            $line = preg_replace('/('.$this->enclosure.'.*'.$this->enclosure.')/U', '', $line);
            $countLine = [];
            for ($i = strlen($line) - 1; $i >= 0; --$i) {
...

I am not sure if this will work with all possible enclosures, or if the enclosures are malformed.