Allow comma or semicolon separation in a list

This patch adds a new class, `AddressListParser`, with a single static
method `parse()`. It loops through each character of the value to
identify non-escaped, non-quoted delimiters, allowing either `,` or `;`
to be used.

`AbstractAddressList::fromString()` now uses the above method instead of
`str_getcsv()` to extract the list of addresses.

The patch also updates the test provided in zendframework#147 to test for the
existence of all addresses in the test string.

src/Header/AbstractAddressList.php

@@ -50,7 +50,7 @@ public static function fromString($headerLine)
         // split value on ","
         $fieldValue = str_replace(Headers::FOLDING, ' ', $fieldValue);
         $fieldValue = preg_replace('/[^:]+:([^;]*);/', '$1,', $fieldValue);
-        $values = str_getcsv($fieldValue, ',');
+        $values = AddressListParser::parse($fieldValue);
 
         $wasEncoded = false;
         array_walk(

src/Header/AddressListParser.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-mail for the canonical source repository
+ * @copyright Copyright (c) 2018 Zend Technologies USA Inc. (https://www.zend.com)
+ * @license   https://github.com/zendframework/zend-mail/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Mail\Header;
+
+use function in_array;
+
+class AddressListParser
+{
+    const CHAR_QUOTES = ['\'', '"'];
+    const CHAR_DELIMS = [',', ';'];
+    const CHAR_ESCAPE = '\\';
+
+    /**
+     * @param string $value
+     * @return array
+     */
+    public static function parse($value)
+    {
+        $values            = [];
+        $length            = strlen($value);
+        $currentValue      = '';
+        $inEscape          = false;
+        $inQuote           = false;
+        $currentQuoteDelim = null;
+
+        for ($i = 0; $i < $length; $i += 1) {
+            $char = $value[$i];
+
+            // If we are in an escape sequence, append the character and continue.
+            if ($inEscape) {
+                $currentValue .= $char;
+                $inEscape = false;
+                continue;
+            }
+
+            // If we are not in a quoted string, and have a delimiter, append
+            // the current value to the list, and reset the current value.
+            if (in_array($char, self::CHAR_DELIMS, true) && ! $inQuote) {
+                $values []= $currentValue;
+                $currentValue = '';
+                continue;
+            }
+
+            // Append the character to the current value
+            $currentValue .= $char;
+
+            // Escape sequence discovered.
+            if (self::CHAR_ESCAPE === $char) {
+                $inEscape = true;
+                continue;
+            }
+
+            // If the character is not a quote character, we are done
+            // processing it.
+            if (! in_array($char, self::CHAR_QUOTES)) {
+                continue;
+            }
+
+            // If the character matches a previously matched quote delimiter,
+            // we reset our quote status and the currently opened quote
+            // delimiter.
+            if ($char === $currentQuoteDelim) {
+                $inQuote = false;
+                $currentQuoteDelim = null;
+                continue;
+            }
+
+            // Otherwise, we're starting a quoted string.
+            $inQuote = true;
+            $currentQuoteDelim = $char;
+        }
+
+        // If we reached the end of the string and still have a current value,
+        // append it to the list (no delimiter was reached).
+        if ('' !== $currentValue) {
+            $values [] = $currentValue;
+        }
+
+        return $values;
+    }
+}

test/AddressListTest.php

@@ -128,5 +128,8 @@ public function testSemicolonSeparator()
         $addressList = $to->getAddressList();
 
         $this->assertEquals('Some User', $addressList->get('some.user@example.com')->getName());
+        $this->assertTrue($addressList->has('uzer2.surname@example.org'));
+        $this->assertTrue($addressList->has('asda.fasd@example.net'));
+        $this->assertTrue($addressList->has('root@example.org'));
     }
 }