[BUGFIX] Allow to add type=0 to typolink syntax

In previous versions, it was possible to link
to type=0 via "4,0,&param=2" where this was
stripped away, as the old syntax with the third
parameter was not supported anymore.

The patch changes the "empty()" to "isset()"
and explicitly sets the type parameter again.

Resolves: #81226
Releases: master, 9.5, 8.7
Change-Id: I5d19c38c90571f6686e7121dac638342783237ec
Reviewed-on: https://review.typo3.org/59299
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>

typo3/sysext/core/Classes/LinkHandling/LegacyLinkNotationConverter.php

@@ -174,6 +174,7 @@ protected function resolvePageRelatedParameters(string $data): array
             $result['pageuid'] = 'current';
             $result['fragment'] = substr($data, 1);
         } elseif (strpos($data, ',') !== false) {
+            $data = rtrim($data, ',');
             list($result['pageuid'], $result['pagetype']) = explode(',', $data, 2);
         } elseif (strpos($data, '/') !== false) {
             $data = explode('/', trim($data, '/'));

typo3/sysext/core/Classes/LinkHandling/PageLinkHandler.php

@@ -42,7 +42,8 @@ public function asString(array $parameters): string
             $urn .= '?uid=' . $parameters['pageuid'];
         }
         $urn = rtrim($urn, ':');
-        if (!empty($parameters['pagetype'])) {
+        // Page type is set and not empty (= "0" in this case means it is not empty)
+        if (isset($parameters['pagetype']) && strlen((string)$parameters['pagetype']) > 0) {
             $urn .= '&type=' . $parameters['pagetype'];
         }
         if (!empty($parameters['parameters'])) {

typo3/sysext/core/Tests/Unit/LinkHandling/LegacyLinkNotationConverterTest.php

@@ -76,6 +76,27 @@ public function resolveParametersForNonFilesDataProvider(): array
                 ],
                 't3://page?uid=13&type=31&unbel=ievable#uncool'
             ],
+            'page with type and parameters as another parameter and fragment - old style' => [
+                '13,31,&unbel=ievable&but=possibly#uncool',
+                [
+                    'type' => LinkService::TYPE_PAGE,
+                    'pageuid' => '13',
+                    'pagetype' => '31',
+                    'parameters' => 'unbel=ievable&but=possibly',
+                    'fragment' => 'uncool'
+                ],
+                't3://page?uid=13&type=31&unbel=ievable&but=possibly#uncool'
+            ],
+            'page with type and parameters as third parameter and explicitly allow type=0' => [
+                '1,0,&param=2',
+                [
+                    'type' => LinkService::TYPE_PAGE,
+                    'pageuid' => '1',
+                    'pagetype' => '0',
+                    'parameters' => 'param=2',
+                ],
+                't3://page?uid=1&type=0&param=2'
+            ],
             'page with alias - old style' => [
                 'alias13',
                 [