[BUGFIX] Add more safety checks when dealing with buttons in the BE

This patch adds more sanity checks to the SplitButton when rendering
its items. Specifically the existence of getters is checked if those
are not part of the AbstractButton already.

Resolves: #89729
Releases: master, 9.5
Change-Id: I654238e1c9d606596348119374ac283dda1c1713
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62360
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Johannes Kasberger <johannes.kasberger@reelworx.at>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Johannes Kasberger <johannes.kasberger@reelworx.at>
Reviewed-by: Susanne Moog <look@susi.dev>

typo3/sysext/backend/Classes/Template/Components/Buttons/SplitButton.php

@@ -119,13 +119,9 @@ public function getButton()
     public function isValid()
     {
         $subject = $this->getButton();
-        if (isset($subject['primary'])
-            && ($subject['primary'] instanceof AbstractButton)
-            && isset($subject['options'])
-        ) {
-            return true;
-        }
-        return false;
+        return isset($subject['primary'])
+               && ($subject['primary'] instanceof AbstractButton)
+               && isset($subject['options']);
     }
 
     /**
@@ -139,13 +135,17 @@ public function render()
         $attributes = [
             'type' => 'submit',
             'class' => 'btn btn-sm btn-default ' . $items['primary']->getClasses(),
-            'name' => $items['primary']->getName(),
-            'value' => $items['primary']->getValue()
         ];
+        if (method_exists($items['primary'], 'getName')) {
+            $attributes['name'] = $items['primary']->getName();
+        }
+        if (method_exists($items['primary'], 'getValue')) {
+            $attributes['value'] = $items['primary']->getValue();
+        }
         if (!empty($items['primary']->getOnClick())) {
             $attributes['onclick'] = $items['primary']->getOnClick();
         }
-        if (!empty($items['primary']->getForm())) {
+        if (method_exists($items['primary'], 'getForm') && !empty($items['primary']->getForm())) {
             $attributes['form'] = $items['primary']->getForm();
         }
         $attributesString = '';
@@ -164,28 +164,37 @@ public function render()
             </button>
             <ul class="dropdown-menu">';
 
-        /** @var InputButton $option */
+        /** @var AbstractButton $option */
         foreach ($items['options'] as $option) {
-            $optionAttributes = [
-                'href' => '#',
-                'data-name' => $option->getName(),
-                'data-value' => $option->getValue(),
-                'data-form' => $option->getForm()
-            ];
-            if (!empty($option->getClasses())) {
-                $optionAttributes['class'] = $option->getClasses();
-            }
-            if (!empty($option->getOnClick())) {
-                $optionAttributes['onclick'] = $option->getOnClick();
-            }
-            $optionAttributesString = '';
-            foreach ($optionAttributes as $key => $value) {
-                $optionAttributesString .= ' ' . htmlspecialchars($key) . '="' . htmlspecialchars($value) . '"';
+            if ($option instanceof InputButton) {
+                // if the option is an InputButton we have to create a custom rendering
+                $optionAttributes = [
+                    'href' => '#',
+                    'data-name' => $option->getName(),
+                    'data-value' => $option->getValue(),
+                    'data-form' => $option->getForm()
+                ];
+
+                if (!empty($option->getClasses())) {
+                    $optionAttributes['class'] = $option->getClasses();
+                }
+                if (!empty($option->getOnClick())) {
+                    $optionAttributes['onclick'] = $option->getOnClick();
+                }
+                $optionAttributesString = '';
+                foreach ($optionAttributes as $key => $value) {
+                    $optionAttributesString .= ' ' . htmlspecialchars($key) . '="' . htmlspecialchars($value) . '"';
+                }
+                $html =  '<a' . $optionAttributesString . '>' . $option->getIcon()->render('inline') . ' '
+                    . htmlspecialchars($option->getTitle()) . '</a>';
+            } else {
+                // for any other kind of button we simply use what comes along (e.g. LinkButton)
+                $html = $option->render();
             }
+
             $content .= '
                 <li>
-                    <a' . $optionAttributesString . '>' . $option->getIcon()->render('inline') . ' '
-                    . htmlspecialchars($option->getTitle()) . '</a>
+                   ' . $html . '
                 </li>
             ';
         }