Merge branch 'B7891ExtraButtonInfoTriggersRequiredWarning' into 'master'

Fixes #7891. Added missing 'type="button"' to button element

See merge request !208

extension/Classes/Core/Helper/HelperFormElement.php

@@ -375,7 +375,7 @@ class HelperFormElement {
         // INFO: $showinline =- TRUE ('input' elemente)
         if (isset($formElement[FE_INPUT_EXTRA_BUTTON_INFO]) && $showInline) {
             $extraButton .= <<<EOF
-            <button class="btn btn-info" onclick="$('#$id-extra-info').slideToggle('swing')">
+            <button type="button" class="btn btn-info" onclick="$('#$id-extra-info').slideToggle('swing')">
                 $infoSymbolInside
             </button>
 EOF;