TYPO3 Core

The extension "linkhandler" allows to extends the link browser to select arbitrary records by creating new tabs within the link browser and integrating the regular record list view.
The selection of records fails after clicking the "show more" button of the record list view. The visible text within the input of the corresponding backend form link element changes, but the value of the hidden input element does not change to the value of the selected record.

The reason for this behavior is, that the "show more" button reloads the link browser and the function of "FormEngineLinkBrowserAdapter.updateFunctions" is empty.
That´s caused by a failed comparison of fieldChangeFuncHash when calling LinkBrowserController::areFieldChangeFunctionsValid().
The hash comparison fails, because in the process of generating the URI of the read more button GeneralUtility::implodeArrayForUrl() is called with $skipBlank = true, while the hash, which was copied from the request, was generated with the empty parameter "alert", so when checking the hash this parameter does no longer exist.

I think a good solution to avoid this problem is to not add the empty "alert" parameter in the first place, see the attached patch.