Bug: strMasterAlias false positive causes 500 error when module is embedded in a calendar event reader page

[luger95]

Bug report: strMasterAlias false positive when module is embedded in a calendar event reader page

Version: 1.32.52
Contao version: 4.13

Description

When a catalog-manager module (ModuleUniversalView) is inserted into a Contao calendar event reader page, a 500 error occurs.

The root cause is in the compile() method, at the condition:

$this->strMasterAlias && !$this->catalogPreventMasterView

On a calendar event reader page, the current URL contains the event alias. The module picks it up and assigns it to $this->strMasterAlias, then enters master view mode assuming the alias belongs to a catalog record. Since no catalog record matches the event alias, the module fails with a 500 error.

Steps to reproduce

1. Create a calendar event reader page in Contao 4.13.
2. Insert a catalog-manager universal view module on that page.
3. Open any calendar event URL (e.g. /events/my-event-alias.html).
4. A 500 error is thrown inside ModuleUniversalView::compile().

Expected behavior

The module should not enter master view mode unless the current alias actually matches a record in the catalog table. A non-catalog alias (such as a calendar event alias) should be ignored.

Suggested fix

Before entering master view mode, verify that the alias resolves to an existing catalog record:

if ($this->strMasterAlias && !$this->catalogPreventMasterView) {
    $objResult = \Database::getInstance()
        ->prepare("SELECT id FROM " . $this->catalogTablename . " WHERE alias = ? LIMIT 1")
        ->execute($this->strMasterAlias);

    if ($objResult->numRows < 1) {
        $this->strMasterAlias = null;
    }
}

This ensures the master view logic is only triggered when the alias genuinely belongs to the configured catalog table.

Happy to submit a pull request if this approach is confirmed.