[BUG] PageContent.DoesNotExist on first page via show_placeholder

[wfehr]

Description

When creating the first page, the show_placeholder-tag throws an exception.
If you "publish" the page via admin interface you can view/edit the page again without any problems.
(maybe only occurs if djangocms-versioning is used as well?)

Steps to reproduce

• fresh install with no created pages
• create a template containing "show_placeholder"
• create your first page -> throws error

Also reproducable with django-cms-quickstart on its main branch:

• insert show_placeholder "Content" request.current_page into minimal.html for example
• create first page
• first view of page works -> now change the template to "minimal" => error

Expected behaviour

should load the page without an exception.

Actual behaviour

throws "PageContent.DoesNotExist"-exception here because of the "get_placeholders"-call.

Additional information (CMS/Python/Django versions)

• django 5.x
• cms 5.x
• djangocms-versioning>=2.x

Do you want to help fix this issue?

• Yes, I want to help fix this issue and I will join the channel #pr-reviews on the Discord Server to confirm with the community that a PR is welcome.
• No, I only want to report the issue.

[fsbraun]

@wfehr Thanks for reporting this! IHMO the bug is two-fold:

• A non-existing placeholder should fail silently, e.g., if the page you refer to has no published content.
• In preview and edit mode, also unpublished content of the referred page should be taken into account (e.g., new install)

[fsbraun]

@wfehr Please be invited to check if the fix in #8272 works for you.

[wfehr]

@wfehr Please be invited to check if the fix in #8272 works for you.

Works with the given fix! 🥳