Summary

When 'limits' is set in CMS_PLACEHOLDER_CONF for particular plugin type within a placeholder, plugins are still counted after deletion. This was tested with limits=1 for a TextPlugin. A plugin was added, then deleted and finally adding another plugin was attempted but failed with a validation error: 'This placeholder already has the maximum number (1) of allowed Text plugins.'

Expected behaviour

Deleted plugins should no longer count toward the allowance of plugins that can be added to a placeholder.

Actual behaviour

After deleting a plugin it still counts toward the limit count.

Environment

• Python version: 3.5.2
• Django version: 1.8.18
• django CMS version: 3.4.4