Using dash "-" character in template causes potential issue as described at #32621 . This PR adds validation to prevent using that character in template name. In general, we only accept Letters, numbers and underscore for template name as displayed in UI.
Testing Instructions
Go to System -> Site Templates -> Cassiopeia Details and Files
Click on Copy Template button in the toolbar to create a copy of the template
Enter a template name contains - character, for example test-template-name
Before patch: Template is created
After patch: Template could not be created, there is error message displayed Invalid template name. Please use only letters, numbers and underscores
I have tested this item✅ successfully on 407c5a3
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/34196.