"Save Block"-button on Add New Block silently ignores clicks if the content is empty.

[geon]

When clicking "Save Block", nothing happens if the content editor is empty.

Preconditions

Magento: 2.1.2, 2.1.3
PHP: 7
Mysql: Percona
(Mageinferno docker-compose)

Steps to reproduce

1. Go to Content > Blocks > Add New Block
2. Fill in Block Title and Identifier
3. Click "Save Block"

Expected result

Block saved with empty content, or error message displayed.

Actual result

Nothing. Click is ignored.

[magento-engcom-team]

@geon, thank you for your report.
We've created internal ticket(s) MAGETWO-80459 to track progress on the issue.