Adding an emoji to a field layout Tip element causes broken JSON in the craft_fieldlayouttabs table

Description

Adding an emoji to a field layout Tip element and saving the field layout causes broken JSON in the elements column in the relevant craft_fieldlayouttabs table. Specifically, it appears that the JSON string is simply cut off, from the position where the emoji would be. See example broken JSON here.

Since the JSON is now invalid, attempting to render the relevant edit page for the field layout triggers an InvalidArgumentException (example stack trace for that error is here).

Steps to reproduce

1. Add a Tip element to a field layout, and add an emoji like 😉 to it
2. Save the field layout. It should save without any errors or exceptions
3. Navigate to the edit page using that layout. Get an InvalidArgumentException
4. Confirm that the JSON in the craft_fieldlayouttabs table is now truncated and invalid

Additional info

Only tested locally on macOS 10.14.6 using Valet.

• Craft version: 3.6.10
• PHP version: 7.4.13
• Database driver & version: MySQL 5.7.32
• Plugins & versions:

• Child Me! 1.2.0
• CP Clear Cache 1.1.0
• CP Field Inspect 1.2.4
• Image Resizer 2.1.0
• Imager X v3.3.0
• Redactor 2.8.5
• SEOMate 1.1.9

Start by reproducing the save and edit-page failure with an emoji in a Tip element, then inspect the truncated JSON in the elements column of the relevant craft_fieldlayouttabs row. Trace the field-layout save and render paths to identify where the JSON becomes invalid; done means the emoji remains intact, the stored JSON is valid, and the layout edit page renders successfully.