Inline Format missing in Synced Pattern with Paragraph and heading Overrides (WP 6.9)

[sunmorgn]

Description

n WordPress 6.9, blocks with Enable Overrides active within Synced Patterns no longer support inline "Format Types" (e.g., custom text colors, strikethrough, subscript). Previously, thus was allowed. Now, the rich text toolbar is completely removed for overridden blocks. This removal breaks existing website functionality and design consistency from previous websites.

Step-by-step reproduction instructions

1. Create a Synced Pattern containing a Paragraph or Heading block.
2. In the block's Advanced settings, toggle "Enable Overrides".
3. Insert this pattern into a new Page.
4. Attempt to highlight a single word in the overridden block to apply strikethrough for example.
5. Observe: The toolbar options for these specific inline formats are missing.

Screenshots, screen recording, code snippet

No response

Environment info

WP 6.9

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[t-hamano]

Thanks for the report.

This certainly seems like a regression: the More dropdown disappears, and only the formats shown by default in the toolbar are available.

WP 6.8

WP 6.9 or Latest Gutenberg

[talldan]

I think this might be an intentional change as a result of #71058, but I don't know the full story behind it. (cc @getdave )

[t-hamano]

I've identified the actual problem as #72043, i.e. this line:

https://github.com/WordPress/gutenberg/pull/72043/changes#diff-bec072c72a2f961596701aef67f67575b0a3b918135a6587229a0cd79bb3db44L357

However, this change only exposed a potential problem, and I believe the underlying issue lies in #71058.

Since there is no longer Write Mode, should we remove the private key and disableNoneEssentialFormatting introduced by #71058?

cc @Mamaduka @jeryj @scruffian

[talldan]

It does still seem like it was intentional based on the PR description:

Reduces editing tools to essential only in contentOnly mode so e.g. a Paragraph inside a pattern only has basic tools now:

There's some similar commentary here from the earlier PR - #71058 (comment).

I guess specifically for synced pattern overrides, it does make it impossible to add some of those formats (other uses of contentOnly mode usually allow for switching off contentOnly).

[t-hamano]

I don't understand the full details behind the PR, but the main issue is that the functionality is a private API implemented via Symbol, so there's no way for consumers to mark their formats as "Essential".

I personally lean towards removing this private API until the contentOnly spec is a bit more stable.