WordPress Post Edit Screen Content Overflow Issue in version 7.0 RC2

[Pratik Jain]

In WordPress 7.0 RC2 version,
At Post Add / Edit Scrren (Wheather It is Built-in Post Type or Custom Post Type) the content after the page heading is coming out of wrapping container.

[Pratik Jain]

Normal Scrren

[Pratik Jain]

Overflow when we closly examine it

[Pratik Jain]

I checked it and I can see below CSS is causing it,

#poststuff #post-body {
  padding: 0;
  margin: 0 -4px;
}

padding: 4px was added to .meta-box-sortables to give drag-and-drop drop zones a small inset for the new rounded corners. To counteract it, a margin: 0 -4px was added to #poststuff #post-body which caused content to overflow its container on the post Add/Edit screen.

As padding is needed during dragging, so moved it inside the existing .is-dragging-metaboxes selector and removed the compensating negative margin.

Trac ticket: #65018

[abcd95]

Test Report

Description

This report validates that the proposed patch resolves the content overflow issue observed on the Post Add/Edit screen.

Patch tested: ​https://patch-diff.githubusercontent.com/raw/WordPress/wordpress-develop/pull/11437.diff

Environment

WordPress: 7.1-alpha-62161-src
PHP: 8.3.30
Server: nginx/1.29.5
Database: mysqli (Server: 8.4.8 / Client: mysqlnd 8.3.30)
Browser: Chrome 146.0.0.0
OS: macOS
Theme: Twenty Twenty-Five 1.4
Plugins:
Test Reports 1.2.0

Steps to Reproduce

Navigate to Media → edit.
Observe layout behavior below the page heading.
Apply the patch.
Reload the Post Add/Edit screen.

Actual Results

Before patch: Content overflows outside the wrapping container below the page heading.
After patch: Content is properly contained within the layout boundaries.
✅ Issue resolved with the patch.

Additional Notes

The fix correctly restores layout containment without introducing any visible UI regressions.
Verified across both default and custom post types.

Supplemental Artifacts

Screenshot of the fixed contained layout -

[rshultz1]

Tested the attached patch on a LocalWP environment on Windows.

Environment:

WordPress 7.0 RC2
LocalWP on Windows 11
PHP 8.2.x
Browser: Chrome 135
Theme: Twenty Twenty-Five
Screen size: 1366×768

Steps to reproduce:

1. Open the post edit screen (/wp-admin/post.php).
2. Drag metaboxes such as Categories or Tags.
3. Observe horizontal overflow and layout shifting during drag.

Results before patch:

Horizontal overflow occurs.
Layout shifts while dragging metaboxes.

Results after applying patch:

Overflow issue is resolved.
No horizontal scrolling during drag.
Layout remains stable while moving metaboxes.

Patch applies and fixes the issue as expected in this Windows LocalWP test environment.

Patch tested:​https://patch-diff.githubusercontent.com/raw/WordPress/wordpress-develop/pull/11437.diff

[gaisma22]

Patch Testing Report

Patch Tested: ​https://github.com/WordPress/wordpress-develop/pull/11437

Environment

• WordPress: 7.0-beta6-62085-src
• PHP: 8.3.30
• Server: nginx/1.29.7
• Database: MySQL 8.4.8
• Browser: Brave
• OS: Ubuntu 24.04
• Theme: Twenty Twenty-Five 1.4
• MU Plugins: None
• Plugins: Classic Editor 1.6.7

Steps Taken

1. Went to Posts > Add New on the classic editor screen.
2. Observed the layout below the page heading. Before patch: Content area overflows its container, visible as a red line on the left edge.
3. Applied PR #11437 and hard refreshed. After patch: Red line gone. Layout looks correct.

✅ Patch is solving the problem

Expected Result

The post edit screen content area should sit within its container with no horizontal overflow.

Additional Notes

1. Bug confirmed on WordPress 7.0-beta6 on the classic post edit screen.
2. Classic Editor plugin was required to reproduce the issue since the block editor does not show the same layout.

Screenshots/Screencast with results

Before Patch:

After Patch: