CSS Conflict Fix Between WPSlug and Plugins Like All-in-One WP Migration

WordPress
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Issue

The sanitize_title filter (priority 9) in WPSlug (Wen Pai Su Ge) intercepts WordPress core’s internal sanitize_title() call inside add_menu_page(). WordPress uses this call to generate the admin page hook suffix ($admin_page_hooks[$menu_slug]).

When All-in-One WP Migration (AIOWPM) registers its menu via add_menu_page('All-in-One WP Migration', ...), the following occurs:

  • Without WPSlug: hook suffix = all-in-one-wp-migration :white_check_mark: (correct)
  • With WPSlug: the optimizer removes stop words such as "in" → hook suffix = all-one-wp-migration :cross_mark: (incorrect)

AIOWPM’s enqueue_import_scripts_and_styles($hook) performs a strict stripos match against the string all-in-one-wp-migration_page_ai1wm_import. The altered hook fails this match → CSS/JS assets are not enqueued → the import page loses all styling.

Scope of impact: Not limited to AIOWPM — any plugin whose menu title contains stop words (in, on, at, to, for, of, with, by, a, an, the) is affected.

Root Cause Analysis

WordPress uses sanitize_title() for two distinct purposes:

  1. Content slug generation: Used when saving posts, terms, or media — requires pinyin conversion and stop-word optimization.
  2. Internal identifier generation: Called by add_menu_page() during the admin_menu action to generate the hook suffix for page identification.

WPSlug does not distinguish between these two contexts, causing internal identifiers to be incorrectly optimized.

Fix Proposal

Add a guard condition in processSanitizeTitle() using doing_action() to skip processing during admin menu registration:

// Skip during admin menu registration — sanitize_title() is used to
// generate hook suffixes, not content slugs.
if (doing_action('admin_menu') || doing_action('network_admin_menu') || doing_action('user_admin_menu')) {
    return $title;
}

Why This Is Safe

  • add_menu_page() calls sanitize_title() during the admin_menu action solely to generate hook suffixes — these are not content slugs and must remain unaltered.
  • Actual post/term slug saving never occurs during the admin_menu action — thus zero false positives.
  • Coverage extends to network_admin_menu and user_admin_menu, ensuring safety in Multisite environments.

Verification Results

Tested on the wapuu.com staging site with both WPSlug and AIOWPM enabled:

  • During admin_menu: sanitize_title("All-in-One WP Migration") → all-in-one-wp-migration :white_check_mark: ("in" preserved)
  • Hook fully matches all-in-one-wp-migration_page_ai1wm_import :white_check_mark:
  • Regression test: Chinese slug conversion remains unaffected :white_check_mark: