From 13192d385f0f9f261ddf1ef50f43121e163a964b Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov@git.wordpress.org>
Date: Fri, 3 Nov 2023 15:31:51 +0000
Subject: [PATCH] Coding Standards: Remove unnecessary ignore annotation in
 `wp_kses_hair_parse()`.

It is perfectly possible to write a commented regex with layout for readability by using the `x` modifier.

As per the manual:
> x (`PCRE_EXTENDED`)
>
> If this modifier is set, whitespace data characters in the pattern are totally ignored except when escaped or inside a character class, and characters between an unescaped # outside a character class and the next newline character, inclusive, are also ignored. This is equivalent to Perl's /x modifier, and makes it possible to include commentary inside complicated patterns.
>
> Note, however, that this applies only to data characters. Whitespace characters may never appear within special character sequences in a pattern, for example within the sequence (?( which introduces a conditional subpattern.

Reference: [https://www.php.net/manual/en/reference.pcre.pattern.modifiers.php PHP Manual: Pattern Modifiers].

This commit rewrites these two regexes to use the `x` modifier and gets rid of the unnecessary `phpcs:disable` comments.

The tests in the `tests/phpunit/tests/db/dbDelta.php` file cover this change.

Follow-up to [42249].

Props jrf.
See #59650.

git-svn-id: https://develop.svn.wordpress.org/trunk@57056 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/kses.php | 47 ++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 23 deletions(-)

diff --git a/src/wp-includes/kses.php b/src/wp-includes/kses.php
index 27da1679e8..7449d8fb4a 100644
--- a/src/wp-includes/kses.php
+++ b/src/wp-includes/kses.php
@@ -1536,36 +1536,37 @@ function wp_kses_hair_parse( $attr ) {
 		return array();
 	}
 
-	// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation
 	$regex =
-		'(?:'
-		.     '[_a-zA-Z][-_a-zA-Z0-9:.]*' // Attribute name.
-		. '|'
-		.     '\[\[?[^\[\]]+\]\]?'        // Shortcode in the name position implies unfiltered_html.
-		. ')'
-		. '(?:'               // Attribute value.
-		.     '\s*=\s*'       // All values begin with '='.
-		.     '(?:'
-		.         '"[^"]*"'   // Double-quoted.
-		.     '|'
-		.         "'[^']*'"   // Single-quoted.
-		.     '|'
-		.         '[^\s"\']+' // Non-quoted.
-		.         '(?:\s|$)'  // Must have a space.
-		.     ')'
-		. '|'
-		.     '(?:\s|$)'      // If attribute has no value, space is required.
-		. ')'
-		. '\s*';              // Trailing space is optional except as mentioned above.
-	// phpcs:enable
+		'(?:
+				[_a-zA-Z][-_a-zA-Z0-9:.]* # Attribute name.
+			|
+				\[\[?[^\[\]]+\]\]?        # Shortcode in the name position implies unfiltered_html.
+		)
+		(?:                               # Attribute value.
+			\s*=\s*                       # All values begin with "=".
+			(?:
+				"[^"]*"                   # Double-quoted.
+			|
+				\'[^\']*\'                # Single-quoted.
+			|
+				[^\s"\']+                 # Non-quoted.
+				(?:\s|$)                  # Must have a space.
+			)
+		|
+			(?:\s|$)                      # If attribute has no value, space is required.
+		)
+		\s*                               # Trailing space is optional except as mentioned above.
+		';
 
 	/*
 	 * Although it is possible to reduce this procedure to a single regexp,
 	 * we must run that regexp twice to get exactly the expected result.
+	 *
+	 * Note: do NOT remove the `x` modifiers as they are essential for the above regex!
 	 */
 
-	$validation = "%^($regex)+$%";
-	$extraction = "%$regex%";
+	$validation = "%^($regex)+$%x";
+	$extraction = "%$regex%x";
 
 	if ( 1 === preg_match( $validation, $attr ) ) {
 		preg_match_all( $extraction, $attr, $attrarr );