DB/PreparedSQL: fix false positives with case-insensitive function names

The sniff was incorrectly flagging valid SQL escaping functions when they were
written with mixed or uppercase letters (e.g., 'Esc_Sql' instead of 'esc_sql').
This occurred because the function name comparison was case-sensitive when
checking against the predefined list of safe SQL escaping functions.

This fix ensures that function names are properly normalized to lowercase
before comparing them against the allowed escaping functions list, preventing
false positives regardless of the function name's capitalization.

Author: rodrigoprimo

WordPress/Sniffs/DB/PreparedSQLSniff.php

@@ -207,10 +207,11 @@ static function ( $symbol ) {
 			}
 
 			if ( \T_STRING === $this->tokens[ $this->i ]['code'] ) {
+				$content_lowercase = strtolower( $this->tokens[ $this->i ]['content'] );
 
 				if (
-					isset( $this->SQLEscapingFunctions[ $this->tokens[ $this->i ]['content'] ] )
-					|| isset( $this->SQLAutoEscapedFunctions[ $this->tokens[ $this->i ]['content'] ] )
+					isset( $this->SQLEscapingFunctions[ $content_lowercase ] )
+					|| isset( $this->SQLAutoEscapedFunctions[ $content_lowercase ] )
 				) {
 
 					// Find the opening parenthesis.

WordPress/Tests/DB/PreparedSQLUnitTest.1.inc

@@ -30,7 +30,7 @@ $all_post_meta = $wpdb->get_results( $wpdb->prepare( sprintf(
 ), $post_ids ) );
 
 $wpdb->query( "SELECT * FROM $wpdb->posts WHERE post_title LIKE '" . esc_sql( $foo ) . "';" ); // Ok.
-$wpdb->query( "SELECT * FROM $wpdb->posts WHERE ID = " . absint( $foo ) . ";" ); // Ok.
+$wpdb->query( "SELECT * FROM $wpdb->posts WHERE ID = " . ABSINT( $foo ) . ";" ); // Ok.
 
 // Test multi-line strings.
 $all_post_meta = $wpdb->get_results( $wpdb->prepare( sprintf(
@@ -79,7 +79,7 @@ $all_post_meta = $wpdb->get_results( $wpdb->prepare( sprintf( <<<'ND'
 		AND `post_id` IN (%s)
 ND
 	, $wpdb->postmeta,
-	IMPLODE( ',', array_fill( 0, count( $post_ids ), '%d' ) )
+	IMPLODE( ',', array_fill( 0, COUNT( $post_ids ), '%d' ) )
 ), $post_ids ) ); // OK.
 
 wpdb::prepare( "SELECT * FROM $wpdb?->posts WHERE post_title LIKE '" . foo() . "';" ); // Bad.