Simplify and document WP table names unquoting

Author: JanJakes

wp-includes/sqlite-ast/class-wp-sqlite-information-schema-reconstructor.php

@@ -202,11 +202,18 @@ private function get_wp_create_table_statements(): array {
 
 			$create_node = $ast->get_first_descendant_node( 'createStatement' );
 			if ( $create_node && $create_node->has_child_node( 'createTable' ) ) {
-				$name_node = $create_node->get_first_descendant_node( 'tableName' );
-				$name      = $this->unquote_mysql_identifier(
-					substr( $schema, $name_node->get_start(), $name_node->get_length() )
-				);
-
+				$name_node  = $create_node->get_first_descendant_node( 'tableName' );
+				$name_value = substr( $schema, $name_node->get_start(), $name_node->get_length() );
+
+				/*
+				 * Unquote the table name.
+				 *
+				 * For WordPress Core tables, this naive approach is sufficient,
+				 * as WordPress doesn't use any special characters in table names,
+				 * nor does it allow them in the WPDB prefix, in order to permit
+				 * inlining them in SQL, such as "SELECT * FROM {$wpdb->blogs}".
+				 */
+				$name               = trim( $name_value, '`"' );
 				$wp_tables[ $name ] = $create_node;
 			}
 		}
@@ -651,21 +658,4 @@ private function escape_mysql_string_literal( string $literal ): string {
 		// See: https://www.php.net/manual/en/mysqli.real-escape-string.php
 		return "'" . addcslashes( $literal, "\0\n\r'\"\Z" ) . "'";
 	}
-
-	/**
-	 * Unquote a quoted MySQL identifier.
-	 *
-	 * Remove bounding quotes and replace escaped quotes with their values.
-	 *
-	 * @param  string $quoted_identifier The quoted identifier value.
-	 * @return string                    The unquoted identifier value.
-	 */
-	private function unquote_mysql_identifier( string $quoted_identifier ): string {
-		$first_byte = $quoted_identifier[0] ?? null;
-		if ( '"' === $first_byte || '`' === $first_byte ) {
-			$unquoted = substr( $quoted_identifier, 1, -1 );
-			return str_replace( $first_byte . $first_byte, $first_byte, $unquoted );
-		}
-		return $quoted_identifier;
-	}
 }