Changeset 37583 for trunk/src/wp-admin/includes/upgrade.php

Timestamp:

05/27/2016 11:56:20 AM (10 years ago)

Author:

ocean90

Message:

Database: Normalize index definitions in dbDelta().

dbDelta() compares the index definitions against the result of SHOW INDEX FROM $table_name. This requires a specific format so indices are not unnecessarily re-created. This format wasn't ensured, until now.

• Parse the raw index definition to extract the type, name and columns so a normalized definition can be built (#20263, #34873).
• Standardize on uppercase types (#34871) and on 'KEY'. 'INDEX' is only a synonym for 'KEY'.
• Escape index names with backticks (#20263).
• Normalize columns: Ignore ASC and DESC definitions (#34959), remove whitespaces (#34869) and escape column names with backticks (#20263).
• Add backticks to all index change queries (#20263).

Props ocean90, pento, kurtpayne.
Fixes #20263, #34869, #34871, #34873, #34959.

File:

• trunk/src/wp-admin/includes/upgrade.php (modified) (6 diffs)

trunk/src/wp-admin/includes/upgrade.php

@@ -2185 +2185 @@
 
                 // For every field line specified in the query.
-                foreach ($flds as $fld) {
+                foreach ( $flds as $fld ) {
+                        $fld = trim( $fld, " \t\n\r\0\x0B," ); // Default trim characters, plus ','.
 
                         // Extract the field name.
-                        preg_match("|^([^ ]*)|", trim($fld), $fvals);
+                        preg_match( '|^([^ ]*)|', $fld, $fvals );
                         $fieldname = trim( $fvals[1], '`' );
                         $fieldname_lowercased = strtolower( $fieldname );
@@ -2203 +2204 @@
                                 case 'spatial':
                                         $validfield = false;
-                                        $indices[] = trim(trim($fld), ", \n");
+
+                                        /*
+                                         * Normalize the index definition.
+                                         *
+                                         * This is done so the definition can be compared against the result of a
+                                         * `SHOW INDEX FROM $table_name` query which returns the current table
+                                         * index information.
+                                         */
+
+                                        // Extract type, name and columns from the definition.
+                                        preg_match(
+                                                  '/^'
+                                                .   '(?P<index_type>'             // 1) Type of the index.
+                                                .       'PRIMARY\s+KEY|(?:UNIQUE|FULLTEXT|SPATIAL)\s+(?:KEY|INDEX)|KEY|INDEX'
+                                                .   ')'
+                                                .   '\s+'                         // Followed by at least one white space character.
+                                                .   '(?:'                         // Name of the index. Optional if type is PRIMARY KEY.
+                                                .       '`?'                      // Name can be escaped with a backtick.
+                                                .           '(?P<index_name>'     // 2) Name of the index.
+                                                .               '(?:[0-9a-zA-Z$_-]|[\xC2-\xDF][\x80-\xBF])+'
+                                                .           ')'
+                                                .       '`?'                      // Name can be escaped with a backtick.
+                                                .       '\s+'                     // Followed by at least one white space character.
+                                                .   ')*'
+                                                .   '\('                          // Opening bracket for the columns.
+                                                .       '(?P<index_columns>'
+                                                .           '.+?'                 // 3) Column names, index prefixes, and orders.
+                                                .       ')'
+                                                .   '\)'                          // Closing bracket for the columns.
+                                                . '$/im',
+                                                $fld,
+                                                $index_matches
+                                        );
+
+                                        // Uppercase the index type and normalize space characters.
+                                        $index_type = strtoupper( preg_replace( '/\s+/', ' ', trim( $index_matches['index_type'] ) ) );
+
+                                        // 'INDEX' is a synonym for 'KEY', standardize on 'KEY'.
+                                        $index_type = str_replace( 'INDEX', 'KEY', $index_type );
+
+                                        // Escape the index name with backticks. An index for a primary key has no name.
+                                        $index_name = ( 'PRIMARY KEY' === $index_type ) ? '' : '`' . $index_matches['index_name'] . '`';
+
+                                        // Parse the columns. Multiple columns are separated by a comma.
+                                        $index_columns = array_map( 'trim', explode( ',', $index_matches['index_columns'] ) );
+
+                                        // Normalize columns.
+                                        foreach ( $index_columns as &$index_column ) {
+                                                // Extract column name and number of indexed characters (sub_part).
+                                                preg_match(
+                                                          '/'
+                                                        .   '`?'                      // Name can be escaped with a backtick.
+                                                        .       '(?P<column_name>'    // 1) Name of the column.
+                                                        .           '(?:[0-9a-zA-Z$_-]|[\xC2-\xDF][\x80-\xBF])+'
+                                                        .       ')'
+                                                        .   '`?'                      // Name can be escaped with a backtick.
+                                                        .   '(?:'                     // Optional sub part.
+                                                        .       '\s*'                 // Optional white space character between name and opening bracket.
+                                                        .       '\('                  // Opening bracket for the sub part.
+                                                        .           '\s*'             // Optional white space character after opening bracket.
+                                                        .           '(?P<sub_part>'
+                                                        .               '\d+'         // 2) Number of indexed characters.
+                                                        .           ')'
+                                                        .           '\s*'             // Optional white space character before closing bracket.
+                                                        .        '\)'                 // Closing bracket for the sub part.
+                                                        .   ')?'
+                                                        . '/',
+                                                        $index_column,
+                                                        $index_column_matches
+                                                );
+
+                                                // Escape the column name with backticks.
+                                                $index_column = '`' . $index_column_matches['column_name'] . '`';
+
+                                                // Append the optional sup part with the number of indexed characters.
+                                                if ( isset( $index_column_matches['sub_part'] ) ) {
+                                                        $index_column .= '(' . $index_column_matches['sub_part'] . ')';
+                                                }
+                                        }
+
+                                        // Build the normalized index definition and add it to the list of indices.
+                                        $indices[] = "{$index_type} {$index_name} (" . implode( ',', $index_columns ) . ")";
+
+                                        // Destroy no longer needed variables.
+                                        unset( $index_column, $index_column_matches, $index_matches, $index_type, $index_name, $index_columns );
+
                                         break;
                         }
-                        $fld = trim( $fld );
 
                         // If it's a valid field, add it to the field array.
                         if ( $validfield ) {
-                                $cfields[ $fieldname_lowercased ] = trim( $fld, ", \n" );
+                                $cfields[ $fieldname_lowercased ] = $fld;
                         }
                 }
@@ -2244 +2329 @@
                                         if ( $do_change ) {
                                                 // Add a query to change the column type.
-                                                $cqueries[] = "ALTER TABLE {$table} CHANGE COLUMN {$tablefield->Field} " . $cfields[ $tablefield_field_lowercased ];
+                                                $cqueries[] = "ALTER TABLE {$table} CHANGE COLUMN `{$tablefield->Field}` " . $cfields[ $tablefield_field_lowercased ];
                                                 $for_update[$table.'.'.$tablefield->Field] = "Changed type of {$table}.{$tablefield->Field} from {$tablefield->Type} to {$fieldtype}";
                                         }
@@ -2254 +2339 @@
                                         if ($tablefield->Default != $default_value) {
                                                 // Add a query to change the column's default value
-                                                $cqueries[] = "ALTER TABLE {$table} ALTER COLUMN {$tablefield->Field} SET DEFAULT '{$default_value}'";
+                                                $cqueries[] = "ALTER TABLE {$table} ALTER COLUMN `{$tablefield->Field}` SET DEFAULT '{$default_value}'";
                                                 $for_update[$table.'.'.$tablefield->Field] = "Changed default value of {$table}.{$tablefield->Field} from {$tablefield->Default} to {$default_value}";
                                         }
@@ -2307 +2392 @@
                                 }
                                 $index_string .= 'KEY ';
-                                if ($index_name != 'PRIMARY') {
-                                        $index_string .= $index_name;
+                                if ( 'PRIMARY' !== $index_name  ) {
+                                        $index_string .= '`' . $index_name . '`';
                                 }
                                 $index_columns = '';
@@ -2314 +2399 @@
                                 // For each column in the index.
                                 foreach ($index_data['columns'] as $column_data) {
-                                        if ($index_columns != '') $index_columns .= ',';
+                                        if ( $index_columns != '' ) {
+                                                $index_columns .= ',';
+                                        }
 
                                         // Add the field to the column list string.
-                                        $index_columns .= $column_data['fieldname'];
+                                        $index_columns .= '`' . $column_data['fieldname'] . '`';
                                         if ($column_data['subpart'] != '') {
                                                 $index_columns .= '('.$column_data['subpart'].')';