Ticket #10404: 10404.patch_caseinsensitive_and_noindexname_compare

Index: upgrade.php
===================================================================
--- upgrade.php (revision 26316)
+++ upgrade.php (working copy)
@@ -1501,15 +1501,21 @@
 }
 
 /**
- * {@internal Missing Short Description}}
+ * Create or update database tables based on analyis of SQL queries provided.
  *
- * {@internal Missing Long Description}}
+ * Adding indices to tables should be in the form:
+ * KEY <keyname> (<field list>)
  *
+ * Key name should be provided for all key types but is REQUIRED for compound keys such as KEY mycompoundkey (id,flda).
+ *
+ * Failure to create table indices with the proper syntax can produce duplicate keys which degrades performance during
+ * record inserts and updates for the affected table.
+ *
  * @since 1.5.0
  *
- * @param unknown_type $queries
- * @param unknown_type $execute
- * @return unknown
+ * @param string[] $queries single string or array of strings representing SQL queries
+ * @param boolean $execute
+ * @return string[]
  */
 function dbDelta( $queries = '', $execute = true ) {
        global $wpdb;
@@ -1577,7 +1583,11 @@
                        preg_match("|^([^ ]*)|", trim($fld), $fvals);
                        $fieldname = trim( $fvals[1], '`' );
 
-                       // Verify the found field name
+                       // Verify the found field name,
+            //
+            // Field names do NOT have index commands on the query line.
+            // Put those lines into the indices array for later inspection.
+            //
                        $validfield = true;
                        switch (strtolower($fieldname)) {
                        case '':
@@ -1587,7 +1597,7 @@
                        case 'unique':
                        case 'key':
                                $validfield = false;
-                               $indices[] = trim(trim($fld), ", \n");
+                               $indices[] = strtoupper(trim(trim($fld), ", \n"));
                                break;
                        }
                        $fld = trim($fld);
@@ -1655,20 +1665,38 @@
                        }
 
                        // For each actual index in the index array
+            // Build a create string to compare to the query
+            //
                        foreach ($index_ary as $index_name => $index_data) {
-                               // Build a create string to compare to the query
+                       
+                // Initialize the string
                                $index_string = '';
+
+                // Special Operator: PRIMARY
+                //
                                if ($index_name == 'PRIMARY') {
                                        $index_string .= 'PRIMARY ';
+
+                // Special Operator UNIQUE
+                //
                                } else if($index_data['unique']) {
                                        $index_string .= 'UNIQUE ';
                                }
+
+                // All indices utilize the KEY operator
+                //
                                $index_string .= 'KEY ';
+
+                // Add the index name for all index types EXCEPT the PRIMARY index
+                //
                                if ($index_name != 'PRIMARY') {
                                        $index_string .= $index_name;
                                }
+
+                               // For each column in the index
+                // Build the column definition (the part inside the parens)
+                //
                                $index_columns = '';
-                               // For each column in the index
                                foreach ($index_data['columns'] as $column_data) {
                                        if ($index_columns != '') $index_columns .= ',';
                                        // Add the field to the column list string
@@ -1677,17 +1705,47 @@
                                                $index_columns .= '('.$column_data['subpart'].')';
                                        }
                                }
+
                                // Add the column list to the index create string
                                $index_string .= ' ('.$index_columns.')';
-                               if (!(($aindex = array_search($index_string, $indices)) === false)) {
+
+                // Now go look to see if the index string we just built from the table meta data
+                // matches any of the index build strings the user specified in the create table SQL
+                // and REMOVE any that match from the "indices to be created" stack
+                //
+                // Start with the WP3.7.1 (and earlier) index string with the index name specified
+                // KEY id (id)
+                //
+                               if (!(($aindex = array_search(strtoupper($index_string), $indices)) === false)) {
                                        unset($indices[$aindex]);
-                                       //echo "<pre style=\"border:1px solid #ccc;margin-top:5px;\">{$table}:<br />Found index:".$index_string."</pre>\n";
-                               }
-                               //else echo "<pre style=\"border:1px solid #ccc;margin-top:5px;\">{$table}:<br /><b>Did not find index:</b>".$index_string."<br />".print_r($indices, true)."</pre>\n";
+
+                // Check for a version where the optional index name was not specified (default to single column name)
+                // KEY (id)
+                //
+                // Convert the string we are trying to match from KEY <fldname> (<fldname>) to KEY (<fldname>)
+                //
+                // Make sure the pattern matches KEY <something> (<something>) and
+                // that the first <something> is identical to the second <something>
+                //
+                // If it does, strip out the first <something>\s+, then re-check for an index match.
+                //
+                               } else {
+                    if (
+                        ( preg_match('/(KEY\s+)(\w+)\s+(\((\w+)\))/',$index_string,$regex_matches) === 1 ) &&
+                        ( $regex_matches[2] === $regex_matches[4] )
+                        ) {
+                        $index_string = $regex_matches[1].$regex_matches[3];
+                        if (!(($aindex = array_search(strtoupper($index_string), $indices)) === false)) {
+                            unset($indices[$aindex]);
+                        }
+                    }
+                }
+
                        }
                }
 
-               // For every remaining index specified for the table
+        // Add the indices to the table.
+        //
                foreach ( (array) $indices as $index ) {
                        // Push a query line into $cqueries that adds the index to that table
                        $cqueries[] = "ALTER TABLE {$table} ADD $index";