NOBUG: partially re-introduce DB object static cache, as we need to avoid dupes

when two indexes are created in the same sentence and initials are the same (contenthash, contextid)
This introduces some problems in Oracle but... better to keep the rest working.

diff --git a/lib/ddl/sql_generator.php b/lib/ddl/sql_generator.php
index 810eba2..f54b728 100644 (file)
--- a/lib/ddl/sql_generator.php
+++ b/lib/ddl/sql_generator.php
@@ -947,6 +947,12 @@ abstract class sql_generator {
 
         $name = '';
 
+    /// Implement one basic cache to avoid object name duplication
+    /// along all the request life, but never to return cached results
+        if (!isset($used_names)) {
+            static $used_names = array();
+        }
+
     /// Use standard naming. See http://docs.moodle.org/en/XMLDB_key_and_index_naming
         $tablearr = explode ('_', $tablename);
         foreach ($tablearr as $table) {
@@ -969,7 +975,7 @@ abstract class sql_generator {
         }
 
     /// If the calculated name is in the cache, or if we detect it by introspecting the DB let's modify if
-        if ($this->isNameInUse($namewithsuffix, $suffix, $tablename)) {
+        if (in_array($namewithsuffix, $used_names) || $this->isNameInUse($namewithsuffix, $suffix, $tablename)) {
             $counter = 2;
         /// If have free space, we add 2
             if (strlen($namewithsuffix) < $this->names_max_length) {
@@ -983,7 +989,7 @@ abstract class sql_generator {
                 $newnamewithsuffix = $newnamewithsuffix . '_' . $suffix;
             }
         /// Now iterate until not used name is found, incrementing the counter
-            while ($this->isNameInUse($newnamewithsuffix, $suffix, $tablename)) {
+            while (in_array($newnamewithsuffix, $used_names) || $this->isNameInUse($newnamewithsuffix, $suffix, $tablename)) {
                 $counter++;
                 $newname = substr($name, 0, strlen($newname)-1) . $counter;
                 $newnamewithsuffix = $newname;
@@ -994,6 +1000,9 @@ abstract class sql_generator {
             $namewithsuffix = $newnamewithsuffix;
         }
 
+    /// Add the name to the cache
+        $used_names[$tablename.'-'.$fields.'-'.$suffix] = $namewithsuffix;
+
     /// Quote it if necessary (reserved words)
         $namewithsuffix = $this->getEncQuoted($namewithsuffix);