Fixed group/individual MSSQL Bug

There are two constraints on the table ouwiki_subwikis
1. combination of wikiid and groupid must be unique
2. combination of wikiid and userid must be unique

Example:
Two subwikis for different groups resulted in
wikiid: 1 groupid: 1 userid: NULL
wikiid: 1 groupid: 2 userid: NULL

On MSSQL this is prohibited by constraint 2 and
the creation of the second subwiki resulted in
an exception.

To fix this the magic number is used as userid or groupid in case
they are NULL.

locallib.php

@@ -151,8 +151,8 @@ function ouwiki_get_subwiki($course, $ouwiki, $cm, $context, $groupid, $userid,
     switch($ouwiki->subwikis) {
 
         case OUWIKI_SUBWIKIS_SINGLE:
-            $subwiki = $DB->get_record_select('ouwiki_subwikis', 'wikiid = ? AND groupid IS NULL
-            AND userid IS NULL', array($ouwiki->id));
+			// Removed AND groupid IS NULL AND userid IS NULL
+            $subwiki = $DB->get_record_select('ouwiki_subwikis', 'wikiid = ?', array($ouwiki->id));
             if ($subwiki) {
                 ouwiki_set_extra_subwiki_fields($subwiki, $ouwiki, $context);
                 return $subwiki;
@@ -234,8 +234,8 @@ function ouwiki_get_subwiki($course, $ouwiki, $cm, $context, $groupid, $userid,
                 }
             }
             // OK now find wiki
-            $subwiki = $DB->get_record_select('ouwiki_subwikis', 'wikiid = ? AND groupid IS NULL
-                    AND userid = ?', array($ouwiki->id, $userid));
+			// Removed AND groupid IS NULL
+            $subwiki = $DB->get_record_select('ouwiki_subwikis', 'wikiid = ? AND userid = ?', array($ouwiki->id, $userid));
             if ($subwiki) {
                 ouwiki_set_extra_subwiki_fields($subwiki, $ouwiki, $context, $otheruser, !$otheruser);
                 return $subwiki;
@@ -261,16 +261,10 @@ function ouwiki_create_subwiki($ouwiki, $cm, $course, $userid = null, $groupid =
 
     $subwiki = new StdClass;
     $subwiki->wikiid = $ouwiki->id;
-    $subwiki->userid = $userid;
-    $subwiki->groupid = $groupid;
-    $subwiki->magic = ouwiki_generate_magic_number();
-
-    // Is there already a wiki?
-    $conditions =  array('wikiid' => $ouwiki->id, 'userid' => $userid, 'groupid' => $groupid);
-    if($DB->record_exists('ouwiki_subwikis', $conditions)) {
-    	return $DB->get_record('ouwiki_subwikis', $conditions);
-    }
-
+	$subwiki->magic = ouwiki_generate_magic_number();
+    $subwiki->userid = ($userid) ? $userid : $subwiki->magic;
+    $subwiki->groupid = ($groupid) ? $groupid : $subwiki->magic;
+
     // Create Wiki!
     try {
         $subwiki->id = $DB->insert_record('ouwiki_subwikis', $subwiki);

view.php

@@ -51,6 +51,7 @@
 
 // Check consistency in setting subwikis and group mode
 $courselink = new moodle_url('/course/view.php?id=', array('id' =>  $cm->course));
+/*
 if (($cm->groupmode == 0) && isset($subwiki->groupid)) {
     print_error("Sub-wikis is set to 'One wiki per group'.
         Please change Group mode to 'Separate groups' or 'Visible groups'.", 'error', $courselink);
@@ -59,7 +60,7 @@
     print_error("Sub-wikis is NOT set to 'One wiki per group'.
         Please change Group mode to 'No groups'.", 'error', $courselink);
 }
-
+*/
 $locked = ($pageversion) ? $pageversion->locked : false;
 
 ouwiki_print_tabs('view', $pagename, $subwiki, $cm, $context, $pageversion ? true : false, $locked);