Bug fix: don't allow users to be inserted in several groups

admin/uploaduser.php

@@ -209,8 +209,9 @@
                 for ($i=0; $i<5; $i++) {
 		  if ($courseid[$i] && $groupid[$i]) {
 		    if (record_exists("user_students","userid",$user->id,"course",$courseid[$i])) {
-		      if (record_exists("groups_members","groupid",$groupid[$i],"userid",$user->id)) {
-			notify('-->' . get_string('addedtogroup','',$addgroup[$i]));
+		      $usergroup = user_group($courseid[$i],$user->id);
+                      if ($usergroup) {
+			notify('-->' . get_string('groupalready','error',$usergroup->name));
 		      } else {
 			$group_member->groupid = $groupid[$i];
 			$group_member->userid = $user->id;

lang/en/error.php

@@ -4,6 +4,7 @@
 $string['coursegroupunknown'] = 'Course corresponding to group $a not specified';
 $string['erroronline'] = 'Error on line $a';
 $string['fieldrequired'] = '\"$a\" is a required field';
+$string['groupalready'] = 'User already belongs to group $a';
 $string['groupunknown'] = 'Group $a not associated to specified course';
 $string['invalidfieldname'] = '\"$a\" is not a valid field name';
 $string['missingfield'] = 'Field \"$a\" is missing';