Various changes to feed.php’s parameter handling

  * Do not emit E_NOTICEs
  * Introduce explicit feed mode default value »recent« instead of handling
    every unknown feed mode as recent changes mode. This means:
    - FEED_MODE_UNKNOWN is only executed if the given feed mode is indeed
      unknown. This is specifically not the case if no feed mode request param
      has been specified or the requested feed mode is »recent«.
    - FEED_MODE_UNKNOWN dies with an error as default behaviour
  * opt[items] is forced to be a non-negative integer
  * opt[show_minor] is forced to be a boolean and thus has a default value of
    false instead of null

1 files changed, 49 insertions, 23 deletions

diff --git a/feed.php b/feed.php
index 9536c9986..615d1597d 100644
--- a/feed.php
+++ b/feed.php
@@ -24,7 +24,7 @@ $cache = new cache($key, '.feed');
 // prepare cache depends
 $depends['files'] = getConfigFiles('main');
 $depends['age']   = $conf['rss_update'];
-$depends['purge'] = ($_REQUEST['purge']) ? true : false;
+$depends['purge'] = isset($_REQUEST['purge']);
 
 // check cacheage and deliver if nothing has changed since last
 // time or the update interval has not passed, also handles conditional requests
@@ -55,18 +55,20 @@ $image->link = DOKU_URL;
 $rss->image = $image;
 
 $data = null;
-if($opt['feed_mode'] == 'list'){
-    $data = rssListNamespace($opt);
-}elseif($opt['feed_mode'] == 'search'){
-    $data = rssSearch($opt);
-}else{
+$modes = array('list'   => 'rssListNamespace',
+               'search' => 'rssSearch',
+               'recent' => 'rssRecentChanges');
+if (isset($modes[$opt['feed_mode']])) {
+    $data = $modes[$opt['feed_mode']]($opt);
+} else {
     $eventData = array(
         'opt'  => &$opt,
         'data' => &$data,
     );
     $event = new Doku_Event('FEED_MODE_UNKNOWN', $eventData);
     if ($event->advise_before(true)) {
-        $data = rssRecentChanges($opt);
+        echo sprintf('<error>Unknown feed mode %s</error>', hsc($opt['feed_mode']));
+        exit;
     }
     $event->advise_after();
 }
@@ -83,29 +85,53 @@ print $feed;
 // ---------------------------------------------------------------- //
 
 /**
- * Get URL parameters and config options and return a initialized option array
+ * Get URL parameters and config options and return an initialized option array
  *
  * @author Andreas Gohr <andi@splitbrain.org>
  */
 function rss_parseOptions(){
     global $conf;
 
-    $opt['items']        = (int) $_REQUEST['num'];
-    $opt['feed_type']    = $_REQUEST['type'];
-    $opt['feed_mode']    = $_REQUEST['mode'];
-    $opt['show_minor']   = $_REQUEST['minor'];
-    $opt['namespace']    = $_REQUEST['ns'];
-    $opt['link_to']      = $_REQUEST['linkto'];
-    $opt['item_content'] = $_REQUEST['content'];
-    $opt['search_query'] = $_REQUEST['q'];
-
-    if(!$opt['feed_type'])    $opt['feed_type']    = $conf['rss_type'];
-    if(!$opt['item_content']) $opt['item_content'] = $conf['rss_content'];
-    if(!$opt['link_to'])      $opt['link_to']      = $conf['rss_linkto'];
-    if(!$opt['items'])        $opt['items']        = $conf['recent'];
+    $opt = array();
+
+    foreach(array(
+                  // Basic feed properties
+                  // Plugins may probably want to add new values to these
+                  // properties for implementing own feeds
+
+                  // One of: list, search, recent
+                  'feed_mode'    => array('mode', 'recent'),
+                  // One of: diff, page, rev, current
+                  'link_to'      => array('linkto', $conf['rss_linkto']),
+                  // One of: abstract, diff, htmldiff, html
+                  'item_content' => array('content', $conf['rss_content']),
+
+                  // Special feed properties
+                  // These are only used by certain feed_modes
+
+                  // String, used for feed title, in list and rc mode
+                  'namespace'    => array('ns', null),
+                  // Positive integer, only used in rc mode
+                  'items'        => array('num', $conf['recent']),
+                  // Boolean, only used in rc mode
+                  'show_minor'   => array('minor', false),
+                  // String, only used in search mode
+                  'search_query' => array('q', null),
+
+                 ) as $name => $val) {
+        $opt[$name] = (isset($_REQUEST[$val[0]]) && !empty($_REQUEST[$val[0]]))
+                      ? $_REQUEST[$val[0]] : $val[1];
+    }
+
+    $opt['items']        = max(0, (int)  $opt['items']);
+    $opt['show_minor']   = (bool) $opt['show_minor'];
+
     $opt['guardmail']  = ($conf['mailguard'] != '' && $conf['mailguard'] != 'none');
 
-    switch ($opt['feed_type']){
+    $type = valid_input_set('type', array('rss','rss2','atom','atom1','rss1',
+                                          'default' => $conf['rss_type']),
+                            $_REQUEST);
+    switch ($type){
         case 'rss':
             $opt['feed_type'] = 'RSS0.91';
             $opt['mime_type'] = 'text/xml';
@@ -279,7 +305,7 @@ function rss_buildItems(&$rss,&$data,$opt){
             }
 
             // add category
-            if($meta['subject']){
+            if(isset($meta['subject'])) {
                 $item->category = $meta['subject'];
             }else{
                 $cat = getNS($id);