Clear checkbox selections when form is processed

functions/html.php

@@ -359,15 +359,20 @@ function set_uri_vars($uri, $values, $sanitize=TRUE) {
  *
  * @param string $url url that must be modified
  * @param string $var GET variable name
- * @param string $val variable value
+ * @param string $val variable value (CANNOT be an array)
  * @param boolean $link controls sanitizing of ampersand in urls (since 1.3.2)
+ * @param boolean $treat_as_array When TRUE, if $var is an array (it occurs one
+ *                                or more times with square brackets after it,
+ *                                e.g. "var[1]"), the whole array will be removed
+ *                                (when $val is NULL) or the given value will be
+ *                                added to the next array slot (@since 1.4.23/1.5.2)
  *
  * @return string $url modified url
  *
  * @since 1.3.0
  *
  */
-function set_url_var($url, $var, $val=null, $link=true) {
+function set_url_var($url, $var, $val=null, $link=true, $treat_as_array=false) {
     $url = str_replace('&','&',$url);
 
     if (strpos($url, '?') === false) {
@@ -378,18 +383,35 @@ function set_url_var($url, $var, $val=null, $link=true) {
         
     $newpar = array(); 
     $params = explode('&', $params);
+    $array_names = array();
    
     foreach ($params as $p) {
         if (trim($p)) {
             $p = explode('=', $p);
             $newpar[$p[0]] = (isset($p[1]) ? $p[1] : '');
+            if ($treat_as_array && preg_match('/(.*)\[(\d+)]$/', $p[0], $matches)) {
+               if (!is_array($array_names[$matches[1]])) $array_names[$matches[1]] = array();
+               $array_names[$matches[1]][$matches[2]] = $p[1];
+            }
         }
     }
 
     if (is_null($val)) {
-        unset($newpar[$var]);
+        if ($treat_as_array && !empty($array_names[$var])) {
+            foreach ($array_names[$var] as $key => $ignore)
+                unset($newpar[$var . '[' . $key . ']']);
+        } else {
+            unset($newpar[$var]);
+        }
     } else {
-        $newpar[$var] = $val;
+        if ($treat_as_array && !empty($array_names[$var])) {
+            $max_key = 0;
+            foreach ($array_names[$var] as $key => $ignore)
+                if ($key >= $max_key) $max_key = $key + 1;
+            $newpar[$var . '[' . $max_key . ']'] = $val;
+        } else {
+            $newpar[$var] = $val;
+        }
     }
 
     if (!count($newpar)) {

src/right_main.php

@@ -236,6 +236,8 @@ if (!sqgetGlobalVar('align',$align,SQ_SESSION)) {
 $sError = handleMessageListForm($imapConnection,$aMailbox);
 if ($sError) {
    $note = $sError;
+} else if (sqgetGlobalVar('REQUEST_METHOD', $req_method, SQ_SERVER) && $req_method == 'POST') {
+   $preselected = array(); // clear pre-checked checkboxes when action succeeded
 }