Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.534
diff -u -F^f -r1.534 common.inc
--- includes/common.inc	12 Apr 2006 08:42:47 -0000	1.534
+++ includes/common.inc	12 Apr 2006 19:16:48 -0000
@@ -156,6 +156,43 @@ function drupal_get_headers() {
  */
 
 /**
+ * Parse an array into a valid urlencoded query string.
+ *
+ * @param $query
+ *   The array to be processed e.g. $_GET
+ * @param $exclude
+ *   The array filled with keys to be excluded. Use parent[child] to exclude nested items.
+ * @param $urlencode
+ *   If TRUE, the keys and values are both urlencoded.
+ * @param $parent
+ *   Should not be passed, only used in recursive calls
+ * @return
+ *   urlencoded string which can be appended to/as the URL query string
+ */
+function drupal_query_string_encode($query, $exclude = array(), $parent = '') {
+  $params = array();
+
+  foreach ($query as $key => $value) {
+    if ($parent) {
+      $key = $parent .'['. $key .']';
+    }
+
+    if (in_array($key, $exclude)) {
+      continue;
+    }
+
+    if (is_array($value)) {
+      $params[] = drupal_query_string_encode($value, $exclude, $key);
+    }
+    else {
+      $params[] = urlencode($key) .'='. urlencode($value);
+    }
+  }
+
+  return implode('&', $params);
+}
+
+/**
  * Prepare a destination query string for use in combination with
  * drupal_goto(). Used to direct the user back to the referring page
  * after completing a form. By default the current URL is returned.
@@ -171,17 +208,11 @@ function drupal_get_destination() {
   }
   else {
     $path = $_GET['q'];
-    $params = array();
-    foreach ($_GET as $key => $value) {
-      if ($key == 'q') {
-        continue;
-      }
-      $params[] = urlencode($key) .'='. urlencode($value);
-    }
-    if (count($params)) {
-      $path .= '?';
+    $query = drupal_query_string_encode($_GET, array('q'));
+    if ($query != '') {
+      $path .= '?'. $query;
     }
-    return 'destination='. urlencode($path . implode('&', $params));
+    return 'destination='. urlencode($path);
   }
 }
 
Index: includes/pager.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/pager.inc,v
retrieving revision 1.53
diff -u -F^f -r1.53 pager.inc
--- includes/pager.inc	15 Jan 2006 16:55:35 -0000	1.53
+++ includes/pager.inc	12 Apr 2006 19:16:49 -0000
@@ -49,7 +49,7 @@
  * @ingroup database
  */
 function pager_query($query, $limit = 10, $element = 0, $count_query = NULL) {
-  global $pager_page_array, $pager_total, $pager_total_items;
+  global $pager_page_array, $pager_total, $pager_total_items, $pager_url_query;
   $page = isset($_GET['page']) ? $_GET['page'] : '';
 
   // Substitute in query arguments.
@@ -68,6 +68,9 @@ function pager_query($query, $limit = 10
   // Convert comma-separated $page to an array, used by other functions.
   $pager_page_array = explode(',', $page);
 
+  // Generate the query to be appended to l()
+  $pager_url_query[$element] = drupal_query_string_encode($_GET, array('q', 'page'));
+
   // We calculate the total of pages as ceil(items / limit).
   if (count($args)) {
     $pager_total_items[$element] = db_result(db_query($count_query, $args));
@@ -179,6 +182,7 @@ function theme_pager_previous($text, $li
   // If we are anywhere but the first page
   if ($pager_page_array[$element] > 0) {
     $page_new = pager_load_array($pager_page_array[$element] - $interval, $element, $pager_page_array);
+
     // If the previous page is the first page, mark the link as such.
     if ($page_new[$element] == 0) {
       $output = theme('pager_first', $text, $limit, $element, $parameters);
@@ -351,14 +355,18 @@ function theme_pager_list($limit, $eleme
  *   An HTML string that generates the link.
  */
 function theme_pager_link($text, $page_new, $element, $parameters = array(), $attributes = array()) {
+  global $pager_url_query;
+
   $page = isset($_GET['page']) ? $_GET['page'] : '';
   if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {
     $parameters['page'] = $new_page;
   }
 
   $query = array();
-  foreach ($parameters as $key => $value) {
-    $query[] = $key .'='. $value;
+  $query[] = drupal_query_string_encode($parameters, array());
+
+  if ($pager_url_query[$element] != '') {
+    $query[] = $pager_url_query[$element];
   }
 
   // Set each pager link title
Index: includes/tablesort.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/tablesort.inc,v
retrieving revision 1.37
diff -u -F^f -r1.37 tablesort.inc
--- includes/tablesort.inc	10 Dec 2005 19:26:47 -0000	1.37
+++ includes/tablesort.inc	12 Apr 2006 19:16:50 -0000
@@ -135,13 +135,13 @@ function tablesort_cell($cell, $header, 
  */
 function tablesort_get_querystring() {
   $cgi = $_SERVER['REQUEST_METHOD'] == 'GET' ? $_GET : $_POST;
-  $query_string = '';
-  foreach ($cgi as $key => $val) {
-    if ($key != 'order' && $key != 'sort' && $key != 'q') {
-      $query_string .= '&'. $key .'='. $val;
-    }
+  $query_string = drupal_query_string_encode($cgi, array('q', 'order', 'sort'));
+
+  if ($query_string != '') {
+    return '&'. $query_string;
   }
-  return $query_string;
+
+  return '';
 }
 
 /**