Add timeline issue access check + reduce queries

- Add access level that issues are visible now that we work directly on history rows.
- Only retrieve the N required rows for the default view, some of the N may be filtered later, causing the view to have less than N entries.

core/history_api.php

@@ -184,10 +184,15 @@ function history_count_user_recent_events( $p_duration_in_seconds, $p_user_id =
  * @param integer $p_user_id A valid user identifier.
  * @param integer $p_start_time The start time to filter by, or null for all.
  * @param integer $p_end_time   The end time to filter by, or null for all.
+ * @param integer $p_max_events The maximum number of events to return or null/0 for all.
  * @return array
  */
-function history_get_raw_events_array( $p_bug_id, $p_user_id = null, $p_start_time = null, $p_end_time = null ) {
-	$t_history_order = config_get( 'history_order' );
+function history_get_raw_events_array( $p_bug_id, $p_user_id = null, $p_start_time = null, $p_end_time = null, $p_max_events = null, $p_sort_order = null ) {
+	if ( $p_sort_order === null ) {
+		$t_history_order = config_get( 'history_order' );
+	} else {
+		$t_history_order = $p_sort_order;
+	}
 
 	$t_user_id = (( null === $p_user_id ) ? auth_get_current_user_id() : $p_user_id );
 
@@ -339,6 +344,10 @@ function history_get_raw_events_array( $p_bug_id, $p_user_id = null, $p_start_ti
 		$t_raw_history[$j]['new_value'] = $v_new_value;
 
 		$j++;
+
+		if ( $p_max_events !== null && $p_max_events !== 0 && $j >= $p_max_events ) {
+			break;
+		}
 	}
 
 	# end for loop

core/timeline_api.php

@@ -42,8 +42,7 @@
 function timeline_events( $p_start_time, $p_end_time, $p_max_events ) {
 	$t_timeline_events = array();
 
-		$t_history_events_array = history_get_raw_events_array( null, null, $p_start_time, $p_end_time );
-		$t_history_events_array = array_reverse( $t_history_events_array );
+		$t_history_events_array = history_get_raw_events_array( null, null, $p_start_time, $p_end_time, $p_max_events, 'DESC' );
 		$t_count = 0;
 
 		foreach ( $t_history_events_array as $t_history_event ) {

core/timeline_inc.php

@@ -46,10 +46,8 @@
 
 timeline_print_events( $t_events );
 
-# Don't display "More Events" link if there are no more entries to show
-# Note: as of 2015-01-19, this does not cover the case of entries excluded
-# by filtering (e.g. Status Change not in RESOLVED, CLOSED, REOPENED)
-if( !$f_all && count( $t_events ) == $t_max_events ) {
+# We will compromise accuracy of more link and showing exactly N without clicking more in favor or reducing load.
+if( !$f_all ) {
 	echo '<p>' . $t_prev_link = ' [ <a href="my_view_page.php?days=' . $f_days . '&amp;all=1">' . lang_get( 'timeline_more' ) . '</a> ]</p>';
 }