Call db_query_bound() with array() instead of null

This is not strictly necessary right now, but replacing known occurences
avoids future refactoring should we decide to change the default value
for $p_arr_parms to array() later on.

core/project_hierarchy_api.php

@@ -172,7 +172,7 @@ function project_hierarchy_cache( $p_show_disabled = false ) {
 				  WHERE $t_enabled_clause
 				  ORDER BY p.name";
 
-	$t_result = db_query_bound( $t_query, ( $p_show_disabled ? null : array( true ) ) );
+	$t_result = db_query_bound( $t_query, ( $p_show_disabled ? array() : array( true ) ) );
 
 	$g_cache_project_hierarchy = array();
 	$g_cache_project_inheritance = array();

core/summary_api.php

@@ -569,7 +569,7 @@ function summary_print_by_reporter() {
 				WHERE $t_specific_where
 				GROUP BY reporter_id
 				ORDER BY num DESC";
-	$t_result = db_query_bound( $t_query, null, $t_reporter_summary_limit );
+	$t_result = db_query_bound( $t_query, array(), $t_reporter_summary_limit );
 
 	$t_reporters = array();
 	while( $t_row = db_fetch_array( $t_result ) ) {

core/user_api.php

@@ -1074,7 +1074,7 @@ function user_get_accessible_subprojects( $p_user_id, $p_project_id, $p_show_dis
 					  WHERE $t_enabled_clause
 					  	 ph.parent_id IS NOT NULL
 					  ORDER BY p.name";
-		$t_result = db_query_bound( $t_query, ( $p_show_disabled ? null : array( true ) ) );
+		$t_result = db_query_bound( $t_query, ( $p_show_disabled ? array() : array( true ) ) );
 	} else {
 		$t_query = "SELECT DISTINCT p.id, p.name, ph.parent_id
 					  FROM $t_project_table p

manage_user_page.php

@@ -179,7 +179,7 @@
 echo '</ul>';
 echo '</div>';
 
-$t_where_params = null;
+$t_where_params = array();
 if( $f_filter === 'ALL' ) {
 	$t_where = '(1 = 1)';
 } else if( $f_filter === 'UNUSED' ) {