Have get_arg never return null

90% of places assume it will never return null, and they will break in
weird ways if it does return null

core/event.php

@@ -106,13 +106,28 @@ class PageRequestEvent extends Event
     /**
      * Get the n th argument of the page request (if it exists.)
      */
-    public function get_arg(int $n): ?string
+    public function get_arg(int $n): string
     {
         $offset = $this->part_count + $n;
         if ($offset >= 0 && $offset < $this->arg_count) {
             return $this->args[$offset];
         } else {
-            return null;
+            throw new SCoreException("Requested an invalid argument #$n");
+        }
+    }
+
+    public function try_page_num(int $n): int {
+        if($this->count_args() > $n) {
+            $i = $this->get_arg($n);
+            if (!is_numeric($i) || $i <= 0) {
+                return int_escape($i);
+            }
+            else {
+                return 1;
+            }
+        }
+        else {
+            return 1;
         }
     }
 

ext/alias_editor/main.php

@@ -49,13 +49,18 @@ class AliasEditor extends Extension
                     }
                 }
             } elseif ($event->get_arg(0) == "list") {
-                $page_number = $event->get_arg(1);
+                if($event->count_args() == 2) {
-                if (is_null($page_number) || !is_numeric($page_number)) {
+                    $page_number = $event->get_arg(1);
+                    if (!is_numeric($page_number)) {
+                        $page_number = 0;
+                    } elseif ($page_number <= 0) {
+                        $page_number = 0;
+                    } else {
+                        $page_number--;
+                    }
+                }
+                else {
                     $page_number = 0;
-                } elseif ($page_number <= 0) {
-                    $page_number = 0;
-                } else {
-                    $page_number--;
                 }
 
                 $alias_per_page = $config->get_int('alias_items_per_page', 30);

ext/arrowkey_navigation/main.php

@@ -54,21 +54,23 @@ class ArrowkeyNavigation extends Extension
         // get the amount of images per page
         $images_per_page = $config->get_int(IndexConfig::IMAGES);
 
-        // if there are no tags, use default
+		if($event->count_args() > 1) {
-        if (is_null($event->get_arg(1))) {
+			// if there are tags, use pages with tags
-            $prefix = "";
-            $page_number = int_escape($event->get_arg(0));
-            $total_pages = ceil($database->get_one(
-                "SELECT COUNT(*) FROM images"
-            ) / $images_per_page);
-        } else { // if there are tags, use pages with tags
             $prefix = url_escape($event->get_arg(0)) . "/";
-            $page_number = int_escape($event->get_arg(1));
+            $page_number = $event->try_page_num(1);
             $total_pages = ceil($database->get_one(
                 "SELECT count FROM tags WHERE tag=:tag",
                 ["tag"=>$event->get_arg(0)]
             ) / $images_per_page);
         }
+        else {
+			// if there are no tags, use default
+            $prefix = "";
+            $page_number = $event->try_page_num(0);
+            $total_pages = ceil($database->get_one(
+                "SELECT COUNT(*) FROM images"
+            ) / $images_per_page);
+        }
 
         // creates previous & next values
         // When previous first page, go to last page

ext/blotter/main.php

@@ -71,7 +71,7 @@ class Blotter extends Extension
     public function onPageRequest(PageRequestEvent $event)
     {
         global $page, $database, $user;
-        if ($event->page_matches("blotter")) {
+        if ($event->page_matches("blotter") && $event->count_args() > 0) {
             switch ($event->get_arg(0)) {
                 case "editor":
                     /**

ext/comment/main.php

@@ -243,14 +243,14 @@ class CommentList extends Extension
 
     private function onPageRequest_list(PageRequestEvent $event)
     {
-        $page_num = int_escape($event->get_arg(1));
+        $page_num = $event->try_page_num(1);
         $this->build_page($page_num);
     }
 
     private function onPageRequest_beta_search(PageRequestEvent $event)
     {
         $search = $event->get_arg(1);
-        $page_num = int_escape($event->get_arg(2));
+		$page_num = $event->try_page_num(2);
         $duser = User::by_name($search);
         $i_comment_count = Comment::count_comments_by_user($duser);
         $com_per_page = 50;

ext/cron_uploader/main.php

@@ -36,9 +36,8 @@ class CronUploader extends Extension
         global $user;
 
         if ($event->page_matches("cron_upload")) {
-            $key = $event->get_arg(0);
+            if ($event->count_args() == 1) {
-            if (!empty($key)) {
+                $this->process_upload($event->get_arg(0)); // Start upload
-                $this->process_upload($key); // Start upload
             } elseif ($user->can(Permissions::CRON_ADMIN)) {
                 $this->display_documentation();
             }

ext/danbooru_api/main.php

@@ -4,37 +4,31 @@ class DanbooruApi extends Extension
 {
     public function onPageRequest(PageRequestEvent $event)
     {
-        if ($event->page_matches("api") && ($event->get_arg(0) == 'danbooru')) {
+        if ($event->page_matches("api/danbooru")) {
-            $this->api_danbooru($event);
+            global $page;
-        }
+            $page->set_mode(PageMode::DATA);
-    }
 
-    // Danbooru API
+            if ($event->page_matches("api/danbooru/add_post") || $event->page_matches("api/danbooru/post/create.xml")) {
-    private function api_danbooru(PageRequestEvent $event)
+                // No XML data is returned from this function
-    {
+                $page->set_type("text/plain");
-        global $page;
+                $this->api_add_post();
-        $page->set_mode(PageMode::DATA);
+            } elseif ($event->page_matches("api/danbooru/find_posts") || $event->page_matches("api/danbooru/post/index.xml")) {
+                $page->set_type("application/xml");
+                $page->set_data($this->api_find_posts());
+            } elseif ($event->page_matches("api/danbooru/find_tags")) {
+                $page->set_type("application/xml");
+                $page->set_data($this->api_find_tags());
+            }
 
-        if (($event->get_arg(1) == 'add_post') || (($event->get_arg(1) == 'post') && ($event->get_arg(2) == 'create.xml'))) {
+            // Hackery for danbooruup 0.3.2 providing the wrong view url. This simply redirects to the proper
-            // No XML data is returned from this function
+            // Shimmie view page
-            $page->set_type("text/plain");
+            // Example: danbooruup says the url is http://shimmie/api/danbooru/post/show/123
-            $this->api_add_post();
+            // This redirects that to http://shimmie/post/view/123
-        } elseif (($event->get_arg(1) == 'find_posts') || (($event->get_arg(1) == 'post') && ($event->get_arg(2) == 'index.xml'))) {
+            elseif ($event->page_matches("api/danbooru/post/show")) {
-            $page->set_type("application/xml");
+                $fixedlocation = make_link("post/view/" . $event->get_arg(0));
-            $page->set_data($this->api_find_posts());
+                $page->set_mode(PageMode::REDIRECT);
-        } elseif ($event->get_arg(1) == 'find_tags') {
+                $page->set_redirect($fixedlocation);
-            $page->set_type("application/xml");
+            }
-            $page->set_data($this->api_find_tags());
-        }
-
-        // Hackery for danbooruup 0.3.2 providing the wrong view url. This simply redirects to the proper
-        // Shimmie view page
-        // Example: danbooruup says the url is http://shimmie/api/danbooru/post/show/123
-        // This redirects that to http://shimmie/post/view/123
-        elseif (($event->get_arg(1) == 'post') && ($event->get_arg(2) == 'show')) {
-            $fixedlocation = make_link("post/view/" . $event->get_arg(3));
-            $page->set_mode(PageMode::REDIRECT);
-            $page->set_redirect($fixedlocation);
         }
     }
 

ext/ext_manager/main.php

@@ -38,7 +38,7 @@ class ExtManager extends Extension
         global $page, $user;
         if ($event->page_matches("ext_manager")) {
             if ($user->can(Permissions::MANAGE_EXTENSION_LIST)) {
-                if ($event->get_arg(0) == "set" && $user->check_auth_token()) {
+                if ($event->count_args() == 1 && $event->get_arg(0) == "set" && $user->check_auth_token()) {
                     if (is_writable("data/config")) {
                         $this->set_things($_POST);
                         log_warning("ext_manager", "Active extensions changed", "Active extensions changed");
@@ -60,11 +60,14 @@ class ExtManager extends Extension
         }
 
         if ($event->page_matches("ext_doc")) {
-            $ext = $event->get_arg(0);
+            if($event->count_args() == 1) {
-            if (file_exists("ext/$ext/info.php")) {
+                $ext = $event->get_arg(0);
-                $info = ExtensionInfo::get_by_key($ext);
+                if (file_exists("ext/$ext/info.php")) {
-                $this->theme->display_doc($page, $info);
+                    $info = ExtensionInfo::get_by_key($ext);
-            } else {
+                    $this->theme->display_doc($page, $info);
+                }
+            }
+            else {
                 $this->theme->display_table($page, $this->get_extensions(false), false);
             }
         }

ext/forum/main.php

@@ -245,18 +245,23 @@ class Forum extends Extension
     private function show_last_threads(Page $page, PageRequestEvent $event, $showAdminOptions = false)
     {
         global $config, $database;
-        $pageNumber = $event->get_arg(1);
         $threadsPerPage = $config->get_int('forumThreadsPerPage', 15);
         $totalPages = ceil($database->get_one("SELECT COUNT(*) FROM forum_threads") / $threadsPerPage);
 
-        if (is_null($pageNumber) || !is_numeric($pageNumber)) {
+        if($event->count_args() >= 2) {
+            $pageNumber = $event->get_arg(1);
+            if (!is_numeric($pageNumber)) {
+                $pageNumber = 0;
+            } elseif ($pageNumber <= 0) {
+                $pageNumber = 0;
+            } elseif ($pageNumber >= $totalPages) {
+                $pageNumber = $totalPages - 1;
+            } else {
+                $pageNumber--;
+            }
+        }
+        else {
             $pageNumber = 0;
-        } elseif ($pageNumber <= 0) {
-            $pageNumber = 0;
-        } elseif ($pageNumber >= $totalPages) {
-            $pageNumber = $totalPages - 1;
-        } else {
-            $pageNumber--;
         }
 
         $threads = $database->get_all(
@@ -278,19 +283,24 @@ class Forum extends Extension
     {
         global $config, $database;
         $threadID = $event->get_arg(1);
-        $pageNumber = $event->get_arg(2);
         $postsPerPage = $config->get_int('forumPostsPerPage', 15);
         $totalPages = ceil($database->get_one("SELECT COUNT(*) FROM forum_posts WHERE thread_id = ?", [$threadID]) / $postsPerPage);
         $threadTitle = $this->get_thread_title($threadID);
 
-        if (is_null($pageNumber) || !is_numeric($pageNumber)) {
+        if($event->count_args() >= 3) {
+            $pageNumber = $event->get_arg(2);
+            if (!is_numeric($pageNumber)) {
+                $pageNumber = 0;
+            } elseif ($pageNumber <= 0) {
+                $pageNumber = 0;
+            } elseif ($pageNumber >= $totalPages) {
+                $pageNumber = $totalPages - 1;
+            } else {
+                $pageNumber--;
+            }
+        }
+        else {
             $pageNumber = 0;
-        } elseif ($pageNumber <= 0) {
-            $pageNumber = 0;
-        } elseif ($pageNumber >= $totalPages) {
-            $pageNumber = $totalPages - 1;
-        } else {
-            $pageNumber--;
         }
 
         $posts = $database->get_all(

ext/log_db/main.php

@@ -47,10 +47,7 @@ class LogDatabase extends Extension
             if ($user->can(Permissions::VIEW_EVENTLOG)) {
                 $wheres = [];
                 $args = [];
-                $page_num = int_escape($event->get_arg(0));
+                $page_num = $event->try_page_num(0);
-                if ($page_num <= 0) {
-                    $page_num = 1;
-                }
                 if (!empty($_GET["time-start"])) {
                     $wheres[] = "date_sent > :time_start";
                     $args["time_start"] = $_GET["time-start"];

ext/notes/main.php

@@ -384,12 +384,7 @@ class Notes extends Extension
     {
         global $database, $config;
 
-        $pageNumber = $event->get_arg(1);
+        $pageNumber = $event->try_page_num(1) - 1;
-        if (is_null($pageNumber) || !is_numeric($pageNumber) || $pageNumber <= 0) {
-            $pageNumber = 0;
-        } else {
-            $pageNumber--;
-        }
 
         $notesPerPage = $config->get_int('notesNotesPerPage');
 
@@ -419,12 +414,7 @@ class Notes extends Extension
     {
         global $config, $database;
 
-        $pageNumber = $event->get_arg(1);
+        $pageNumber = $event->try_page_num(1) - 1;
-        if (is_null($pageNumber) || !is_numeric($pageNumber) || $pageNumber <= 0) {
-            $pageNumber = 0;
-        } else {
-            $pageNumber--;
-        }
 
         $requestsPerPage = $config->get_int('notesRequestsPerPage');
 
@@ -478,12 +468,7 @@ class Notes extends Extension
     {
         global $config, $database;
 
-        $pageNumber = $event->get_arg(1);
+        $pageNumber = $event->try_page_num(1) - 1;
-        if (is_null($pageNumber) || !is_numeric($pageNumber) || $pageNumber <= 0) {
-            $pageNumber = 0;
-        } else {
-            $pageNumber--;
-        }
 
         $historiesPerPage = $config->get_int('notesHistoriesPerPage');
 
@@ -511,13 +496,7 @@ class Notes extends Extension
         global $config, $database;
 
         $noteID = $event->get_arg(1);
-
+        $pageNumber = $event->try_page_num(2);
-        $pageNumber = $event->get_arg(2);
-        if (is_null($pageNumber) || !is_numeric($pageNumber) || $pageNumber <= 0) {
-            $pageNumber = 0;
-        } else {
-            $pageNumber--;
-        }
 
         $historiesPerPage = $config->get_int('notesHistoriesPerPage');
 

ext/pools/main.php

@@ -173,7 +173,7 @@ class Pools extends Extension
             // What action are we trying to perform?
             switch ($event->get_arg(0)) {
                 case "list": //index
-                    $this->list_pools($page, int_escape($event->get_arg(1)));
+                    $this->list_pools($page, $event->try_page_num(1));
                     break;
 
                 case "new": // Show form for new pools
@@ -779,14 +779,7 @@ class Pools extends Extension
     {
         global $config, $user, $database;
 
-        $pageNumber = int_escape($event->get_arg(2));
+        $pageNumber = $event->try_page_num(2) - 1;
-        if (is_null($pageNumber) || !is_numeric($pageNumber)) {
-            $pageNumber = 0;
-        } elseif ($pageNumber <= 0) {
-            $pageNumber = 0;
-        } else {
-            $pageNumber--;
-        }
 
         $poolID = int_escape($poolID);
         $pool = $this->get_pool($poolID);

ext/setup/main.php

@@ -288,7 +288,11 @@ class Setup extends Extension
             if (!$user->can(Permissions::CHANGE_SETTING)) {
                 $this->theme->display_permission_denied();
             } else {
-                if ($event->get_arg(0) == "save" && $user->check_auth_token()) {
+                if ($event->count_args() == 0) {
+                    $panel = new SetupPanel();
+                    send_event(new SetupBuildingEvent($panel));
+                    $this->theme->display_page($page, $panel);
+                } elseif ($event->get_arg(0) == "save" && $user->check_auth_token()) {
                     send_event(new ConfigSaveEvent($config));
                     $config->save();
                     flash_message("Config saved");
@@ -297,10 +301,6 @@ class Setup extends Extension
                     $page->set_redirect(make_link("setup"));
                 } elseif ($event->get_arg(0) == "advanced") {
                     $this->theme->display_advanced($page, $config->values);
-                } else {
-                    $panel = new SetupPanel();
-                    send_event(new SetupBuildingEvent($panel));
-                    $this->theme->display_page($page, $panel);
                 }
             }
         }

ext/shimmie_api/main.php

@@ -39,10 +39,15 @@ class ShimmieApi extends Extension
             $page->set_type("text/plain");
 
             if ($event->page_matches("api/shimmie/get_tags")) {
-                $tag = $event->get_arg(0);
+                if($event->count_args() > 0) {
-                if (empty($tag) && isset($_GET['tag'])) {
+                    $tag = $event->get_arg(0);
+                }
+                elseif (isset($_GET['tag'])) {
                     $tag = $_GET['tag'];
                 }
+                else {
+                    $tag = null;
+                }
                 $res = $this->api_get_tags($tag);
                 $page->set_data(json_encode($res));
             } elseif ($event->page_matches("api/shimmie/get_image")) {

ext/transcode/main.php

@@ -128,12 +128,13 @@ class TranscodeImage extends Extension
         global $page, $user;
 
         if ($event->page_matches("transcode") && $user->can(Permissions::EDIT_FILES)) {
-            $image_id = int_escape($event->get_arg(0));
+            if($event->count_args() >= 1) {
-            if (empty($image_id)) {
+                $image_id = int_escape($event->get_arg(0));
-                $image_id = isset($_POST['image_id']) ? int_escape($_POST['image_id']) : null;
             }
-            // Try to get the image ID
+            elseif(isset($_POST['image_id'])) {
-            if (empty($image_id)) {
+                $image_id =  int_escape($_POST['image_id']);
+            }
+            else {
                 throw new ImageTranscodeException("Can not resize Image: No valid Image ID given.");
             }
             $image_obj = Image::by_id($image_id);

ext/trash/main.php

@@ -19,11 +19,13 @@ class Trash extends Extension
 
         if ($event->page_matches("trash_restore") && $user->can(Permissions::VIEW_TRASH)) {
             // Try to get the image ID
-            $image_id = int_escape($event->get_arg(0));
+            if($event->count_args() >= 1) {
-            if (empty($image_id)) {
+                $image_id = int_escape($event->get_arg(0));
-                $image_id = isset($_POST['image_id']) ? $_POST['image_id'] : null;
             }
-            if (empty($image_id)) {
+            elseif (isset($_POST['image_id'])) {
+                $image_id = $_POST['image_id'];
+            }
+            else {
                 throw new SCoreException("Can not restore image: No valid Image ID given.");
             }
 

ext/upload/main.php

@@ -187,11 +187,13 @@ class Upload extends Extension
                     throw new UploadException("Can not replace Image: disk nearly full");
                 }
                 // Try to get the image ID
-                $image_id = int_escape($event->get_arg(0));
+                if($event->count_args() >= 1) {
-                if (empty($image_id)) {
+                    $image_id = int_escape($event->get_arg(0));
-                    $image_id = isset($_POST['image_id']) ? $_POST['image_id'] : null;
                 }
-                if (empty($image_id)) {
+                elseif(isset($_POST['image_id'])) {
+                    $image_id = $_POST['image_id'];
+                }
+                else {
                     throw new UploadException("Can not replace Image: No valid Image ID given.");
                 }
 

ext/user/main.php

@@ -53,10 +53,7 @@ class UserPage extends Extension
             } elseif ($event->get_arg(0) == "list") {
                 $limit = 50;
 
-                $page_num = int_escape($event->get_arg(1));
+                $page_num = $event->try_page_num(1);
-                if ($page_num <= 0) {
-                    $page_num = 1;
-                }
                 $offset = ($page_num-1) * $limit;
 
                 $q = "WHERE 1=1";

ext/wiki/main.php

@@ -103,7 +103,7 @@ class Wiki extends Extension
     {
         global $page, $user;
         if ($event->page_matches("wiki")) {
-            if (is_null($event->get_arg(0)) || strlen(trim($event->get_arg(0))) === 0) {
+            if ($event->count_args() == 0 || strlen(trim($event->get_arg(0))) === 0) {
                 $title = "Index";
             } else {
                 $title = $event->get_arg(0);