From 8cb6a76f0a92740312ccbfeff61fa5d823f7ad0f Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@mailu.io>
Date: Mon, 21 Apr 2025 15:58:11 +0200
Subject: [PATCH] post.php: add safe djvu thumbnail generation

---
 post.php | 44 ++++++++++++++++++--------------------------
 1 file changed, 18 insertions(+), 26 deletions(-)

diff --git a/post.php b/post.php
index e4560bb8..e6afe5b6 100644
--- a/post.php
+++ b/post.php
@@ -1448,42 +1448,34 @@ function handle_post(Context $ctx)
                 $image->destroy();
             } else {
                 $mime = \mime_content_type($file['tmp_name']);
-                if ($file['extension'] === "pdf" && $config['pdf_file_thumbnail']) {
-                    if ($mime !== 'application/pdf' && $mime !== 'application/x-pdf') {
-                        error($config['error']['invalidfile']);
-                    }
+                $pdf = $file['extension'] === "pdf" && $config['pdf_file_thumbnail'];
+                $djvu = $file['extension'] === "djvu" && $config['djvu_file_thumbnail'];
 
+                if ($pdf || $djvu) {
                     $e_thumb_path = \escapeshellarg($file['thumb']);
                     $e_file_path = \escapeshellarg($file['tmp_name']);
                     $thumb_width = $config['thumb_width'];
                     $thumb_height = $config['thumb_height'];
 
                     // Generates a PPM image and pipes it directly into convert for resizing + type conversion.
-                    $error = shell_exec_error("gs -dSAFER -dBATCH -dNOPAUSE -dQUIET
-                        -sDEVICE=ppmraw -r100 -dFirstPage=1 -dLastPage=1 -sOutputFile=- $e_file_path
-                        | convert -thumbnail {$thumb_width}x{$thumb_height} ppm:- $e_thumb_path");
+                    if ($pdf && $mime === 'application/pdf') {
+                        $error = shell_exec_error("gs -dSAFER -dBATCH -dNOPAUSE -dQUIET \
+                            -sDEVICE=ppmraw -r100 -dFirstPage=1 -dLastPage=1 -sOutputFile=- $e_file_path \
+                            | convert -thumbnail {$thumb_width}x{$thumb_height} ppm:- $e_thumb_path");
+                    } elseif ($djvu && $mime === 'image/vnd.djvu') {
+                        $error = shell_exec_error("ddjvu -format=ppm -page 1 $e_file_path \
+                            | convert -thumbnail {$thumb_width}x{$thumb_height} ppm:- $e_thumb_path");
+                    } else {
+                        // Mime check failed.
+                        error($config['error']['invalidfile']);
+                    }
 
                     if ($error) {
                         $log = $ctx->get(LogDriver::class);
-                        $log->log(LogDriver::ERROR, 'Could not render thumbnail for PDF file, using static fallback.');
-                        $path = sprintf($config['file_thumb'], isset($config['file_icons'][$file['extension']]) ? $config['file_icons'][$file['extension']] : $config['file_icons']['default']);
-                    }
-
-                    $file['thumb'] = basename($file['thumb']);
-                    $size = @getimagesize($path);
-                    $file['thumbwidth'] = $size[0];
-                    $file['thumbheight'] = $size[1];
-                    $file['width'] = $size[0];
-                    $file['height'] = $size[1];
-                }
-                if ($file['extension'] == "djvu" && $config['djvu_file_thumbnail']) {
-                    $path = $file['thumb'];
-                    $error = shell_exec_error('convert -size ' . $config['thumb_width'] . 'x' . $config['thumb_height'] . ' -thumbnail ' . $config['thumb_width'] . 'x' . $config['thumb_height'] . ' -background white -alpha remove ' .
-                        escapeshellarg($file['tmp_name'] . '[0]') . ' ' .
-                        escapeshellarg($file['thumb']));
-
-                    if ($error) {
-                        $path = sprintf($config['file_thumb'], isset($config['file_icons'][$file['extension']]) ? $config['file_icons'][$file['extension']] : $config['file_icons']['default']);
+                        $log->log(LogDriver::ERROR, 'Could not render thumbnail for PDF/DJVU file, using static fallback.');
+                        $path = \sprintf($config['file_thumb'], isset($config['file_icons'][$file['extension']]) ? $config['file_icons'][$file['extension']] : $config['file_icons']['default']);
+                    } else {
+                        $path = $file['thumb'];
                     }
 
                     $file['thumb'] = basename($file['thumb']);