From 9abe17415b7ef347e6037f1166961fc98bfaea35 Mon Sep 17 00:00:00 2001
From: Pierre HUBERT <pierre.git@communiquons.org>
Date: Wed, 8 Jul 2020 17:34:44 +0200
Subject: [PATCH] Fix PDF validation

---
 src/utils/pdf_utils.rs | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/utils/pdf_utils.rs b/src/utils/pdf_utils.rs
index 9b46d46..0d980dd 100644
--- a/src/utils/pdf_utils.rs
+++ b/src/utils/pdf_utils.rs
@@ -2,17 +2,22 @@
 //!
 //! @author Pierre Hubert
 
+use pdf::backend::Backend;
+
 use crate::data::error::{ExecError, ResultBoxError};
 
 /// Check out whether a PDF is a valid PDF or not, by trying to open it
 pub fn is_valid_pdf(file: &bytes::Bytes) -> ResultBoxError<bool> {
-    let pdf = pdf::file::File::new(Vec::from(file.as_ref()));
+    let backend = file.to_vec();
 
-    match pdf.get_num_pages() {
-        Ok(num) if num < 1 =>
-            Err(ExecError::boxed_string(format!("Detected a PDF with {} pages!", num))),
-
-        Ok(_) => Ok(true),
+    match backend.read_xref_table_and_trailer() {
+        Ok((refs, _)) => {
+            if refs.is_empty() {
+                Err(ExecError::boxed_string(format!("Detected a PDF with 0 references (file size: {})!", file.len())))
+            } else {
+                Ok(true)
+            }
+        }
 
         Err(e) => {
             println!("Error while parsing PDF: {}", e);