From 42972297f127446587492ee2f883665bec0a14e1 Mon Sep 17 00:00:00 2001
From: Chris Hennick <4961925+Pr0methean@users.noreply.github.com>
Date: Mon, 29 Apr 2024 13:18:17 -0700
Subject: [PATCH] fix: Rare bug where find_and_parse would give up prematurely
 on detecting a false end-of-CDR header

---
 src/spec.rs  |  4 +++-
 src/write.rs | 20 +++++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/spec.rs b/src/spec.rs
index 2bb1489a..b620c01e 100644
--- a/src/spec.rs
+++ b/src/spec.rs
@@ -70,7 +70,9 @@ impl CentralDirectoryEnd {
                     BYTES_BETWEEN_MAGIC_AND_COMMENT_SIZE as i64,
                 ))?;
                 let cde_start_pos = reader.seek(io::SeekFrom::Start(pos))?;
-                return CentralDirectoryEnd::parse(reader).map(|cde| (cde, cde_start_pos));
+                if let Ok(end_header) = CentralDirectoryEnd::parse(reader) {
+                    return Ok((end_header, cde_start_pos));
+                }
             }
             pos = match pos.checked_sub(1) {
                 Some(p) => p,
diff --git a/src/write.rs b/src/write.rs
index 40e664ca..7c5a4f74 100644
--- a/src/write.rs
+++ b/src/write.rs
@@ -1715,9 +1715,10 @@ mod test {
     use crate::result::ZipResult;
     use crate::types::DateTime;
     use crate::write::SimpleFileOptions;
+    use crate::CompressionMethod::Stored;
     use crate::ZipArchive;
     use std::io;
-    use std::io::{Read, Write};
+    use std::io::{Cursor, Read, Write};
     use std::path::PathBuf;
 
     #[test]
@@ -2199,4 +2200,21 @@ mod test {
         assert_eq!(file.name(), "sleep");
         assert_eq!(file.data_start(), page_size.into());
     }
+
+    #[test]
+    fn test_crash_short_read() {
+        let mut writer = ZipWriter::new(Cursor::new(Vec::new()));
+        let comment: Vec<u8> = vec![
+            1, 80, 75, 5, 6, 237, 237, 237, 237, 237, 237, 237, 237, 44, 255, 191, 255, 255, 255,
+            255, 255, 255, 255, 255, 16,
+        ];
+        writer.set_raw_comment(comment);
+        let options = SimpleFileOptions::default()
+            .compression_method(Stored)
+            .with_alignment(11823);
+        writer.start_file("", options).unwrap();
+        writer.write_all(&[255, 255, 44, 255, 0]).unwrap();
+        let written = writer.finish().unwrap();
+        let new_writer = ZipWriter::new_append(written).unwrap();
+    }
 }