Preserve ZIP directory semantics in bundle reader

crates/scraft-format/src/bundle.rs

@@ -95,10 +95,11 @@ pub fn read_bundle(bytes: &[u8], limits: BundleLimits) -> Result<(String, HashMa
     let mut session = None;
     let mut files = HashMap::new();
     for index in 0..len {
-        let name = archive.entry_name(index).map_err(zip_error)?.ok_or_else(|| BundleError::Invalid("missing entry".into()))?;
-        if name.ends_with('/') {
+        let is_dir = archive.entry_is_dir(index).map_err(zip_error)?.ok_or_else(|| BundleError::Invalid("missing entry".into()))?;
+        if is_dir {
             continue;
         }
+        let name = archive.entry_name(index).map_err(zip_error)?.ok_or_else(|| BundleError::Invalid("missing entry".into()))?;
         let is_session = !name.contains('/') && Path::new(&name).extension().and_then(OsStr::to_str) == Some(SESSION_EXTENSION);
         let size = archive.declared_size(&name).ok_or_else(|| BundleError::Invalid(format!("{name}: missing entry")))?;
         if is_session && session.is_none() {

crates/zip/src/archive.rs

@@ -78,6 +78,15 @@ impl<'a> Archive<'a> {
         Ok(Some(name.into_owned()))
     }
 
+    /// Whether the entry at `index` is a directory according to ZIP filename conventions.
+    pub fn entry_is_dir(&mut self, index: usize) -> Result<Option<bool>, Error> {
+        if index >= self.zip.len() {
+            return Ok(None);
+        }
+        let file = self.zip.by_index_raw(index).map_err(|error| Error::NotZip(error.to_string()))?;
+        Ok(Some(file.is_dir()))
+    }
+
     /// Do two entries share a name? `zip` then keeps one of them, and which one a writer meant
     /// is not known: a format that must not guess refuses the archive.
     pub fn has_duplicate_names(&self) -> bool {

crates/zip/src/lib.rs

@@ -231,11 +231,14 @@ mod tests {
         zip.write_all(b"1").unwrap();
         zip.start_file("second", opts).unwrap();
         zip.write_all(b"2").unwrap();
+        zip.start_file("folder\\", opts).unwrap();
         let bytes = zip.finish().unwrap().into_inner();
 
-        let mut archive = Archive::open(&bytes, Limits { max_entries: 2, max_total_bytes: 10 }).unwrap();
+        let mut archive = Archive::open(&bytes, Limits { max_entries: 3, max_total_bytes: 10 }).unwrap();
         assert_eq!(archive.entry_name(0).unwrap().as_deref(), Some("first"));
         assert_eq!(archive.entry_name(1).unwrap().as_deref(), Some("second"));
-        assert_eq!(archive.entry_name(2).unwrap(), None);
+        assert_eq!(archive.entry_is_dir(2).unwrap(), Some(true));
+        assert_eq!(archive.entry_name(2).unwrap().as_deref(), Some("folder\\"));
+        assert_eq!(archive.entry_name(3).unwrap(), None);
     }
 }