add a testbugfix/disallow-reading-random-bytes

2 files changed, 17 insertions, 9 deletions

diff --git a/src/entry.rs b/src/entry.rs
index 4feee46..dade633 100644
--- a/src/entry.rs
+++ b/src/entry.rs
@@ -96,14 +96,7 @@ impl EntryHeader {
         let mut signature = [0; 4];
         reader.read_exact(&mut signature)?;
 
-        let mut header_is_valid = false;
-
-        for header in &[FILE_HEADER, BAAD_HEADER, ZERO_HEADER] {
-            if signature == **header {
-                header_is_valid = true;
-                break;
-            }
-        }
+        let header_is_valid = [FILE_HEADER, BAAD_HEADER, ZERO_HEADER].contains(&&signature);
 
         ensure!(
             header_is_valid,
diff --git a/tests/test_cli.rs b/tests/test_cli.rs
index b247ad5..3cac0f5 100644
--- a/tests/test_cli.rs
+++ b/tests/test_cli.rs
@@ -5,7 +5,7 @@ use fixtures::*;
 use assert_cmd::prelude::*;
 use std::fs;
 use std::fs::File;
-use std::io::Read;
+use std::io::{Read, Write};
 use std::process::Command;
 use tempfile::tempdir;
 
@@ -45,6 +45,21 @@ fn test_it_refuses_to_overwrite_directory() {
 }
 
 #[test]
+fn test_non_mft_file_is_error() {
+    let d = tempdir().unwrap();
+
+    let f = d.as_ref().join("test.out");
+
+    let mut file = File::create(&f).unwrap();
+    file.write_all(b"I'm a file!").unwrap();
+
+    let mut cmd = Command::cargo_bin("mft_dump").expect("failed to find binary");
+    cmd.args(&[f.to_str().unwrap()]);
+
+    cmd.assert().failure().code(1);
+}
+
+#[test]
 fn test_it_exports_resident_streams() {
     let d = tempdir().unwrap();