fix read_bytes in BE mode

src/buffer.rs

@@ -275,15 +275,23 @@ where
     ///
     /// [`ReadError::NotEnoughData`]: enum.ReadError.html#variant.NotEnoughData
     pub fn read_bytes(&self, position: usize, byte_count: usize) -> Result<Vec<u8>> {
-        let mut data = vec![];
+        let mut data = Vec::with_capacity(byte_count);
-        data.reserve_exact(byte_count);
         let mut byte_left = byte_count;
         let max_read = size_of::<usize>() - 1;
         let mut read_pos = position;
         while byte_left > 0 {
             let read = min(byte_left, max_read);
-            let bytes: [u8; USIZE_SIZE] = self.read_usize(read_pos, read * 8)?.to_le_bytes();
+            let raw_bytes = self.read_usize(read_pos, read * 8)?;
-            let usable_bytes = &bytes[0..read];
+            let bytes: [u8; USIZE_SIZE] = if E::is_le() {
+                raw_bytes.to_le_bytes()
+            } else {
+                raw_bytes.to_be_bytes()
+            };
+            let usable_bytes = if E::is_le() {
+                &bytes[0..read]
+            } else {
+                &bytes[8-read..8]
+            };
             data.extend_from_slice(usable_bytes);
             byte_left -= read;
             read_pos += read * 8;

tests/tests.rs

@@ -234,6 +234,20 @@ fn test_from() {
     let _: BitStream<LittleEndian> = BitStream::from(BYTES.to_vec());
 }
 
+#[test]
+fn test_read_str_be() {
+    let bytes = vec![
+        0x48, 0x65, 0x6c, 0x6c,
+        0x6f, 0x20, 0x77, 0x6f,
+        0x72, 0x6c, 0x64, 0,
+        0, 0, 0, 0
+    ];
+    let buffer = BitBuffer::new(bytes, BigEndian);
+    assert_eq!(buffer.read_string(0, Some(13)).unwrap(), "Hello world".to_owned());
+    assert_eq!(buffer.read_string(0, Some(16)).unwrap(), "Hello world".to_owned());
+    assert_eq!(buffer.read_string(0, None).unwrap(), "Hello world".to_owned());
+}
+
 #[test]
 fn read_trait() {
     let buffer = BitBuffer::new(BYTES.to_vec(), BigEndian);