From d26b298b3a27e26bd5524ee5b6f16255c5129d8f Mon Sep 17 00:00:00 2001
From: Antoni Boucher <bouanto@zoho.com>
Date: Fri, 10 Feb 2023 15:58:01 -0500
Subject: [PATCH] Update read_skippable_frame to take a Write parameter

---
 src/stream/read/mod.rs   | 10 +++-------
 src/stream/zio/writer.rs |  7 +++++--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/stream/read/mod.rs b/src/stream/read/mod.rs
index e42bfc49..df354374 100644
--- a/src/stream/read/mod.rs
+++ b/src/stream/read/mod.rs
@@ -2,7 +2,7 @@
 #[cfg(feature = "experimental")]
 use std::cmp::min;
 #[cfg(feature = "experimental")]
-use std::io::{SeekFrom, Seek};
+use std::io::{SeekFrom, Seek, Write};
 use std::io::{self, BufRead, BufReader, Read};
 #[cfg(feature = "experimental")]
 use std::mem::size_of;
@@ -106,7 +106,7 @@ impl<'a, R: Read + Seek> Decoder<'a, BufReader<R>> {
 
     /// Attempt to read a skippable frame and write its content to `dest`.
     /// If it cannot read a skippable frame, the reader will be back to its starting position.
-    pub fn read_skippable_frame(&mut self, dest: &mut [u8]) -> io::Result<(usize, MagicVariant)> {
+    pub fn read_skippable_frame<W: Write>(&mut self, dest: &mut W) -> io::Result<(usize, MagicVariant)> {
         let magic_buffer = self.reader.peek_4bytes()?;
         let op = self.reader.operation();
         if !op.is_skippable_frame(&magic_buffer) {
@@ -121,12 +121,8 @@ impl<'a, R: Read + Seek> Decoder<'a, BufReader<R>> {
         self.reader.reader_mut().read_exact(&mut buffer)?;
         let content_size = u32::from_le_bytes(buffer) as usize;
 
-        if content_size > dest.len() {
-            return Err(io::Error::new(io::ErrorKind::Other, "Destination buffer is too small"));
-        }
-
         if content_size > 0 {
-            self.reader.reader_mut().read_exact(&mut dest[..content_size])?;
+            std::io::copy(&mut self.reader.reader_mut().take(content_size as u64), dest)?;
         }
 
         let magic_variant = magic_number - MAGIC_SKIPPABLE_START;
diff --git a/src/stream/zio/writer.rs b/src/stream/zio/writer.rs
index 98758775..1d5139aa 100644
--- a/src/stream/zio/writer.rs
+++ b/src/stream/zio/writer.rs
@@ -346,7 +346,7 @@ mod tests {
         // Decompress and skip a frame.
         let mut decoder = Decoder::new(data).unwrap().single_frame();
 
-        let mut frame = vec![0; 20];
+        let mut frame = vec![];
         let (size, _) = decoder.read_skippable_frame(&mut frame).unwrap();
         assert_eq!("test content", String::from_utf8_lossy(&frame[..size]));
 
@@ -370,6 +370,7 @@ mod tests {
                 .single_frame()
         };
 
+        let mut frame = vec![];
         let (size, _) = decoder.read_skippable_frame(&mut frame).unwrap();
         assert_eq!("SKIP", String::from_utf8_lossy(&frame[..size]));
 
@@ -384,6 +385,7 @@ mod tests {
                 .single_frame()
         };
 
+        let mut frame = vec![];
         let (size, _) = decoder.read_skippable_frame(&mut frame).unwrap();
         assert_eq!("end", String::from_utf8_lossy(&frame[..size]));
 
@@ -432,10 +434,11 @@ mod tests {
                 .single_frame()
         };
 
-        let mut frame = vec![0; 20];
+        let mut frame = vec![];
         let (size, _) = decoder.read_skippable_frame(&mut frame).unwrap();
         assert_eq!("SKIP", String::from_utf8_lossy(&frame[..size]));
 
+        let mut frame = vec![];
         let (size, _) = decoder.read_skippable_frame(&mut frame).unwrap();
         assert_eq!("second skip frame", String::from_utf8_lossy(&frame[..size]));
     }