From e9e4ceb61d4a3246fdbdbd3a2bbe787dfc36d1c1 Mon Sep 17 00:00:00 2001
From: Adrian Wielgosik <adrian.wielgosik@gmail.com>
Date: Wed, 27 Nov 2024 21:32:07 +0100
Subject: [PATCH] swf: Memcpy the swf header away instead of creating an entire
 new Vec

---
 swf/src/read.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/swf/src/read.rs b/swf/src/read.rs
index 810e35936ef6..a57d6900e01e 100644
--- a/swf/src/read.rs
+++ b/swf/src/read.rs
@@ -136,7 +136,12 @@ pub fn decompress_swf<'a, R: Read + 'a>(mut input: R) -> Result<SwfBuf> {
         frame_rate,
         num_frames,
     };
-    let data = reader.get_ref().to_vec();
+    let offset = reader.as_slice().as_ptr() as usize - data.as_ptr() as usize;
+    // Remove the header.
+    // As an alternative we could return the entire original buffer with header length,
+    // but that's a nontrivial API change, probably not worth the effort.
+    data.drain(..offset);
+    let mut reader = Reader::new(&data, version);
 
     // Parse the first two tags, searching for the FileAttributes and SetBackgroundColor tags.
     // This metadata is useful, so we want to return it along with the header.