From a143705045a4ff7cfb78fc1c24ae65bee24a063e Mon Sep 17 00:00:00 2001
From: Yury Delendik <ydelendik@mozilla.com>
Date: Mon, 1 Nov 2021 13:38:40 +0000
Subject: [PATCH] Bug 1737837 - Fix truncated storeOptimizedEncoding stream.
 r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D129880
---
 dom/fetch/FetchUtil.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dom/fetch/FetchUtil.cpp b/dom/fetch/FetchUtil.cpp
index 5b2b4fe065f7..8631bb5622cf 100644
--- a/dom/fetch/FetchUtil.cpp
+++ b/dom/fetch/FetchUtil.cpp
@@ -627,7 +627,7 @@ class JSStreamConsumer final : public nsIInputStreamCallback,
     }
     MOZ_RELEASE_ASSERT(ret == Z_STREAM_END);
 
-    dstBytes.shrinkTo(zstream.next_out - compressBegin);
+    dstBytes.shrinkTo(zstream.next_out - dstBytes.begin());
 
     NS_DispatchToMainThread(new StoreOptimizedEncodingRunnable(
         std::move(mCache), std::move(dstBytes)));