From 42038422f6f43926d4103c27587b5db60ebde747 Mon Sep 17 00:00:00 2001
From: Nikita Ofitserov <himikof@gmail.com>
Date: Wed, 24 Aug 2022 17:28:04 +0300
Subject: [PATCH] Fix undefined behavior/crash in GZipEncoder

When the output buffer is full, outbuf[produced] references past the buffer end, leading to UB and a possible assertion failure.
Fixes #1968, #1964
---
 src/GZipEncoder.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/GZipEncoder.cc b/src/GZipEncoder.cc
index 884485ee..41cfce5a 100644
--- a/src/GZipEncoder.cc
+++ b/src/GZipEncoder.cc
@@ -87,7 +87,7 @@ std::string GZipEncoder::encode(const unsigned char* in, size_t length,
       throw DL_ABORT_EX(fmt("libz::deflate() failed. cause:%s", strm_->msg));
     }
     size_t produced = outbuf.size() - strm_->avail_out;
-    out.append(&outbuf[0], &outbuf[produced]);
+    out.append(outbuf.data(), outbuf.data() + produced);
     if (strm_->avail_out > 0) {
       break;
     }