From ad07e0e0338324f8ec8414b8a75e91d950f81342 Mon Sep 17 00:00:00 2001
From: Evan Zelkowitz <eze@apache.org>
Date: Fri, 26 Feb 2021 17:39:27 +0000
Subject: [PATCH] Add a check for compress response, if from server and 304,
 then check cache for headers instead of the 304 response

---
 plugins/compress/compress.cc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/plugins/compress/compress.cc b/plugins/compress/compress.cc
index f0b1d8aa0b8..13e5f97dd97 100644
--- a/plugins/compress/compress.cc
+++ b/plugins/compress/compress.cc
@@ -657,6 +657,16 @@ transformable(TSHttpTxn txnp, bool server, HostConfiguration *host_configuration
     return 0;
   }
 
+  // We got a server response but it was a 304
+  // we need to update our data to come from cache instead of
+  // the 304 response which does not need to include all headers
+  if ((server) && (resp_status == TS_HTTP_STATUS_NOT_MODIFIED)) {
+    TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
+    if (TS_SUCCESS != TSHttpTxnCachedRespGet(txnp, &bufp, &hdr_loc)) {
+      return 0;
+    }
+  }
+
   if (TS_SUCCESS != TSHttpTxnClientReqGet(txnp, &cbuf, &chdr)) {
     info("cound not get client request");
     TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);