Copy cache header for 304 response

A HTTP 304 response does not have all header fields.
We have to copy the header from the cache entry.
see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5

Change-Id: I197864ad4f2b103edc4a718afea2a35127b7c203
Signed-off-by: Ralph Bergmann <ralph@the4thfloor.eu>

1 files changed, 15 insertions, 3 deletions

diff --git a/src/com/android/volley/toolbox/BasicNetwork.java b/src/com/android/volley/toolbox/BasicNetwork.java
index c82fc34..42696e2 100644
--- a/src/com/android/volley/toolbox/BasicNetwork.java
+++ b/src/com/android/volley/toolbox/BasicNetwork.java
@@ -20,6 +20,7 @@ import android.os.SystemClock;
 
 import com.android.volley.AuthFailureError;
 import com.android.volley.Cache;
+import com.android.volley.Cache.Entry;
 import com.android.volley.Network;
 import com.android.volley.NetworkError;
 import com.android.volley.NetworkResponse;
@@ -97,9 +98,20 @@ public class BasicNetwork implements Network {
                 responseHeaders = convertHeaders(httpResponse.getAllHeaders());
                 // Handle cache validation.
                 if (statusCode == HttpStatus.SC_NOT_MODIFIED) {
-                    return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED,
-                            request.getCacheEntry() == null ? null : request.getCacheEntry().data,
-                            responseHeaders, true);
+
+                    Entry entry = request.getCacheEntry();
+                    if (entry == null) {
+                        return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED, null,
+                                responseHeaders, true);
+                    }
+
+                    // A HTTP 304 response does not have all header fields. We
+                    // have to use the header fields from the cache entry plus
+                    // the new ones from the response.
+                    // http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5
+                    entry.responseHeaders.putAll(responseHeaders);
+                    return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED, entry.data,
+                            entry.responseHeaders, true);
                 }
 
                 // Some responses such as 204s do not have content.  We must check.