Fix capability negotiation when fetching packs over HTTP.

NEWS

@@ -6,6 +6,9 @@
 
   * Fix fetching packs with side-band-64k capability disabled. (David Keijser, Jelmer Vernooij)
 
+  * Fix capability negotiation when fetching packs over HTTP.
+    (#1072461, William Grant)
+
 0.9.0	2013-05-31
 
  BUG FIXES

dulwich/client.py

@@ -748,7 +748,7 @@ class HttpGitClient(GitClient):
         url = self._get_url(path)
         refs, server_capabilities = self._discover_references(
             "git-upload-pack", url)
-        negotiated_capabilities = server_capabilities
+        negotiated_capabilities = self._fetch_capabilities & server_capabilities
         wants = determine_wants(refs)
         if wants is not None:
             wants = [cid for cid in wants if cid != ZERO_SHA]