Correctly exit fetch negotiation for stateless RPC connections

Commit 9530c10192 (2018-02-11)
"Add a minimum negotiation feature for fetch" made fetch
negotiation cheaper for repos with huge numbers of
references (we are seeing a 15x reduction in maximum fetch
times for chromium/chromium/src on trans-Pacific links).
But it inadvertently broke the handling of stateless RPC
connections, so fix that here.

Change-Id: I0090aa76ffecc55801ebb833ac2e0c933a4a7c54
Signed-off-by: Terry Parker <tparker@google.com>

org.eclipse.jgit/src/org/eclipse/jgit/transport/BasePackFetchConnection.java

@@ -634,6 +634,9 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 						// Minimal negotiation was requested and we sent out our
 						// current reference values for our wants, so terminate
 						// negotiation early.
+						if (statelessRPC) {
+							state.writeTo(out, null);
+						}
 						break SEND_HAVES;
 					}
 					break READ_RESULT;
@@ -669,6 +672,9 @@ public abstract class BasePackFetchConnection extends BasePackConnection
 					if (minimalNegotiationSet != null && minimalNegotiationSet.isEmpty()) {
 						// Minimal negotiation was requested and we sent out our current reference
 						// values for our wants, so terminate negotiation early.
+						if (statelessRPC) {
+							state.writeTo(out, null);
+						}
 						break SEND_HAVES;
 					}
 					break;