From 5e3d3d9ea9fa5241aa4b2fc0583d1b480aaebcec Mon Sep 17 00:00:00 2001
From: Minh Thai <mthai@google.com>
Date: Tue, 25 Jun 2019 11:40:53 -0700
Subject: [PATCH] HackPushNegotiateHook to retain existing haves line

Since org.eclipse.jgit.transport.ReceivePack.setAdvertisedRefs() clears the
any existing haves line added by the previous AdvertiseRefHook in the chain,
HackPushNegotiateHook should include those in its own haves line.

Change-Id: I51aad7b71f742717faa97112fdff5a0a1da8c4ac
---
 .../git/receive/HackPushNegotiateHook.java    | 24 +++++++------------
 1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/java/com/google/gerrit/server/git/receive/HackPushNegotiateHook.java b/java/com/google/gerrit/server/git/receive/HackPushNegotiateHook.java
index 251a79969c..0076e7a804 100644
--- a/java/com/google/gerrit/server/git/receive/HackPushNegotiateHook.java
+++ b/java/com/google/gerrit/server/git/receive/HackPushNegotiateHook.java
@@ -21,7 +21,6 @@ import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.git.ObjectIds;
 import java.io.IOException;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
 import org.eclipse.jgit.lib.ObjectId;
@@ -92,35 +91,30 @@ public class HackPushNegotiateHook implements AdvertiseRefsHook {
 
   private Set<ObjectId> history(Collection<Ref> refs, BaseReceivePack rp) {
     Set<ObjectId> alreadySending = rp.getAdvertisedObjects();
-    if (alreadySending.isEmpty()) {
-      alreadySending = idsOf(refs);
-    }
-
-    int max = MAX_HISTORY - Math.max(0, alreadySending.size() - refs.size());
-    if (max <= 0) {
-      return Collections.emptySet();
+    if (MAX_HISTORY <= alreadySending.size()) {
+      return alreadySending;
     }
 
     // Scan history until the advertisement is full.
     RevWalk rw = rp.getRevWalk();
     rw.reset();
     try {
-      for (Ref ref : refs) {
+      Set<ObjectId> tips = idsOf(refs);
+      for (ObjectId tip : tips) {
         try {
-          if (ref.getObjectId() != null) {
-            rw.markStart(rw.parseCommit(ref.getObjectId()));
-          }
+          rw.markStart(rw.parseCommit(tip));
         } catch (IOException badCommit) {
           continue;
         }
       }
 
-      Set<ObjectId> history = Sets.newHashSetWithExpectedSize(max);
+      Set<ObjectId> history = Sets.newHashSetWithExpectedSize(MAX_HISTORY);
+      history.addAll(alreadySending);
       try {
         int stepCnt = 0;
-        for (RevCommit c; history.size() < max && (c = rw.next()) != null; ) {
+        for (RevCommit c; history.size() < MAX_HISTORY && (c = rw.next()) != null; ) {
           if (c.getParentCount() <= 1
-              && !alreadySending.contains(c)
+              && !tips.contains(c)
               && (history.size() < BASE_COMMITS || (++stepCnt % STEP_COMMITS) == 0)) {
             history.add(c);
           }