Accept refs/for/ options via git push -o

Push options are a capability in the Git protocol to transport
arbitrary strings (example usage: topic strings) to the server through
command line flags rather than by the existing Gerrit-specific magic
branch "refs/for/master%..." convention.

For example with Git >= 2.10:

  git push -o r=email -o topic=fix-bug42 origin HEAD:refs/for/master

can now be used instead of:

  git push origin HEAD:refs/for/master%r=email,topic=fix-bug42

Change-Id: I44e7214b9342d461b07c4b6dd638970cf5fb622f
Signed-off-by: Dan Wang <dwwang@google.com>

gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/GitUtil.java

@@ -151,8 +151,15 @@ public class GitUtil {
 
   public static PushResult pushHead(TestRepository<?> testRepo, String ref,
       boolean pushTags, boolean force) throws GitAPIException {
+    return pushHead(testRepo, ref, pushTags, force, null);
+  }
+
+  public static PushResult pushHead(TestRepository<?> testRepo, String ref,
+      boolean pushTags, boolean force, List<String> pushOptions)
+          throws GitAPIException {
     PushCommand pushCmd = testRepo.git().push();
     pushCmd.setForce(force);
+    pushCmd.setPushOptions(pushOptions);
     pushCmd.setRefSpecs(new RefSpec("HEAD:" + ref));
     if (pushTags) {
       pushCmd.setPushTags();

gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java

@@ -16,6 +16,7 @@ package com.google.gerrit.acceptance;
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.gerrit.acceptance.GitUtil.pushHead;
+import static org.junit.Assert.assertEquals;
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
@@ -136,6 +137,7 @@ public class PushOneCommit {
   private String changeId;
   private Tag tag;
   private boolean force;
+  private List<String> pushOptions;
 
   private final TestRepository<?>.CommitBuilder commitBuilder;
 
@@ -275,8 +277,8 @@ public class PushOneCommit {
       }
       tagCommand.call();
     }
-    return new Result(ref, pushHead(testRepo, ref, tag != null, force), c,
+    return new Result(ref,
-        subject);
+        pushHead(testRepo, ref, tag != null, force, pushOptions), c, subject);
   }
 
   public void setTag(final Tag tag) {
@@ -287,6 +289,14 @@ public class PushOneCommit {
     this.force = force;
   }
 
+  public List<String> getPushOptions() {
+    return pushOptions;
+  }
+
+  public void setPushOptions(List<String> pushOptions) {
+    this.pushOptions = pushOptions;
+  }
+
   public void noParents() {
     commitBuilder.noParents();
   }
@@ -326,6 +336,10 @@ public class PushOneCommit {
       return commit;
     }
 
+    public void assertPushOptions(List<String> pushOptions) {
+      assertEquals(pushOptions, getPushOptions());
+    }
+
     public void assertChange(Change.Status expectedStatus,
         String expectedTopic, TestAccount... expectedReviewers)
         throws OrmException, NoSuchChangeException {

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/git/AbstractPushForReview.java

@@ -175,6 +175,21 @@ public abstract class AbstractPushForReview extends AbstractDaemonTest {
     r.assertChange(Change.Status.NEW, topic);
   }
 
+  @Test
+  public void pushForMasterWithTopicOption() throws Exception {
+    String topicOption = "topic=myTopic";
+    List<String> pushOptions = new ArrayList<>();
+    pushOptions.add(topicOption);
+
+    PushOneCommit push = pushFactory.create(db, admin.getIdent(), testRepo);
+    push.setPushOptions(pushOptions);
+    PushOneCommit.Result r = push.to("refs/for/master");
+
+    r.assertOkStatus();
+    r.assertChange(Change.Status.NEW, "myTopic");
+    r.assertPushOptions(pushOptions);
+  }
+
   @Test
   public void pushForMasterWithNotify() throws Exception {
     TestAccount user2 = accounts.user2();

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -42,6 +42,7 @@ import com.google.common.collect.FluentIterable;
 import com.google.common.collect.HashBiMap;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.ListMultimap;
@@ -315,6 +316,8 @@ public class ReceiveCommits {
   private final RequestId receiveId;
   private MagicBranchInput magicBranch;
   private boolean newChangeForAllNotInTarget;
+  private final ListMultimap<String, String> pushOptions =
+      LinkedListMultimap.create();
 
   private List<CreateRequest> newChanges = Collections.emptyList();
   private final Map<Change.Id, ReplaceRequest> replaceByChange =
@@ -490,6 +493,7 @@ public class ReceiveCommits {
     advHooks.add(new HackPushNegotiateHook());
     rp.setAdvertiseRefsHook(AdvertiseRefsHookChain.newChain(advHooks));
     rp.setPostReceiveHook(lazyPostReceive.get());
+    rp.setAllowPushOptions(true);
   }
 
   public void init() {
@@ -915,6 +919,18 @@ public class ReceiveCommits {
   }
 
   private void parseCommands(Collection<ReceiveCommand> commands) {
+    List<String> optionList = rp.getPushOptions();
+    if (optionList != null) {
+      for (String option : optionList) {
+        int e = option.indexOf('=');
+        if (e > 0) {
+          pushOptions.put(option.substring(0, e), option.substring(e + 1));
+        } else {
+          pushOptions.put(option, "");
+        }
+      }
+    }
+
     logDebug("Parsing {} commands", commands.size());
     for (ReceiveCommand cmd : commands) {
       if (cmd.getResult() != NOT_ATTEMPTED) {
@@ -1305,14 +1321,14 @@ public class ReceiveCommits {
       return new MailRecipients(reviewer, cc);
     }
 
-    String parse(CmdLineParser clp, Repository repo, Set<String> refs)
+    String parse(CmdLineParser clp, Repository repo, Set<String> refs,
-        throws CmdLineException {
+        ListMultimap<String, String> pushOptions) throws CmdLineException {
       String ref = RefNames.fullName(
           MagicBranch.getDestBranchName(cmd.getRefName()));
 
+      ListMultimap<String, String> options = LinkedListMultimap.create(pushOptions);
       int optionStart = ref.indexOf('%');
       if (0 < optionStart) {
-        ListMultimap<String, String> options = LinkedListMultimap.create();
         for (String s : COMMAS.split(ref.substring(optionStart + 1))) {
           int e = s.indexOf('=');
           if (0 < e) {
@@ -1321,10 +1337,13 @@ public class ReceiveCommits {
             options.put(s, "");
           }
         }
-        clp.parseOptionMap(options);
         ref = ref.substring(0, optionStart);
       }
 
+      if (!options.isEmpty()) {
+        clp.parseOptionMap(options);
+      }
+
       // Split the destination branch by branch and topic. The topic
       // suffix is entirely optional, so it might not even exist.
       String head = readHEAD(repo);
@@ -1347,6 +1366,19 @@ public class ReceiveCommits {
     }
   }
 
+  /**
+   * Gets an unmodifiable view of the pushOptions.
+   * <p>
+   * The collection is empty if the client does not support push options, or if
+   * the client did not send any options.
+   *
+   * @return an unmodifiable view of pushOptions.
+   */
+  @Nullable
+  public ListMultimap<String, String> getPushOptions() {
+    return ImmutableListMultimap.copyOf(pushOptions);
+  }
+
   private void parseMagicBranch(ReceiveCommand cmd) {
     // Permit exactly one new change request per push.
     if (magicBranch != null) {
@@ -1362,8 +1394,10 @@ public class ReceiveCommits {
     String ref;
     CmdLineParser clp = optionParserFactory.create(magicBranch);
     magicBranch.clp = clp;
+
     try {
-      ref = magicBranch.parse(clp, repo, rp.getAdvertisedRefs().keySet());
+      ref = magicBranch.parse(
+          clp, repo, rp.getAdvertisedRefs().keySet(), pushOptions);
     } catch (CmdLineException e) {
       if (!clp.wasHelpRequestedByOption()) {
         logDebug("Invalid branch syntax");