Merge branch 'jc/upload-pack-send-symref' into maint

One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess.  A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.

* jc/upload-pack-send-symref:
  t5570: Update for clone-progress-to-stderr branch
  t5570: Update for symref capability
  clone: test the new HEAD detection logic
  connect: annotate refs with their symref information in get_remote_head()
  connect.c: make parse_feature_value() static
  upload-pack: send non-HEAD symbolic refs
  upload-pack: send symbolic ref information as capability
  upload-pack.c: do not pass confusing cb_data to mark_our_ref()
  t5505: fix "set-head --auto with ambiguous HEAD" test

3 files changed, 17 insertions, 12 deletions

diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 8f6e3922dc..ac79dd915d 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -160,9 +160,7 @@ cat >test/expect <<EOF
 * remote two
   Fetch URL: ../two
   Push  URL: ../three
-  HEAD branch (remote HEAD is ambiguous, may be one of the following):
-    another
-    master
+  HEAD branch: master
   Local refs configured for 'git push':
     ahead  forces to master  (fast-forwardable)
     master pushes to another (up to date)
@@ -262,16 +260,12 @@ test_expect_success 'set-head --auto' '
 	)
 '
 
-cat >test/expect <<\EOF
-error: Multiple remote HEAD branches. Please choose one explicitly with:
-  git remote set-head two another
-  git remote set-head two master
-EOF
-
-test_expect_success 'set-head --auto fails w/multiple HEADs' '
+test_expect_success 'set-head --auto has no problem w/multiple HEADs' '
 	(
 		cd test &&
-		test_must_fail git remote set-head --auto two >output 2>&1 &&
+		git fetch two "refs/heads/*:refs/remotes/two/*" &&
+		git remote set-head --auto two >output 2>&1 &&
+		echo "two/HEAD set to master" >expect &&
 		test_i18ncmp expect output
 	)
 '
diff --git a/t/t5570-git-daemon.sh b/t/t5570-git-daemon.sh
index 1309702ba4..e06146835c 100755
--- a/t/t5570-git-daemon.sh
+++ b/t/t5570-git-daemon.sh
@@ -37,7 +37,7 @@ test_expect_success 'fetch changes via git protocol' '
 	test_cmp file clone/file
 '
 
-test_expect_failure 'remote detects correct HEAD' '
+test_expect_success 'remote detects correct HEAD' '
 	git push public master:other &&
 	(cd clone &&
 	 git remote set-head -d origin &&
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index b3b11e61c0..f8e5a9a4ae 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -285,4 +285,15 @@ test_expect_success NOT_MINGW,NOT_CYGWIN 'clone local path foo:bar' '
 	git clone "./foo:bar" foobar
 '
 
+test_expect_success 'clone from a repository with two identical branches' '
+
+	(
+		cd src &&
+		git checkout -b another master
+	) &&
+	git clone src target-11 &&
+	test "z$( cd target-11 && git symbolic-ref HEAD )" = zrefs/heads/another
+
+'
+
 test_done