Merge branch 'jk/fetch-reachability-error-fix'

Code clean-up and a fix for "git fetch" by an explicit object name
(as opposed to fetching refs by name).

* jk/fetch-reachability-error-fix:
  fetch: do not consider peeled tags as advertised tips
  remote.c: make singular free_ref() public
  fetch: use free_refs()
  pkt-line: prepare buffer before handling ERR packets
  upload-pack: send ERR packet for non-tip objects
  t5530: check protocol response for "not our ref"
  t5516: drop ok=sigpipe from unreachable-want tests
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 49bf428..c81ca36 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1241,9 +1241,9 @@
 			cd shallow &&
 			# Some protocol versions (e.g. 2) support fetching
 			# unadvertised objects, so restrict this test to v0.
-			test_must_fail ok=sigpipe env GIT_TEST_PROTOCOL_VERSION= \
+			test_must_fail env GIT_TEST_PROTOCOL_VERSION= \
 				git fetch ../testrepo/.git $SHA1_3 &&
-			test_must_fail ok=sigpipe env GIT_TEST_PROTOCOL_VERSION= \
+			test_must_fail env GIT_TEST_PROTOCOL_VERSION= \
 				git fetch ../testrepo/.git $SHA1_1 &&
 			git --git-dir=../testrepo/.git config uploadpack.allowreachablesha1inwant true &&
 			git fetch ../testrepo/.git $SHA1_1 &&
@@ -1251,8 +1251,9 @@
 			test_must_fail git cat-file commit $SHA1_2 &&
 			git fetch ../testrepo/.git $SHA1_2 &&
 			git cat-file commit $SHA1_2 &&
-			test_must_fail ok=sigpipe env GIT_TEST_PROTOCOL_VERSION= \
-				git fetch ../testrepo/.git $SHA1_3
+			test_must_fail env GIT_TEST_PROTOCOL_VERSION= \
+				git fetch ../testrepo/.git $SHA1_3 2>err &&
+			test_i18ngrep "remote error:.*not our ref.*$SHA1_3\$" err
 		)
 	'
 done
@@ -1284,6 +1285,17 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'peeled advertisements are not considered ref tips' '
+	mk_empty testrepo &&
+	git -C testrepo commit --allow-empty -m one &&
+	git -C testrepo commit --allow-empty -m two &&
+	git -C testrepo tag -m foo mytag HEAD^ &&
+	oid=$(git -C testrepo rev-parse mytag^{commit}) &&
+	test_must_fail env GIT_TEST_PROTOCOL_VERSION= \
+		git fetch testrepo $oid 2>err &&
+	test_i18ngrep "Server does not allow request for unadvertised object" err
+'
+
 test_expect_success 'pushing a specific ref applies remote.$name.push as refmap' '
 	mk_test testrepo heads/master &&
 	rm -fr src dst &&
diff --git a/t/t5530-upload-pack-error.sh b/t/t5530-upload-pack-error.sh
index 4f6e32b..a1d3031 100755
--- a/t/t5530-upload-pack-error.sh
+++ b/t/t5530-upload-pack-error.sh
@@ -57,13 +57,25 @@
 	grep "bad tree object" output.err
 '
 
-test_expect_success 'upload-pack error message when bad ref requested' '
+test_expect_success 'upload-pack fails due to bad want (no object)' '
 
 	printf "0045want %s multi_ack_detailed\n00000009done\n0000" \
 		"deadbeefdeadbeefdeadbeefdeadbeefdeadbeef" >input &&
 	test_must_fail git upload-pack . <input >output 2>output.err &&
-	grep -q "not our ref" output.err &&
-	! grep -q multi_ack_detailed output.err
+	grep "not our ref" output.err &&
+	grep "ERR" output &&
+	! grep multi_ack_detailed output.err
+'
+
+test_expect_success 'upload-pack fails due to bad want (not tip)' '
+
+	oid=$(echo an object we have | git hash-object -w --stdin) &&
+	printf "0045want %s multi_ack_detailed\n00000009done\n0000" \
+		"$oid" >input &&
+	test_must_fail git upload-pack . <input >output 2>output.err &&
+	grep "not our ref" output.err &&
+	grep "ERR" output &&
+	! grep multi_ack_detailed output.err
 '
 
 test_expect_success 'upload-pack fails due to error in pack-objects enumeration' '