6 files changed, 137 insertions, 49 deletions

diff --git a/builtin-send-pack.c b/builtin-send-pack.c
index 8fffdbf200..76c72065de 100644
--- a/builtin-send-pack.c
+++ b/builtin-send-pack.c
@@ -406,50 +406,20 @@ int send_pack(struct send_pack_args *args,
 	 */
 	new_refs = 0;
 	for (ref = remote_refs; ref; ref = ref->next) {
-
-		if (ref->peer_ref)
-			hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
-		else if (!args->send_mirror)
+		if (!ref->peer_ref && !args->send_mirror)
 			continue;
 
-		ref->deletion = is_null_sha1(ref->new_sha1);
-		if (ref->deletion && !allow_deleting_refs) {
-			ref->status = REF_STATUS_REJECT_NODELETE;
-			continue;
-		}
-		if (!ref->deletion &&
-		    !hashcmp(ref->old_sha1, ref->new_sha1)) {
-			ref->status = REF_STATUS_UPTODATE;
+		/* Check for statuses set by set_ref_status_for_push() */
+		switch (ref->status) {
+		case REF_STATUS_REJECT_NONFASTFORWARD:
+		case REF_STATUS_UPTODATE:
 			continue;
+		default:
+			; /* do nothing */
 		}
 
-		/* This part determines what can overwrite what.
-		 * The rules are:
-		 *
-		 * (0) you can always use --force or +A:B notation to
-		 *     selectively force individual ref pairs.
-		 *
-		 * (1) if the old thing does not exist, it is OK.
-		 *
-		 * (2) if you do not have the old thing, you are not allowed
-		 *     to overwrite it; you would not know what you are losing
-		 *     otherwise.
-		 *
-		 * (3) if both new and old are commit-ish, and new is a
-		 *     descendant of old, it is OK.
-		 *
-		 * (4) regardless of all of the above, removing :B is
-		 *     always allowed.
-		 */
-
-		ref->nonfastforward =
-		    !ref->deletion &&
-		    !is_null_sha1(ref->old_sha1) &&
-		    (!has_sha1_file(ref->old_sha1)
-		      || !ref_newer(ref->new_sha1, ref->old_sha1));
-
-		if (ref->nonfastforward && !ref->force && !args->force_update) {
-			ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
+		if (ref->deletion && !allow_deleting_refs) {
+			ref->status = REF_STATUS_REJECT_NODELETE;
 			continue;
 		}
 
@@ -673,6 +643,9 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	if (match_refs(local_refs, &remote_refs, nr_refspecs, refspecs, flags))
 		return -1;
 
+	set_ref_status_for_push(remote_refs, args.send_mirror,
+		args.force_update);
+
 	ret = send_pack(&args, fd, conn, remote_refs, &extra_have);
 
 	if (helper_status)
diff --git a/remote.c b/remote.c
index e3afecdb10..c70181cdc6 100644
--- a/remote.c
+++ b/remote.c
@@ -1247,6 +1247,56 @@ int match_refs(struct ref *src, struct ref **dst,
 	return 0;
 }
 
+void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
+	int force_update)
+{
+	struct ref *ref;
+
+	for (ref = remote_refs; ref; ref = ref->next) {
+		if (ref->peer_ref)
+			hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
+		else if (!send_mirror)
+			continue;
+
+		ref->deletion = is_null_sha1(ref->new_sha1);
+		if (!ref->deletion &&
+			!hashcmp(ref->old_sha1, ref->new_sha1)) {
+			ref->status = REF_STATUS_UPTODATE;
+			continue;
+		}
+
+		/* This part determines what can overwrite what.
+		 * The rules are:
+		 *
+		 * (0) you can always use --force or +A:B notation to
+		 *     selectively force individual ref pairs.
+		 *
+		 * (1) if the old thing does not exist, it is OK.
+		 *
+		 * (2) if you do not have the old thing, you are not allowed
+		 *     to overwrite it; you would not know what you are losing
+		 *     otherwise.
+		 *
+		 * (3) if both new and old are commit-ish, and new is a
+		 *     descendant of old, it is OK.
+		 *
+		 * (4) regardless of all of the above, removing :B is
+		 *     always allowed.
+		 */
+
+		ref->nonfastforward =
+			!ref->deletion &&
+			!is_null_sha1(ref->old_sha1) &&
+			(!has_sha1_file(ref->old_sha1)
+			  || !ref_newer(ref->new_sha1, ref->old_sha1));
+
+		if (ref->nonfastforward && !ref->force && !force_update) {
+			ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
+			continue;
+		}
+	}
+}
+
 struct branch *branch_get(const char *name)
 {
 	struct branch *ret;
diff --git a/remote.h b/remote.h
index 8b7ecf9197..6e13643cab 100644
--- a/remote.h
+++ b/remote.h
@@ -98,6 +98,8 @@ char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 
 int match_refs(struct ref *src, struct ref **dst,
 	       int nr_refspec, const char **refspec, int all);
+void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
+	int force_update);
 
 /*
  * Given a list of the remote refs and the specification of things to
diff --git a/t/t5541-http-push.sh b/t/t5541-http-push.sh
index 2a58d0cc9c..83a8e14c6c 100755
--- a/t/t5541-http-push.sh
+++ b/t/t5541-http-push.sh
@@ -88,5 +88,49 @@ test_expect_success 'used receive-pack service' '
 	test_cmp exp act
 '
 
+test_expect_success 'non-fast-forward push fails' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	git checkout master &&
+	echo "changed" > path2 &&
+	git commit -a -m path2 --amend &&
+
+	HEAD=$(git rev-parse --verify HEAD) &&
+	!(git push -v origin >output 2>&1) &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
+	 test $HEAD != $(git rev-parse --verify HEAD))
+'
+
+test_expect_success 'non-fast-forward push show ref status' '
+	grep "^ ! \[rejected\][ ]*master -> master (non-fast-forward)$" output
+'
+
+test_expect_success 'non-fast-forward push shows help message' '
+	grep \
+"To prevent you from losing history, non-fast-forward updates were rejected
+Merge the remote changes before pushing again.  See the '"'non-fast-forward'"'
+section of '"'git push --help'"' for details." output
+'
+
+test_expect_success 'push fails for non-fast-forward refs unmatched by remote helper' '
+	# create a dissimilarly-named remote ref so that git is unable to match the
+	# two refs (viz. local, remote) unless an explicit refspec is provided.
+	git push origin master:retsam
+
+	echo "change changed" > path2 &&
+	git commit -a -m path2 --amend &&
+
+	# push master too; this ensures there is at least one '"'push'"' command to
+	# the remote helper and triggers interaction with the helper.
+	!(git push -v origin +master master:retsam >output 2>&1) &&
+
+	grep "^ + [a-f0-9]*\.\.\.[a-f0-9]* *master -> master (forced update)$" output &&
+	grep "^ ! \[rejected\] *master -> retsam (non-fast-forward)$" output &&
+
+	grep \
+"To prevent you from losing history, non-fast-forward updates were rejected
+Merge the remote changes before pushing again.  See the '"'non-fast-forward'"'
+section of '"'git push --help'"' for details." output
+'
+
 stop_httpd
 test_done
diff --git a/transport-helper.c b/transport-helper.c
index ca8fa92e63..fdf2256220 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -528,24 +528,27 @@ static int push_refs(struct transport *transport,
 		return transport->push_refs(transport, remote_refs, flags);
 	}
 
-	if (!remote_refs)
+	if (!remote_refs) {
+		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
+			"Perhaps you should specify a branch such as 'master'.\n");
 		return 0;
+	}
 
 	helper = get_helper(transport);
 	if (!data->push)
 		return 1;
 
 	for (ref = remote_refs; ref; ref = ref->next) {
-		if (ref->peer_ref)
-			hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
-		else if (!mirror)
+		if (!ref->peer_ref && !mirror)
 			continue;
 
-		ref->deletion = is_null_sha1(ref->new_sha1);
-		if (!ref->deletion &&
-			!hashcmp(ref->old_sha1, ref->new_sha1)) {
-			ref->status = REF_STATUS_UPTODATE;
+		/* Check for statuses set by set_ref_status_for_push() */
+		switch (ref->status) {
+		case REF_STATUS_REJECT_NONFASTFORWARD:
+		case REF_STATUS_UPTODATE:
 			continue;
+		default:
+			; /* do nothing */
 		}
 
 		if (force_all)
@@ -634,6 +637,15 @@ static int push_refs(struct transport *transport,
 			continue;
 		}
 
+		if (ref->status != REF_STATUS_NONE) {
+			/*
+			 * Earlier, the ref was marked not to be pushed, so ignore the ref
+			 * status reported by the remote helper if the latter is 'no match'.
+			 */
+			if (status == REF_STATUS_NONE)
+				continue;
+		}
+
 		ref->status = status;
 		ref->remote_status = msg;
 	}
diff --git a/transport.c b/transport.c
index c3f156ea04..d7db2941fb 100644
--- a/transport.c
+++ b/transport.c
@@ -983,7 +983,7 @@ int transport_push(struct transport *transport,
 		int verbose = flags & TRANSPORT_PUSH_VERBOSE;
 		int quiet = flags & TRANSPORT_PUSH_QUIET;
 		int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
-		int ret;
+		int ret, err;
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
@@ -995,9 +995,16 @@ int transport_push(struct transport *transport,
 			return -1;
 		}
 
+		set_ref_status_for_push(remote_refs,
+			flags & TRANSPORT_PUSH_MIRROR,
+			flags & TRANSPORT_PUSH_FORCE);
+
 		ret = transport->push_refs(transport, remote_refs, flags);
+		err = push_had_errors(remote_refs);
+
+		ret |= err;
 
-		if (!quiet || push_had_errors(remote_refs))
+		if (!quiet || err)
 			print_push_status(transport->url, remote_refs,
 					verbose | porcelain, porcelain,
 					nonfastforward);